Digital indicator on K176IE4. Counters-decoders K176IE3, K176IE4 Chip k176ie4 description and their application

We understand how K176IE4 works. In this article I want to talk about the principle of working with the K176IE4 - an indispensable driver for seven-segment indicators. I propose to analyze its work using this circuit as an example: Do not be alarmed - although the circuit looks massive, despite this it is very simple, only 29 electronic components are used. The principle of operation of K176IE4: K176IE4 is inherently a very simple microcircuit to understand. It is a decimal counter with a decoder for seven-segment display. It has 3 signal inputs and 9 signal outputs. The rated supply voltage is from 8.55 to 9.45V. The maximum current per output is 4mA The inputs are: A timing line (4 legs of the microcircuit) - a signal comes along it that forces the microcircuit to switch its states, that is, to count Choice of a common anode / cathode (6 leg) - by connecting this line to the minus, we can control the indicator with a common cathode, to the plus - with a common anode Reset (5th leg) - when log. 1 resets the counter to zero, when submitting a log. 0 - allows the microcircuit to switch states Outputs: 7 outputs to a seven-segment indicator (1, 8-13 legs) Timing signal divided by 4 (3 legs) - needed for clock circuits, we do not use the Timing signal divided by 10 (2 legs) - allows combine several K176IE4, expanding the range of digits (you can add tens, hundreds, etc.) The counting principle works in such a way that when we switch the signal on the timing line from the log. 0 to log. 1 the current value is increased by one The principle of operation of this circuit: To simplify the perception of the operation of this circuit, you can make the following sequence: NE555 issues a rectangular pulse K176IE4 under the influence of the pulse increases its state by one Its current state is transmitted to the transistor assembly ULN2004 for amplification The amplified signal is fed to the LEDs The indicator displays the current state This circuit switches the IE4 states once per second (this period of time is formed by an RC circuit consisting of R1, R2 and C2) NE555 can be easily replaced with KR1006VI1 C3 can be selected in the range from 10 to 100nF The amplifier is required since the maximum the current per output IE4 is 4mA, and the rated current of most LEDs is 20mA Seven-segment indicators will fit any with a common anode and rated voltage from 1.8 to 2.5V, with a current from 10 to 30mA We connect the 6th leg of the microcircuit to the power supply minus, but we use the indicator with a common anode, this is due to the fact that ULN2004 not only amplifies, but also inverts the signal The microcircuit resets its state when power is applied (made by a chain of C4 and R4) or by pressing a button (S1 and R3). Resetting when power is applied is necessary because, otherwise, the microcircuit will not work normally.The resistor in front of the reset button is necessary for the safe operation of the button - almost all clock buttons are designed for a current of no more than 50mA, and therefore we must choose a resistor in the range of 9V / 50mA \u003d 180Ω and up to 1kOhm Author: arssev1 Taken from http://cxem.net 20 pcs. NE555 NE555P NE555N 555 DIP-8. US $ 0.99 / Lot

In this article I want to talk about the principle of working with the K176IE4 - an indispensable driver for seven-segment indicators. I propose to analyze his work using the example of this scheme:

Do not be alarmed - although the circuit looks massive, it is very simple, only 29 electronic components are used

The principle of operation of K176IE4:

K176IE4 is a very simple microcircuit in its essence. It is a decimal counter with a decoder for seven-segment display. It has 3 signal inputs and 9 signal outputs.

The rated supply voltage is from 8.55 to 9.45V. Maximum current per output - 4mA

The inputs are:

• The timing line (4 legs of the microcircuit) - a signal comes along it, which makes the microcircuit switch its states, that is, to count
• The choice of a common anode / cathode (6 leg) - connecting this line to the minus, we can control the indicator with a common cathode, to the plus - with a common anode
• Reset (5 legs) - when submitting a log. 1 resets the counter to zero, when submitting a log. 0 - allows the microcircuit to switch states

• 7 outputs for a seven-segment indicator (1, 8-13 legs)
• Timing signal divided by 4 (3 legs) - needed for clock circuits, not used by us
• Timing signal divided by 10 (2 legs) - allows you to combine several K176IE4, expanding the range of digits (you can add tens, hundreds, etc.)

The counting principle works in such a way that when we switch the signal on the clock line from the log. 0 to log. 1 current value is increased by one

How this circuit works:

To simplify the perception of the operation of this scheme, you can make the following sequence:

1. NE555 outputs square wave
2. K176IE4 under the influence of an impulse increases its state by one
3. Its current state is transmitted to the ULN2004 transistor assembly for amplification
4. The amplified signal goes to the LEDs
5. The indicator displays the current state

This circuit switches the IE4 states once per second (this period of time is formed by an RC circuit consisting of R1, R2 and C2)

NE555 can be safely replaced with KR1006VI1

C3 can be selected from 10 to 100nF

The amplifier is necessary since the maximum current per output of IE4 is 4mA, and the rated current of most LEDs is 20mA

Seven-segment indicators will fit any with a common anode and rated voltage from 1.8 to 2.5V, with current from 10 to 30mA

We connect the 6th leg of the microcircuit to the minus of the power supply, but at the same time we use an indicator with a common anode, this is due to the fact that ULN2004 not only amplifies, but also inverts the signal

The microcircuit resets its state when power is applied (made by a chain of C4 and R4) or by pressing a button (S1 and R3). A power-on reset is necessary as otherwise the microcircuit will not work normally

The resistor in front of the reset button is necessary for the safe operation of the button - almost all clock buttons are designed for a current of no more than 50mA, and therefore we must choose a resistor in the range from 9V / 50mA \u003d 180Ω and up to 1kΩ

List of radioelements

There are K176IE3 and K176IE4 microcircuits containing a counter and a decoder designed to work with a seven-segment indicator. The microcircuits have the same pinouts and packages (shown in Figure 1A and 1B for the example of the K176IE4 microcircuit), the difference is that the K176IE3 counts up to 6, and the K176IE4 up to 10. Microcircuits are intended for electronic clocks, so the K176IE3 counts up to 6, for example, if you need to count tens of minutes or seconds.

In addition, both microcircuits have an additional pin (pin 3). In the K176IE4 microcircuit, a unit appears at this pin at the moment when its counter goes into state "4". And in the K176IE3 microcircuit, a unit appears at this output at the moment when the counter counts to 2.
Thus, the presence of these conclusions makes it possible to build an hour counter that counts up to 24.

Consider the K176IE4 microcircuit (Figure 1A and 1B). The input "C" (pin 4) is supplied with pulses that the microcircuit should read and display their number in a seven-segment form on a digital indicator. Input "R" (pin 5) is used to force the counter of the microcircuit to zero. When a logical unit is applied to it, the counter goes to a zero state, and the indicator connected to the output of the microcircuit decoder will display the figure "0", expressed in seven-segment form (see lesson # 9).

The microcircuit counter has a carry output "P" (pin 2). The microcircuit counts up to 10 on this pin, a logical unit. As soon as the microcircuit reaches 10 (the tenth pulse arrives at its input "C") it automatically returns to the zero state, and at this moment (between the fall of the 9th pulse and the front of the 10th) a negative pulse is formed at the output of the IR " zero drop).

The presence of this "P" output makes it possible to use the microcircuit as a frequency divider by 10, because the frequency of the pulses at this output will be 10 times lower than the frequency of the pulses arriving at the "C" input (every 10 pulses at the "C" input, - at output "P" produces one pulse). But the main purpose of this output (IRI) is to organize a multi-discharge counter.

Another input is "S" (pin 6), it is needed to select the type of indicator with which the microcircuit will work. If this is an LED indicator with a common cathode (see lesson # 9), then to work with it, you need to apply a logical zero to this input. If the indicator is with a common anode, you need to supply a unit.

Outputs "A-G" are used to control the segments of the LED indicator, they are connected to the corresponding inputs of the seven-segment indicator.

The K176IE3 microcircuit works in the same way as the K176IE4, but it only counts up to 6, and a unit appears on its pin 3 when its counter counts to 2. The rest of the microcircuit does not differ from the K176IEZ.

Fig. 2
To study the K176IE4 microcircuit, assemble the circuit shown in Figure 2. A pulse shaper is built on the D1 microcircuit (K561LE5 or K176LE5). After each pressing and releasing of the S1 button, one pulse is formed at its output (at pin 3 of D1.1). These pulses are fed to the "C" input of the D2 - K176IE4 microcircuit. Button S2 serves to supply a single logic level to the input "R" D2, in order to translate, thus, the counter of the microcircuit to the zero position.

LED indicator H1 is connected to outputs A-G of microcircuit D2. In this case, an indicator with a common anode is used, therefore, to ignite its segments, there must be zeros at the corresponding outputs D2. To switch the D2 microcircuit to the operating mode with such indicators, a unit is fed to its input S (pin 6).

Using a voltmeter P1 (tester, multimeter, included in the voltage measurement mode), you can observe the change in logic levels at the transfer output (pin 2) and at the output "4" (pin 3).

Set D2 to zero (push and release S2). The H1 indicator will show the number "0". Then, by pressing the S1 button, follow the operation of the counter from "0" to "9", and the next time it is pressed, it goes back to "0". Then place the P1 probe on the D2 pin 3 and press S1. At first, while counting from zero to three, this pin will be zero, but with the appearance of the number "4" - this pin will be one (device P1 will show a voltage close to the supply voltage).

Try to connect pins 3 and 5 of the D2 microcircuit together using a piece of mounting wire (shown by a dashed line in the diagram). Now the counter, having reached zero, will count only up to "4". That is, the indicator readings will be "0", "1", "2", "3" and again "0" and then in a circle. Pin 3 allows you to limit the chip count to four.

Fig. 3
Place the P1 probe on pin 2 of D2. All the time the device will show one, but after the 9th pulse, at the moment of arrival of the 10th pulse and the transition to zero, here the level will fall to zero, and then, after the tenth, it will again become unity. Using this pin (output P), you can organize a multi-digit counter. Figure 3 shows a diagram of a two-digit counter built on two K176IE4 microcircuits. The pulses to the input of this counter come from the output of the multivibrator on the elements D1.1 and D1.2 of the K561LE5 (or K176LE5) microcircuit.

The counter on D2 counts the units of pulses, and after every ten pulses received at its input "C", one pulse appears at its output "P". The second counter - D3 counts these pulses (coming from the "P" output of the D2 counter) and its indicator shows dozens of pulses received at the D2 input from the multivibrator output.

Thus, this two-digit counter counts from "00" to "99" and goes to zero at the arrival of the 100th pulse.

If we need this two-digit counter to count to "39" (goes to zero with the arrival of the 40th pulse), we need to connect pin 3 of D3 using a piece of wiring wire to the pins 5 of both counters connected together. Now, with the end of the third dozen input pulses, a unit from pin 3 of D3 will go to the "R" inputs of both counters and force them to zero.

Fig. 4
To study the K176IE3 microcircuit, assemble the circuit shown in Figure 4. The circuit is the same as in Figure 2. The difference is that the microcircuit will count from "0" to "5", and when the 6th pulse arrives, go to the zero state. On pin 3, a unit will appear when the second pulse arrives at the input. The carry pulse on pin 2 will appear with the arrival of the 6th input pulse. While it counts up to 5 at pin 2 - one, with the arrival of the 6th pulse at the moment of transition to zero - logical zero.

Using two microcircuits K176IE3 and K176IE4, you can build a counter, similar to that used in an electronic clock to count seconds or minutes, that is, a counter that counts up to 60. Figure 5 shows a diagram of such a counter. The circuit is the same as in Figure 3, but the difference is that K176IE3 is used as a D3 chip together with K176IE4.

Fig. 5
And this microcircuit counts up to 6, which means the number of tens will be 6. The counter will count "00" to "59", and with the arrival of the 60th pulse, it will go to zero. If the resistance of the resistor R1 is chosen so that the pulses at the output of D1.2 follow with a period of one second, then you can get a stopwatch that works up to one minute.

Using these microcircuits, it is not difficult to build an electronic clock.

The operation of the digital frequency counter is based on the measurement of the number of input pulses over a reference time interval of 1 second.

The signal under investigation is fed to the input of a pulse shaper, which is assembled on a transistor VT1 and an element DD3.1, which generates rectangular electrical oscillations corresponding to the frequency of the input signal.

Specifications

• Measurement time, s - 1
• Maximum measured frequency, Hz - 9999
• Input signal amplitude, V - 0.05 ... 15
• Supply voltage, V - 9.

Schematic diagram

These impulses are fed to the DD3.2 electronic key. The other input of the key (pin 5 DD3.2) from the control device receives pulses of the exemplary frequency that hold the key open for 1 second.

As a result, at the output of the key (pin 4 of element DD3.2), bursts of pulses are formed, which are fed to the input of the counter DD4 (pin 4).

Figure: 1. Schematic diagram of a digital frequency meter on microcircuits.

An exemplary frequency generator (Fig. 1) is assembled on a DD1 microcircuit and a ZQ1 quartz resonator. Pulses from it are sent to the control device, which is the D-flip-flop DD2. The flip-flop divides the clock frequency by two.

The leading edge of the input pulse switches the flip-flop to a single state. There is a short-term reset of the DD4 ... DD7 counters. A low level signal arrives at the VT2 transistor and closes it, so the HL1 ... HL4 indicators go out. The DD3.2 key is allowed to work, and the pulses are fed to the counter input.

The next pulse of the reference frequency switches the DD2 trigger to the zero state. DD3.2 key is closed. The high-level signal from pin 2 of the DD2 microcircuit opens the transistor VT2 and turns on the HL1 ... HL4 indicators, which display the measurement result for 1 second.

Details

The circuit uses quartz ZQ1 at a frequency of 32768 Hz. Chips K176TM2 and K176LA7 can be replaced with K561TM2 and K561LA7, respectively. Instead of K176IE12, you can apply K176IE5, with the appropriate circuit correction.

The series of microcircuits under consideration includes a large number of counters of various types, most of which operate in weight codes.

K176IE1 microcircuit (Fig. 172) is a six-bit binary counter operating in the 1-2-4-8-16-32 code. The microcircuit has two inputs: input R - setting the counter triggers to 0 and input C - input for supplying counting pulses. Setting to 0 occurs when submitting a log. 1 to input R, switching the triggers of the microcircuit - according to the decay of positive-polarity pulses applied to input C. When building

multi-bit frequency dividers, inputs C of microcircuits should be connected to the outputs of 32 previous ones.

The K176IE2 microcircuit (Fig. 173) is a five-digit counter that can operate as a binary counter in the 1-2-4-8-16 code when a log is supplied. 1 to the control input A, or as a decade with a trigger connected to the output of the decade when log. 0 at input A. In the second case, the counter operation code is 1-2-4-8-10, the total division factor is 20. Input R is used to set counter triggers to 0 by applying a log to this input. 1. The first four counter flip-flops can be set to a single state by giving a log. 1 for inputs SI - S8. Inputs S1 - S8 prevail over input R.

The K176IE2 microcircuit is found in two varieties. ICs of early releases have CP and CN inputs for supplying clock pulses of positive and negative polarity, respectively, turned on by OR. When positive polarity pulses are applied to the CP input, the CN input must be log. 1, when applying pulses of negative polarity to the CN input, the input of the CP should be log. 0. In both cases, the counter switches on the pulse decays.

Another type has two equal inputs for supplying clock pulses (pins 2 and 3), collected by I. The counting occurs according to the decays of positive-polarity pulses applied to any of these inputs, and a log should be sent to the second of these inputs. 1. You can also apply pulses to the combined pins 2 and 3. The microcircuits investigated by the author, released in February and November 1981, belong to the first variety, released in June 1982 and June 1983, to the second.

If you send a log to pin 3 of the K176IE2 microcircuit. 1, both types of microcircuits at the CP input (pin 2) work the same way.

When log. 0 at input A, the order of the triggers corresponds to the timing diagram shown in Fig. 174. In this mode, at the output P, \u200b\u200bwhich is the output of the AND-NOT element, the inputs of which are connected to outputs 1 and 8 of the counter, pulses of negative polarity are allocated, the edges of which coincide with the decay of every ninth input pulse, the decays - with the decay of every tenth.

When connecting the K176IE2 microcircuits to a multi-bit counter, the CP inputs of the subsequent microcircuits should be connected to outputs 8 or 16/10 directly, and a log should be applied to the CN inputs. 1. At the moment of switching on the supply voltage, the triggers of the K176IE2 microcircuit can be set to an arbitrary state. If at the same time the counter is included in the decimal counting mode, that is, a log is sent to input A. 0, and this state is more than 11, the counter "loops" between states 12-13 or 14-15. In this case, pulses are formed at outputs 1 and P with a frequency that is 2 times lower than the frequency of the input signal. In order to exit this mode, the counter must be set to zero by applying a pulse to input R. You can ensure reliable operation of the counter in decimal mode by connecting input A to output 4. Then, being in state 12 or greater, the counter switches to binary mode. counts and leaves the "forbidden zone", setting after state 15 to zero. At the moments of transition from state 9 to state 10, a log is sent to input A from output 4. 0 and the counter is reset to zero in decimal mode.

To indicate the state of decades using the K176IE2 microcircuit, you can use gas-discharge indicators controlled through the K155ID1 decoder. To match the K155ID1 and K176IE2 microcircuits, you can use the K176PU-3 or K561PU4 microcircuits (Fig. 175, a) or pnp transistors (Fig. 175, b).

Microcircuits K176IE3 (Fig. 176), K176IE4 (Fig. 177) and K176IE5 are designed specifically for use in electronic watches with seven-segment displays. K176IE4 microcircuit (Fig. 177) -decade with a counter code converter into a seven-segment indicator code. The microcircuit has three inputs - input R, setting the counter triggers to 0 occurs when the log is supplied. 1 to this input, input C - the triggers are switched by the decay of the positive impulses

polarity at this input. The S input signal controls the polarity of the output signals.

At outputs a, b, c, d, e, f, g - output signals providing the formation of digits on the seven-segment indicator corresponding to the counter state. When submitting a log. 0 to the control input S log. 1 at outputs a, b, c, d, e, f, g correspond to the inclusion of the corresponding segment. If the log is sent to the S input. 1, the inclusion of segments will correspond to the log. 0 at outputs a, b, c, d, e, f, g. Possibility of switching the polarity of output signals significantly expands the scope of microcircuits.

Output P of the microcircuit is the transfer output. The decay of a pulse of positive polarity at this output is formed at the moment the counter transitions from state 9 to state 0.

It should be borne in mind that the pinout of a, b, c, d, e, f, g in the microcircuit passport and in some reference books is given for a non-standard arrangement of indicator segments. In fig. 176, 177, the pinouts are given for the standard segment locations shown in Fig. 111.

Two options for connecting vacuum seven-segment indicators to the K176IE4 microcircuit using transistors are shown in Fig. 178. The heating voltage Uh is selected in accordance with the type of indicator used, by selecting the voltage +25 ... 30 V in the circuit fig. 178 (a) and -15 ... 20 V in the circuit in Fig. 178 (b), the brightness of the indicator segments can be adjusted within certain limits. Transistors in Fig. 178 (6) can be any silicon p-n-p with a collector junction reverse current not exceeding 1 μA at a voltage of 25 V, If the reverse current of the transistors is greater than this value or germanium transistors are used, between the anodes and one of the terminals of the filament indicator must include resistors 30 ... 60 kOhm.

To match the K176IE4 microcircuit with vacuum indicators, it is convenient, in addition, to use the K168KT2B or K168KT2V microcircuits (Fig. 179), as well as KR168KT2BV, K190KT1, K190KT2, K161KN1, K161KN2. The connection of the K161KN1 and K161KN2 microcircuits is illustrated in Fig. 180. When using the K161KN1 inverting microcircuit, a log should be submitted to the S input of the K176IE4 microcircuit. 1, when using a non-inverting microcircuit K161KN2 - log. 0.

In fig. 181 shows options for connecting semiconductor indicators to the K176IE4 microcircuit, Fig. 181 (a) with a common cathode, in Fig. 181 (b) - with a common anode. Resistors R1 - R7 set the required current through the segments of the indicator.

The smallest indicators can be connected to the outputs of the microcircuit directly (Fig. 181, c). However, due to the large spread of the short-circuit current of the microcircuits, which is not standardized by the technical conditions, the brightness of the indicators can also have a large spread. It can be partially compensated by selecting the supply voltage of the indicators.

To match the K176IE4 microcircuit with semiconductor indicators with a common anode, you can use the K176PU1, K176PU2, K176PU-3, K561PU4, KR1561PU4, K561LN2 microcircuits (Fig. 182). When using non-inverting microcircuits, a log should be applied to the S input of the microcircuit. 1, when using inverting - log. 0.

According to the diagram in Fig. 181 (b), excluding the resistors R1 - R7, you can also connect incandescent indicators, while the supply voltage of the indicators must be set approximately 1 V more than the nominal to compensate for the voltage drop across the transistors.This voltage can be either constant or pulsating, obtained as a result of straightening without filtration.

Liquid crystal indicators do not require special coordination, but to turn them on, a source of rectangular pulses with a frequency of 30-100 Hz and a duty cycle of 2 is required, the amplitude of the pulses must correspond to the supply voltage of the microcircuits.

Pulses are applied simultaneously to the input S of the microcircuit and to the common electrode of the indicator (Fig. 183) As a result, a voltage of varying polarity is applied to the segments that need to be indicated relative to the common electrode of the indicator, on the segments that do not need to be indicated, the voltage relative to the common electrode is zero

The K176IE-3 microcircuit (Figure 176) differs from the K176IE4 in that its counter has a conversion factor of 6, and log 1 at output 2 appears when the counter is set to state 2.

The K176IE5 microcircuit contains a crystal oscillator with an external resonator at 32768 Hz and a nine-bit frequency divider and a six-bit frequency divider connected to it, the structure of the microcircuit is shown in Fig. 184 (a) A typical circuit for switching on the microcircuit is shown in Fig. 184 (b). Quartz resonator, resistors R1 and R2, capacitors C1 and C2 The output signal of the crystal oscillator can be monitored at the outputs K and R A signal with a frequency of 32768 Hz is fed to the input of a nine-bit binary frequency divider, from its output 9 a signal with a frequency of 64 Hz can be fed to the input 10 six-digit divider At the output of the 14th fifth digit of this divider, a frequency of 2 Hz is formed, at the output of the 15th sixth digit - 1 Hz. A signal with a frequency of 64 Hz can be used to connect liquid crystal indicators to the outputs of the K176IE- and K176IE4 microcircuits.

Input R serves to reset the triggers of the second divider and set the initial phase of oscillations at the outputs of the microcircuit. When serving

log. 1 at the input R at outputs 14 and 15 - log. 0, after removing the log. 1, pulses appear at these outputs with the appropriate frequency, the decay of the first pulse at output 15 occurs 1 s after the log is removed. one.

When submitting a log. 1 to input S, all triggers of the second divider are set to state 1, after removing the log. 1 from this input, the decay of the first pulse at outputs 14 and 15 occurs almost immediately. Usually the S input is permanently connected to the common wire.

Capacitors C1 and C2 are used to accurately set the frequency of the crystal oscillator. The capacity of the first of them can range from units to one hundred picofarads, the capacity of the second - -0 ... 100 pF. With an increase in the capacity of the capacitors, the generation frequency decreases. It is more convenient to accurately set the frequency using trimming capacitors connected in parallel to C1 and C2. In this case, a capacitor connected in parallel with C2, a rough adjustment is carried out, connected in parallel with C1 - accurate.

The resistance of the resistor R 1 can be in the range of 4.7 ... 68 MΩ, however, when its value is less than 10 MΩ, they are excited

not all quartz resonators.

K176IE8 and K561IE8 microcircuits are decimal counters with a decoder (Fig. 185). The microcircuits have three inputs - an input for setting the initial state R, an input for supplying counting pulses of negative polarity CN and an input for supplying counting pulses of positive polarity CP. The counter is set to 0 when the log is applied to the R input. 1, while at output 0 a log appears. 1, at outputs 1-9 - log. 0.

The counter is switched according to the slopes of the pulses of negative polarity applied to the CN input, while the CP input must have a log. 0. You can also send pulses of positive polarity to the input of the CP, switching will occur according to their slopes. At the same time, there should be a log at the CN input. 1. The timing diagram of the microcircuit is shown in Fig. 186.

Microcircuit K561IE9 (Fig. 187) - a counter with a decoder, the operation of the microcircuit is similar to that of the microcircuits K561IE8

and K176IE8, but the conversion factor and the number of outputs of the decoder 8, not 10. The timing diagram of the microcircuit is shown in Fig. 188. As well as the K561IE8 microcircuit, the microcircuit:

The K561IE9 is based on a cross-coupled shift register. When the supply voltage is applied and there is no reset pulse. the triggers of these microcircuits can become in an arbitrary state that does not correspond to the allowed state of the counter. However, these microcircuits have a special circuit for forming the allowed state of the counter, and when clock pulses are applied, the counter will switch to normal operation after a few clock cycles. Therefore, in frequency dividers, in which the exact phase of the output signal is not important, it is permissible not to apply initial setting pulses to the R inputs of the K176IE8, K561IE8 and K561IE9 microcircuits.

Microcircuits K176IE8, K561IE8, K561IE9 can be combined into multi-bit counters with sequential transfer, connecting the transfer output P of the previous microcircuit with the CN input of the next one and feeding the CP log to the input. 0. It is also possible to connect an older

decoder output (7 or 9) with the CP input of the next microcircuit and feeding to the CN log input. 1. Such connection methods lead to the accumulation of delays in the multi-bit counter. If it is necessary that the output signals of the multi-bit counter microcircuits change simultaneously, parallel transfer with the introduction of additional NAND elements should be used. In fig. 189 is a schematic diagram of a 3-decadal parallel carry counter. The DD1.1 inverter is only needed to compensate for the delays in the DD1.2 and DD1.3 elements. If a high accuracy of simultaneous switching of the counter decades is not required, the input counting pulses can be applied to the CP input of the DD2 microcircuit without an inverter, and to the CN DD2 input - log.1. The maximum operating frequency of multi-bit counters with both serial and parallel transfer does not decrease relative to the operating frequency of an individual microcircuit.

In fig. 190 shows a fragment of a timer circuit using K176IE8 or K561IE8 microcircuits. At the moment of start-up, counting pulses begin to arrive at the CN input of the DD1 microcircuit. When the counter microcircuits are set to the positions dialed on the switches, a log will appear at all inputs of the NAND DD3 element. 1, element

DD3 will turn on, a log will appear at the output of the DD4 inverter. 1, signaling the end of the time interval.

The K561IE8 and K561IE9 microcircuits are convenient to use in frequency dividers with a switchable division ratio. In fig. 191 shows an example of a 3-decadal frequency divider. The SA1 switch sets the units of the required conversion factor, the SA2 switch - tens, and the SA3 switch - hundreds. When the counters DD1 - DD3 reach the state corresponding to the positions of the switches, a log comes to all inputs of the DD4.1 element. 1. This element turns on and sets the trigger on elements DD4.2 and DD4.3 in a state in which a log appears at the output of element DD4.3. 1, resetting counters DD1 - DD3 to their original state (Fig. 192). As a result, a log also appears at the output of the DD4.1 element. 1 and the next input pulse of negative polarity sets the trigger DD4.2, DD4.3 to its original state, the reset signal from the R inputs of the DD1 - DD3 microcircuits is removed and the counter continues to count.

A trigger on DD4.2 and DD4.3 elements guarantees the reset of all DD1 - DD3 microcircuits when the counter reaches the desired state. In its absence and a large spread in the switching thresholds of microcircuits

DD1 - DD3 at the R inputs, a case is possible when one of the DD1 - DD3 microcircuits is set to 0 and removes the reset signal from the R inputs of the remaining microcircuits before the reset signal reaches their switching threshold. However, such a case is unlikely, and you can usually do without a trigger, more precisely, without the DD4.2 element.

To obtain a conversion factor of less than 10 for the K561IE8 microcircuit and less than 8 for the K561IE9, you can connect the decoder output with a number corresponding to the required conversion factor to the R input of the microcircuit directly, for example, as shown in Fig. 193 (a) for a conversion factor of 6. Time

the operation diagram of this divider is shown in Fig. 193 (6). The carry signal can be removed from the P output only if the conversion factor is 6 or more for K561IE8 and 5 or more for K561IE9. At any ratio, the carry signal can be removed from the output of the decoder with a number one less than the conversion factor.

It is convenient to indicate the state of the counters of the K176IE8 and K561IE8 microcircuits on gas-discharge indicators, coordinating them using keys on high-voltage n-p-n transistors, for example, the P307 - P309, KT604, KT605 series or K166NT1 assemblies (Fig. 194).

Microcircuits K561IE10 and KR1561IE10 (Fig. 195) contain two separate four-bit binary counters, each of which has inputs СР, CN, R. Setting the counter triggers to their initial state occurs when the R log is applied to the input. 1. The logic of the CP and CN inputs is different from the operation of similar inputs of the K561IE8 and K561IE9 microcircuits. The triggers of the K561IE10 and KR561IE10 microcircuits are triggered by the decay of positive-polarity pulses at the input of the SR at log. 0 at the CN input (for K561IE8 and K561IE9, the CN input must be log. 1) It is possible to supply pulses of negative polarity to the CN input, while the CP input must be log 1 (for K561IE8 and K561IE9 - log. 0). Thus, the inputs of CP and CN in the K561IE10 and KR1561IE10 microcircuits are combined according to the circuit of the AND element, in the K561IE8 and K561IE9 microcircuits - OR.

The timing diagram of the operation of one counter of the microcircuit is shown in Fig. 196. When connecting microcircuits to a multi-bit counter with sequential transfer, the outputs of 8 previous counters are connected to the CP inputs of the subsequent ones, and a log is fed to the CN inputs. 0 (fig. 197). If it is necessary to provide parallel transfer, additional NAND and NOR additional elements should be installed. In fig. 198 shows a schematic diagram of a parallel carry counter. The passage of the counting pulse to the input of the CP of the DD2.2 counter through the DD1.2 element is allowed when the DD2.1 counter is in the 1111 state, when the output of the DD3.1 element is log. 0. Similarly, the passage of the counting pulse to the input of the CP DD4.1 is possible only in the state of 1111 counters DD2.1 and DD2.2, etc. The purpose of the DD1.1 element is the same as DD1.1 in the diagram of Fig. 189, and it can be excluded under the same conditions. The maximum input pulse frequency is the same for both meter versions, but in a parallel transfer meter, all output signals are switched simultaneously.

One microcircuit counter can be used to construct frequency dividers with a division factor from 2 to 16. For example, in fig. 199 shows a diagram of a counter with a conversion factor 10 To obtain the conversion factors -, 5,6,9,12, you can use the same scheme by appropriately selecting the counter outputs to connect to the DD2.1 inputs. To obtain the conversion factors 7, 11, 13, l4 element DD2.1 must have three inputs, for coefficient 15 - four inputs.

The K561IE11 microcircuit is a binary four-digit reverse counter with the possibility of parallel information recording (Fig. 200). The microcircuit has four information outputs 1, 2, 4,8, transfer output P and the following inputs: transfer input PI, input for setting the initial state R, input for supplying counting pulses C, input for counting direction U, inputs for supplying information during parallel recording Dl - D8, parallel recording input S.

Input R has priority over other inputs: if you submit a log to it. 1, outputs 1, 2, 4, 8 will be logic 0 regardless of the state

other inputs. If at the input R log. 0, input S has priority. When log. 1, asynchronous recording of information from inputs D1-D8 to counter triggers occurs.

If the inputs R, S, PI log. 0, the microcircuit is allowed to work in counting mode. If at the entrance U log. 1, for each fall of the input pulse of negative polarity arriving at input C, the state of the counter will increase by one. When log. 0 at input U counter is switched

In the subtraction mode - for each fall of the pulse of negative polarity at the input C, the counter state decreases by one. If you submit a log to the PI transfer input. 1, the counting mode is prohibited.

At the output of the transfer P log. 0, if at the input PI log. 0 and all counter triggers are in state 1 when counting up or state 0 when counting down.

To connect the microcircuits to a counter with a sequential transfer, it is necessary to combine all the C inputs, the outputs of the P microcircuits must be connected to the PI inputs of the following ones, and a log must be applied to the PI input of the least significant bit. 0 (fig. 201). The output signals of all microcircuits of the counter change simultaneously, however, the maximum operating frequency of the counter is less than that of a single microcircuit due to the accumulation of delays in the transfer circuit. To ensure the maximum operating frequency of the multi-digit counter, it is necessary to provide a parallel transfer, for which a log should be applied to the PI inputs of all microcircuits. Oh, and the signals to the inputs C of the microcircuits are fed through additional OR elements, as shown in Fig. 202. In this case, the passage of the counting pulse to the inputs of the C microcircuits will be allowed only when the P outputs of all previous microcircuits log. 0,

Moreover, the delay time of this resolution after the simultaneous actuation of microcircuits does not depend on the number of counter bits.

The peculiarities of the construction of the K561IE11 microcircuit require that the change in the signal of the counting direction at the input U take place in a pause between the counting pulses at the input C, that is, at log. 1 at this input, or on the decay of this pulse.

The K176IE12 microcircuit is intended for use in electronic watches (Fig. 203). It includes a quartz generator G with an external quartz resonator at a frequency of 32768 Hz and two frequency dividers: ST2 at 32768 and ST60 at 60. When a quartz resonator is connected to the microcircuit according to the scheme in Fig. 203 (b), it provides frequencies of 32768, 1024, 128, 2, 1, 1/60 Hz. Pulses with a frequency of 128 Hz are formed at the outputs of the T1 - T4 microcircuit, their duty cycle is 4, they are shifted among themselves by a quarter of a period. These pulses are intended for switching the familiarity of the clock indicator with dynamic indication. Pulses with a frequency of 1/60 Hz are fed to the minute counter, pulses with a frequency of 1 Hz can be used to feed the seconds counter and to ensure the dividing point flashes, pulses with a frequency of 2 Hz can be used to set the clock. The frequency of 1024 Hz is intended for the sound signal of the alarm clock and for interrogating the digits of the counters with dynamic indication, the frequency output of 32768 Hz is the control one. The phase relationships of oscillations of various frequencies with respect to the moment when the reset signal is removed are shown in Fig. 204, the time scales of the various charts in this figure are different. Using

pulses from outputs T1 - T4 for other purposes, pay attention to the presence of short false pulses at these outputs.

A feature of the microcircuit is that the first drop at the output of minute impulses M appears 59 s after removing the setting signal 0 from input R. This forces the button that generates the setting signal 0 to be released when starting the clock, one second after the sixth time signal. The edges and slopes of the signals at the output M are synchronous with the slopes of the pulses of negative polarity at the input C.

The resistance of the resistor R1 can have the same value as for the K176IE5 microcircuit. Capacitor C2 is used for fine tuning the frequency, C- for coarse. In most cases, the capacitor C4 can be eliminated.

The K176IE13 microcircuit is designed to build an electronic clock with an alarm clock. It contains counters of minutes and hours, a memory register for an alarm clock, a circuit for comparing and issuing a sound signal, a circuit for dynamically issuing codes for numbers for supplying indicators. Usually the K176IE13 chip is used in conjunction with the K176IE12. The standard connection of these microcircuits is shown in Fig. 205. The main output signals of the circuit fig. 205 are pulses T1 - T4 and the codes of the numbers at the outputs 1, 2, 4, 8. At times when the output T1 log. 1, at outputs 1,2,4,8 there is a code for the digit of units of minutes, when the log. 1 at output T2 - code for tens of minutes, etc. At output S - pulses with a frequency of 1 Hz for ignition of the dividing point. The pulses at the output C serve to strobe the writing of the digit codes into the memory register of the K176ID2 or K176ID- microcircuits, usually used in conjunction with the K176IE12 and K176IE13, the pulse at the K output can be used to dim the indicators during the clock correction. The extinguishing of indicators is necessary, since at the moment of correction, the dynamic indication stops and in the absence of extinguishing, only one discharge glows with a brightness increased four times.

Output HS - alarm clock output. The use of outputs S, K, HS is optional. Submission of log. 0 to the V input of the microcircuit translates its outputs 1, 2, 4, 8 and C into a high-impedance state.

When power is applied to the microcircuits, zeros are automatically written to the hour and minute counter and the alarm clock memory register. To enter the initial reading into the minute counter, press

button SB1, the counter readings will start to change with a frequency of 2 Hz from 00 to 59 and then again 00, at the moment of transition from 59 to 00 the hour counter readings will increase by one. The hour counter will also change at a frequency of 2 Hz from 00 to 23 and again 00 if you press the SB2 button. If you press the SB3 button, the indicators will show the alarm time. When the SB1 and SB3 buttons are pressed simultaneously, the indication of the digits of the minutes of the alarm activation time will change from 00 to 59 and again 00, but the transfer to the clock digits does not occur. If you press the SB2 and SB3 buttons, the indication of the digits of the hours of the alarm clock activation time will change, upon transition from the state 23 to 00, the indications of the digits of minutes will be reset. You can press three buttons at once, in this case, the readings of both the minutes and hours will change.

The SB4 button is used to start the clock and correct the stroke during operation. If you press the SB4 button and release it one second after the sixth time signal, the correct reading and the exact phase of the minute counter will be established. Now you can set the hour counter by pressing the SB2 button, while the minute counter will not be disturbed. If the minute counter is between 00 ... 39, the hour counter will not change when you press and release the SB4 button. If the minutes counter is within 40 ... 59, after releasing the SB4 button, the hour counter increases by one. Thus, to correct the course of the clock, regardless of whether the clock was late or in a hurry, it is enough to press the SB4 button and release it a second after the sixth time signal.

The standard scheme for turning on the time setting buttons has the disadvantage that if you accidentally press the SB1 or SB2 buttons, the clock fails. If the circuit in Fig. 205 add one diode and one button (Fig. 206), the clock can be changed only by pressing two buttons at once - the SB5 button ("Set

ka ") and the SB1 or SB2 button, which is much less likely to be accidentally done.

If the readings of the clock and the time for turning on the alarm clock do not match, at the output of the HS chip of the K176IE13 log. 0. If the readings coincide at the HS output, pulses of positive polarity appear with a frequency of 128 Hz and a duration of 488 μs (duty cycle 16). When they are sent through the emitter follower to any emitter, the signal resembles the sound of a conventional mechanical alarm clock. The signal stops when the clock and alarm clock no longer match.

The matching scheme for the outputs of the K176IE12 and K176IE13 microcircuits with indicators depends on their type. For example, in Fig. 207 shows a diagram for connecting semiconductor seven-segment indicators with a common anode. Both cathode (VT12 - VT18) and anode (VT6, VT7, VT9, VT10) switches are made according to the emitter follower circuits. Resistors R4 - R10 determine the pulse current through the segments of the indicators.

Shown in fig. 207, the value of the resistances of the resistors R4-R10 provides a pulse current through the segment of approximately 36 mA, which corresponds to an average current of 9 mA. With this current, the AL305A, ALS321B, ALS324B indicators and others have a fairly bright glow. The maximum collector current of transistors VT12 - VT18 corresponds to the current of one segment of 36 mA, and therefore, here you can use almost any low-power transistors pnp with a permissible collector current of 36 mA or more.

The impulse currents of the transistors of the anode switches can reach 7 x 36 - 252 mA, therefore, transistors that allow the specified current can be used as anode switches, with a base current transfer coefficient h21e of at least 120 (series KT3117, KT503, KT815).

If transistors with such a coefficient cannot be selected, you can use composite transistors (KT315 + KT503 or KT315 + KT502). Transistor VT8 - any low-power, npn structure.

Transistors VT5 and VT11 are emitter repeaters for connecting the HA1 alarm clock sound emitter, as which you can use any phones, including small ones from hearing aids, any dynamic heads connected through an output transformer from any radio receiver. By selecting the capacitance of the capacitor C1, you can achieve the required signal volume, you can also set a variable resistor 200 ... 680 Ohm by turning it on with a potentiometer between C1 and HA1. The SA6 switch is used to turn off the alarm.

If indicators with a common cathode are used, the emitter followers connected to the outputs of the DD3 microcircuit should be performed on n-p-n transistors (KT315 series, etc.), and the S DD3 input should be connected to a common wire. For supplying pulses to the cathodes. indicators should collect keys on n-p-n transistors according to the scheme with a common emitter. Their bases should be connected to the outputs T1 - T4 of the DD1 microcircuit through 3.3 kΩ resistors. The requirements for transistors are the same as for transistors of anode switches in the case of indicators with a common anode.

Indication is also possible with luminescent indicators. In this case, it is necessary to supply pulses T1 - T4 to the indicator grids and connect the connected indicator anodes of the same name through the K176ID2 or K176ID- microcircuit to the outputs 1, 2, 4, 8 of the K176IE13 microcircuit.

The scheme for supplying pulses to the indicator grids is shown in Fig. 208. Grids C1, C2, C4, C5 - respectively, the grid of familiarity of units and tens of minutes, units and tens of hours, C- - the grid of the dividing point. The anodes of the indicators should be connected to the outputs of the K176ID2 microcircuit connected to DD2 in accordance with the inclusion of DD3 in Fig. 207 using keys similar to those in fig. 178 (b), 179.180, a log should be fed to the S input of the K176ID2 microcircuit. 1.

It is possible to use the K176ID microcircuit without keys, its input S must be connected to the common wire. In any case, the anodes and grids of the indicators must be connected through 22 ... 100 kΩ resistors to a negative voltage source, which in absolute value is 5 ... 10 V greater than the negative voltage supplied to the cathodes of the indicators. The diagram in Fig. 208 are resistors R8 - R12 and a voltage of -27 V.

It is convenient to supply pulses T1 - T4 to the indicator grids using the K161KN2 microcircuit, applying a supply voltage to it in accordance with Fig. 180.

As indicators can be used any single vacuum fluorescent indicators, as well as flat four-position indicators with dividing points IVL1 - 7/5 and IVL2 - 7/5, specially designed for watches. As a DD4 circuit, Fig. 208, any inverting logic gates with combined inputs can be used.

In fig. 209 shows a diagram of matching with gas-discharge indicators. Anode switches can be made on transistors of the KT604 or KT605 series, as well as on transistors of the K166NT1 assemblies.

The HG5 neon lamp is used to indicate the dividing point. The indicators cathodes of the same name should be combined and connected to the outputs of the DD7 decoder. To simplify the circuit, you can exclude the DD4 inverter, which extinguishes the indicators for the time the correction button is pressed.

The ability to transfer the outputs of the K176IE13 microcircuit to a high-impedance state allows you to build a clock with two readings (for example, MSK and GMT) and two alarms, one of which can be used to turn on a device, the other to turn it off (Fig. 210).

The inputs of the same name of the main DD2 and additional DD2 of the K176IE13 microcircuits are connected to each other and to other elements according to the scheme in Fig. 205 (you can take into account Fig. 206), except for inputs P and V. In the upper position of the switch SA1 according to the scheme, the signals

settings from the buttons SB1 - SB3 can be fed to the input P of the DD2 chip, in the lower one - to DD2. The signal supply to the DD3 microcircuit is controlled by the switch section SA1.2. In the upper position of the switch SA1 log. 1 is fed to the V input of the DD2 microcircuit and signals from the DD2 outputs pass to the DD3 inputs. In the lower position of the switch log. 1 at the V input of the DD2 chip allows the transmission of signals from its outputs.

As a result, when the switch SA1 is in the upper position, it is possible to control the first clock and alarm clock and indicate their state, in the lower position - to the second.

The activation of the first alarm clock turns on the trigger DD4.1, DD4.2, a log appears at the output of DD4.2. 1, which can be used to turn on a device, a second alarm will turn off that device. The SB5 and SB6 buttons can also be used to turn it on and off.

When using two K176IE13 microcircuits, the reset signal to the R input of the DD1 microcircuit should be taken directly from the SB4 button. In this case, the correction of the readings occurs as shown in Fig. 205 connection, but blocking the SB4 button "Corr."

when you press the SB3 "Bud." (Fig. 205) existing in the standard version does not occur. When the SB3 and SB4 buttons are pressed simultaneously in a watch with two K176IE13 microcircuits, the readings fail, but not the clock. The correct readings are restored if you press the SB4 button again with the SB3 released.

Chip K561IE14 - binary and binary decimal four-digit decimal counter (fig. 211). Its difference from the K561IE11 microcircuit consists in replacing input R with input B - the input for switching the counting module. When log. 1 at the input B, the K561IE14 chip produces a binary count, just like the K561IE11, with a log. 0 at input B is BCD. The purpose of the remaining inputs, operating modes and switching rules for this microcircuit are the same as for the K561IE11.

Microcircuit KA561IE15 is a frequency divider with a switchable division ratio (Fig. 212). The microcircuit has four control inputs Kl, K2, K-, L, an input for supplying clock pulses C, sixteen inputs for setting the division factor 1-8000 and one output.

The microcircuit allows you to have several options for setting the division ratio, the range of its change is from 3 to 21327. -the simplest and most convenient option will be considered here, for which, however, the maximum possible division ratio is 16659. For this option, the input K- should be constantly applied log. 0.

Input K2 is used to set the initial state of the counter, which occurs in three periods of input pulses when a log is applied to the input K2. 0. After submitting the log. 1 to input K2, the counter starts operating in the frequency division mode. Frequency division ratio when feeding log. 0 to inputs L and K1 is equal to 10000 and does not depend on the signals applied to inputs 1-8000. If different input signals are applied to inputs L and K1 (log.0 and log. 1 or log. 1 and log. 0), the frequency division factor of the input pulses will be determined by the binary-decimal code applied to inputs 1-8000. For example, in Fig. 213 shows a timing diagram of the operation of the microcircuit in the division by 5 mode, to ensure which a log should be applied to inputs 1 and 4. 1, to inputs 2, 8-8000 - log. 0 (K1 is not equal to L).

The duration of the output pulses of positive polarity is equal to the period of the input pulses, the rising and falling edges of the output pulses coincide with the falling edges of the input pulses of negative polarity.

As can be seen from the timing diagram, the first pulse at the output of the microcircuit appears on the decay of the input pulse with a number greater by one than the division factor.

When submitting a log. 1 to inputs L and K1, the single counting mode is carried out. When applying to the input K2 log. 0, a log appears at the output of the microcircuit. 0. The pulse duration of the initial setting at the input K2 must be, as in the frequency division mode, at least three periods of the input pulses. After the end of the initial setting pulse at the input K2, the counting will begin, which will occur according to the slopes of the input pulses of negative polarity. After the end of the pulse with a number, one greater than the code set at inputs 1-8000, log. 0 at the output will change to log. 1, after which it will not change (Fig. 213, K1 - L - 1). For the next start, it is necessary to re-send the initial setting pulse to the input K2.

This mode of operation of the microcircuit is similar to the operation of a waiting multivibrator with a digital setting of the pulse duration, one should only remember that the duration of the input pulse includes the duration of the initial setting pulse and, moreover, another period of the input pulses.

If, after the end of the formation of the output signal in the single-shot mode, send a log to the input K1. 0, the microcircuit will enter the input frequency division mode, and the phase of the output pulses will be determined by the initial setting pulse, which was given earlier in the single-shot mode. As already mentioned above, the microcircuit can provide a fixed frequency division ratio equal to 10,000 if a log is applied to the inputs L and K1. 0. However, after the initial setting pulse applied to input K2, the first output pulse appears after a pulse with a number greater than the code set at inputs 1-8000 is applied to input C. All subsequent output pulses will appear 10,000 input pulse cycles after the start of the previous one.

At inputs 1-8, permissible combinations of input signals must correspond to the binary equivalent of decimal numbers from 0 to 9. At inputs 10-8000, arbitrary combinations are allowed, that is, it is possible to supply numbers from 0 to 15 for each decade. As a result, the maximum possible division factor K will be:

K - 15000 + 1500 + 150 + 9 \u003d 16659.

The microcircuit can be used in frequency synthesizers, electronic musical instruments, programmable time relays, to form precise time intervals in the operation of various devices.

The K561IE16 microcircuit is a fourteen-bit binary counter with sequential transfer (Fig. 214). The microcircuit has two inputs - the input for setting the initial state R and the input for supplying clock pulses C. The counter triggers are set to 0 when the log is applied to the R input. 1, counting - by the slopes of positive-polarity pulses supplied to input C.

The counter does not have outputs of all digits - there are no outputs of digits 21 and 22, therefore, if it is necessary to have signals from all binary digits of the counter, you should use another counter that operates synchronously and has outputs 1, 2, 4, 8, for example, half of the K561IE10 microcircuit ( fig. 215).

The division factor of one K561IE16 microcircuit is 214 \u003d 16384, if it is necessary to obtain a larger division factor, the output of the 213 microcircuit can be connected to the input of another such microcircuit or to the CP input of any other microcircuit - a counter. If the input of the second K561IE16 microcircuit is connected to the 2 ^ 10 output of the previous one, it is possible to obtain the missing outputs of two bits of the second microcircuit by reducing the counter capacity (Fig. 216). By connecting half of the K561IE10 microcircuit to the input of the K561IE16 microcircuit, you can not only get the missing outputs, but also increase the counter capacity by one (Fig. 217) and provide a division factor of 215 \u003d 32768.

The K561IE16 microcircuit is conveniently used in frequency dividers with a tunable division ratio according to a scheme similar to Fig. 199. In this scheme, the DD2.1 element must have as many inputs as there are ones in the binary representation of the number that determines the required division ratio. For example, in Fig. 218 shows a diagram of a frequency divider with a conversion factor of 10000. The binary equivalent of a decimal number 10000 is 10011100010000, an AND element is required for five inputs, which must be connected to the outputs 2 ^ 4 \u003d 16.2 ^ 8 \u003d 256.2 ^ 9 \u003d 512.2 ^ 10 \u003d 1024 and 2 ^ 13 \u003d 8192. If connection to outputs 2 ^ 2 or 2 ^ 3 is required, use the diagram in fig. 215 or 59, with a coefficient of more than 16384 - the diagram in Fig. 216.

To convert a number to binary form, divide it entirely by 2, write the remainder (0 or 1). Divide the result by 2 again, write the remainder, and so on, until there is zero after the division. The first remainder is the least significant bit of the binary form of the number, the last is the most significant.

Chip K176IE17 - calendar. It contains counters for days of the week, numbers of the month and months. The counter of numbers counts from 1 to 29, 30 or 31 depending on the month. The days of the week are counted from 1 to 7, months are counted from 1 to 12. The diagram for connecting the K176IE17 microcircuit to the K176IE13 clock microcircuit is shown in Fig. 219. At outputs 1-8 of the DD2 microcircuit there are alternately the codes of the digits of the day and month, similar to the codes of the hours and minutes at the outputs

microcircuits K176IE13. The indicators are connected to the specified outputs of the K176IE17 microcircuit in the same way as they are connected to the outputs of the K176IE13 microcircuit using write pulses from the C output of the K176IE13 microcircuit.

At outputs A, B, C there is always a code 1-2-4 of the serial number of the day of the week. It can be fed to the K176ID2 or K176ID- microcircuit and then to any seven-segment indicator, as a result of which the number of the day of the week will be indicated on it. However, more interesting is the possibility of displaying the two-letter designation of the day of the week on the alphanumeric indicators IV-4 or IV-17, for which it is necessary to make a special code converter.

Setting the date, month and day of the week is done in the same way as setting the readings in the K176IE13 microcircuit. When you press the SB1 button, the day is set, the SB2 button - the month, when SB3 and SB1 are pressed together - the day of the week. To reduce overall

the number of buttons in a watch with a calendar, you can use the buttons SB1 -SB3, SB5 of the diagram fig. 206 for setting the calendar readings, switching their common point with a toggle switch from input P of the K176IE13 microcircuit to the P input of the K176IE17 microcircuit. For each of these microcircuits, the R1C1 circuit must have its own, like the circuit in Fig. 210.

Submission of log. 0 to the V input of the microcircuit translates its outputs 1-8 into a high-impedance state. This feature of the microcircuit makes it relatively easy to organize alternate output of clock and calendar readings on one four-digit indicator (except for the day of the week). Scheme
connecting the K176ID2 (ID-3) microcircuit to the IE13 and IE17 microcircuits to ensure the specified mode is shown in Fig. 220, the connection circuits of the K176IE13, IE17 and IE12 microcircuits are not shown among themselves. In the upper position of the switch SA1 ("Clock"), outputs 1-8 of the DD3 microcircuit are in a high-impedance state, the output signals of the DD2 microcircuit through the resistors R4 - R7 are fed to the DD4 microcircuit inputs, the state of the DD2 microcircuit is indicated - hours and minutes. With the lower position of the switch SA1 ("Calendar"), the outputs of the DD3 chip are activated, and now the DD3 chip determines the input signals of the DD4 chip. Transfer the outputs of the DD2 microcircuit to a high-impedance state, as is done in the circuit

fig. 210, it is impossible, since in this case the output C of the DD2 microcircuit will also go into a high-impedance state, and the DD3 microcircuit does not have a similar output. In the diagram in Fig. 220 implements the aforementioned use of one set of buttons for setting the clock and calendar readings. Pulses from the SB1 - SB3 buttons are fed to the P input of the DD2 or DD3 microcircuit, depending on the position of the same switch SA1.

The K176IE18 microcircuit (Fig. 221) is in many ways similar in structure to the K176IE12. Its main difference is the execution of outputs T1 - T4 with an open drain, which makes it possible to connect grids of vacuum fluorescent indicators to this microcircuit without matching switches.

To ensure reliable locking of the indicators along their grids, the duty cycle of pulses T1 - T4 in the K176IE18 microcircuit is made slightly more than four and is 32/7. When submitting a log. 1 to the input R of the microcircuit at the outputs T1 - T4 log. 0, so the supply of a special blanking signal to the K input of the K176ID2 and K176ID3 microcircuits is not required.

Green vacuum fluorescent indicators appear much brighter in the dark than in the light, so it is desirable to be able to change the brightness of the indicator. Micro-circuit K176IE18 has an input Q, giving a log. 1 to this input, you can increase the duty cycle of the pulses at the outputs T1 - T4 and in

decrease the brightness of the indicators by the same number of times. The signal to the Q input can be applied either from the brightness switch, or from the photoresistor, the second terminal of which is connected to the positive power supply. In this case, input Q should be connected to the common wire through a 100 k0m ... 1 MΩ resistor, which must be selected to obtain the required ambient light threshold, at which the brightness will automatically switch.

It should be noted that when log. 1 at input Q (low brightness), the clock setting has no effect.

The K176IE18 microcircuit has a special sound signal generator. When a pulse of positive polarity is applied to the HS input, packets of negative polarity pulses with a frequency of 2048 Hz and a duty cycle appear at the HS output. The duration of the packs is 0.5 s, the repetition period is 1 s. The HS output is made with an open drain and allows you to connect emitters with a resistance of 50 Ohm or higher between this output and the positive power supply without an emitter follower. The signal is present at the HS output until the end of the next minute pulse at the M output of the microcircuit.

It should be noted that the permissible output current of the K176IE18 microcircuit at the T1 - T4 outputs is 12 mA, which significantly exceeds the current of the K176IE12 microcircuit, therefore the requirements for the gain of transistors in the keys when using the K176IE18 microcircuits and semiconductor indicators (Fig. 207) are much less stringent, enough h21e\u003e 20. Basic resistance

The resistors in the cathode switches can be reduced to 510 Ohm at h21e\u003e 20 or to 1k0m at h21e\u003e 40.

Microcircuits K176IE12, K176IE13, K176IE17, K176IB18 allow the supply voltage is the same as the microcircuits of the K561 series - from 3 to 15 V.

The K561IE19 microcircuit is a five-bit shift register with the possibility of parallel recording of information, intended for building counters with a programmable counting module (Fig. 222). The microcircuit has five information inputs for parallel recording D1 -D5, information input for sequential recording DO, parallel recording input S, reset input R, input for supplying clock pulses C and five inverse outputs 1-5.

Input R is predominant - when logging to it. 1 all Triggers of the microcircuit are set to 0, a log appears on all outputs. 1 regardless of the signals at the other inputs. When applied to the input R log. 0, to the input S log. 1, information is written from inputs D1 - D5 to the triggers of the microcircuit, at outputs 1-5 it appears in inverse form.

When applied to inputs R and S log. 0, information can be shifted in the microcircuit triggers, which will occur according to the drops of pulses of negative polarity arriving at input C. In the first trigger, information will be recorded from input D0.

If you connect the DO input to one of the outputs 1-5, you can get a counter with a conversion factor of 2, 4, 6, 8, 10. For example, in fig. 223 shows the timing diagram of the operation of the microcircuit in the division by 6 mode, which is organized when the input D0 is connected to the output 3. If you need to get an odd conversion factor of 3.5.7 or 9, you should use a two-input AND element, the inputs of which are connected to outputs 1, respectively and 2, 2 and 3, 3 and 4,4 and 5, the output is to the DO input. For example, in Fig. 224 shows a diagram of a frequency divider by 5, in Fig. 225 is a timing diagram of its operation.

It should be borne in mind that the use of the K561IE19 microcircuit as a shift register is impossible, since it contains correction circuits, as a result of which the combinations of trigger states that are not working for the counting mode are automatically corrected. The presence of correction chains allows

Similar to the use of K561IE8 and K561IE9 microcircuits, do not apply an initial setting pulse to the counter if the phase of the output pulses is not important.

The KR1561IE20 microcircuit (Fig. 226) is a twelve-bit binary counter with division factors 2 ^ 12 \u003d 4096. It has two inputs - R (for setting the zero state) and C (for supplying clock pulses). When log. 1 at input R, the counter is set to zero, and when log. 0 - counts by the slopes of pulses of positive polarity arriving at input C. The microcircuit can be used to divide the frequency into coefficients that are a power of the number 2. To build dividers with a different division factor, you can use the circuit to turn on the K561IE16 microcircuit (Fig. 218).

Microcircuit KR1561IE21 (Fig. 227) is a synchronous binary counter with the possibility of parallel recording of information on the decay of the clock pulse. The microcircuit functions similarly to the K555IE10 (Fig. 38).