SU1737714A1 - Controlled frequency divider - Google Patents

Abstract

The invention relates to a pulse technique. The purpose of the invention is to increase the reliability of the device by simplifying. The device contains a subtractive pulse counter 1, a one-shot 2, an analog-code converter 3, a first control bus 4, an input bus 5, an output bus 6, and a second control bus 7 with corresponding connections. The single-oscillator contains a pulse counter, a code-analog converter and a comparator with corresponding connections. 1 hp f-ly, 2 ill.

Description

with

with

FIG.

Xi

with

Xi xi

The invention relates to a pulse technique. It can be used in automation, computing and measuring technology.

A controlled frequency divider is known that contains a subtracting pulse counter to a one-shot.

A disadvantage of the known device is its low reliability due to the use of a large number of blocks and the connections between them.

The purpose of the invention is to increase the reliability of the device (I) by simplifying.

The goal is achieved by controlling a frequency divider containing a reading pulse counter, the saeva output of which is connected to the one-channel input, an analog-to-analog converter, the input of which is connected to the first control bus and the outputs connected to the information inputs of the deactivating pulse counter, The counting input of which is connected to the input bus, the recording input is connected to the output bus and the output of a single driver, the control input of which is connected to the second control bus.

In addition, in order to maintain the duty ratio when the input frequency changes, the single-oscillator contains a counter, the input si «: the ionization of which is connected to the input of one to the speaker, the input of the zero setting - to the input bus of the device, the information inputs are connected to the outputs of the code converter the analogue, the output of which is connected to the first input of the comparator, the second input — to the control input of the single-vibrator, and the output — to the output of the one-vibrator.

FIG. 1 shows a frequency divider circuit; in fig. 2 shows an example of the execution of a controlled odvovibrator.

The frequency divider (Fig. 1) contains a subtracting counter i pulses, a one-shot 2, an analog-code converter 3, the input of which is connected to the first control bus 4, and the outputs to information inputs of the counter 1 and the counting input of which is connected to the input bus 5, the recording input is with the output bus 6 and the one-shot output, and the loan output is with the one-input input, the control input of which is connected to the second control bus 7.

The controlled one-shot (Fig. 2) contains a counter 8, whose synchronization input is connected to the one-shot input, the zero setting input is connected to the device input bus 5, the information outputs are connected to the inputs of the converter 9, an analogue code whose output is connected to the first comparator input 10, second entrance - from

the control input 7 of the one-shot, and the output - with the output 6 of the one-shot 2.

The controlled frequency divider operates as follows.

Description started from time ti

the formation of a zero voltage level from the output of the borrowing of the counter 1, thus forming the rear edge of the output pulse on the bus 6 (the one-shot is made

0 such that, in its initial state, there is a high voltage at its output, and the launch of the one-shot is carried out by a voltage drop from high to low; after starting one-shot, the voltage on it

5 output becomes close to zero during the entire time the output pulse is formed). After the time ti occurs at the entry of the recording, the installation of the counter 1 in the state, which is determined by the code of the generator 3 analog-code. This state is held until time t.2 - the return of the one-shot 2 to the initial state, at which a high voltage is generated at its output, which

5 is enabling for counting the pulses of counter 1. Starting from time point v.2, the code of counter 1 decreases by one with the arrival of each input pulse Ubx on bus 5. After a time Ta of duration

0 output pulse code in counter 1 becomes equal to zero, at the output of the loan the voltage becomes equal to zero (time ts). A one-vibration 2 starts up and the output voltage becomes

5 equals zero. Counter 1 is set to the state determined by a code from the output of the converter 3 analog-code, and the last time the interval pp between pulses begins again the counting time by the counter

0 1, etc.

Changing the voltage on the first control bus 4, changing the code from the output of the converter 3 analog-code and thereby changing the duration of the output pulse, i.e. time Td changing the voltage on the control input 7 of the single-oscillator, changing the pause between the output pulses .

The division factor of the input frequency is determined by the ratio of the period of the output pulses to the period of the input pulses.

The proposed frequency divider allows you to set a constant output pulse duration when adjusting the division factor or the same

5 pauses between output pulses when adjusting the division factor of the frequency divider. In the case of short set times, the duration of the output pulses or the pause between them, the division factor

the controlled frequency divider is proportional to the input voltage, i.e., for example, by doubling the control voltage, the division factor also doubles. This is an additional advantage of the proposed technical solution.

 The single-vibration 2 can be performed both analog and using digital technology (for example, the circuit in Fig. 2). The latter provides greater accuracy in controlling the division factor and allows to obtain a constant output ratio of the output pulses when the input frequency changes,

One-shot (Fig. 2) works as follows

In the initial state at its output (bus 6), a high voltage. At the moment of arrival of the one-shot impulse, the counter 8 is set to zero, the voltage at the output of the converter 9 is equivalent to zero, the attacks as a non-inverted input of the comparator 10 from the bus 7 are supplied with a positive voltage, the voltage at the comparator 10 becomes equal to to zero. With the end of the input impulse of the one-shot, the counter code begins to increase with the arrival of each input pulse to the bus 5, the voltage at the output of the converter 9 the code-equivalent increases. Through time Tp, the voltage value from the output

The code-analog converter 9 exceeds the voltage on the control bus 7 and a high voltage is generated at the output of the comparator 10.

Claims (2)

1. A controlled frequency divider comprising a subtractive pulse counter, the borrowing output of which is connected to the one-shot input, characterized in that, in order to increase the reliability of the frequency divider, an analog-code converter has been entered into it, the input of which is connected to the first control bus, and the outputs are connected to information inputs of a subtractive pulse counter, the counting input of which is connected to the input bus, the write input is connected to the output bus and an one-shot output, the control input of which is connected to the second control bus. 2. The frequency divider according to claim 1, that is, so that, in order to maintain the duty cycle when the input frequency changes, the One-Vibrator contains a pulse counter, the synchronization input of which is connected with the one-shot input, the zero-setting input — with the frequency splitter input bus, the information outputs are connected to the code-analogue converter inputs, the output of which is connected to the first input of the comparator, the output of which is connected to the one-shot output, and the second input to the one-shot control input.