SU738142A1 - Frequency-to-voltage converter - Google Patents

Description

(54) VOLTAGE FREQUENCY CONVERTER

one

The invention relates to the field of measurement technology, namely to devices for converting frequency to voltage.

A frequency to voltage converter is known, which contains a frequency converter into a code made according to the principle of filling the reference time interval with frequency-converted pulses and a code-analog converter 1. Its disadvantage is low speed.

The prototype of the invention is a frequency to voltage converter that contains a short pulse shaper, whose input is connected to the converter input, a reference frequency generator, the output of which is connected to the first inputs of the AND gate, a pulse counter whose input is connected to the output of the AND gate, and outputs to the first inputs of logical elements AND rewriting, the register whose inputs are connected to the outputs of logical elements AND rewriting, and the outputs to the inputs of the code-analogue converter and the connected serial The first and second one-shot ones. In this case, the input of the first one-shot is connected to the input of the converter, the output of the second one-shot, the torus is connected to the control input of the pulse counter J, the output of both one-shot is connected to the inputs of the OR logic element, the output of which is connected to the second input of the AND 2.

A disadvantage of the known transducer is the presence of a graft associated with the instability of the duration of the pulses of one-shot.

The purpose of the invention is to improve the accuracy of the transformation.

15

The goal is achieved by the fact that in a known frequency to voltage converter containing a short pulse shaper, the input

20 of which is connected to the converter input, the generator of the reference frequency, the output of which is connected to the first IU of pen1eV6 6 lHGYChichesky element I, the pulse counter, the input of which is connected to the output of the first logical element I, and the output {to the (first inputs of logical elements And rewriting, register whose input is connected to the outputs of logic elements AND rewriting, and the outputs - to

738142

The code inputs are entered into the first trigger, the first input of which is connected to the output of the Short pulse shaper, and the first output to the second input of the first logical element And, the second trigger, second logical element And, the first input of which is connected to the output of the reference frequency generator , the second input to the first output of the second trigger, the third input to the second output, the first trigger move, and the output to the second inputs of the logical elements AND rewriting, and the third logical element I, the first input of which is connected to the output the reference frequency generator, the second input to the second output of the first trigger, the third input to the second output of the second trigger, and the output to the control input of the counter. When This, the first input of the second trigger is connected to the output of the second logic element And, the second inputs of the first and second triggers - to the output of the third logic element and.

The drawing shows the functional diagram of the Converter.

The device contains a driver

1 short square impulses, first trigger 2, second trigger 3, reference frequency generator 4, first logic element AND 5, second logic element AND b, third logic element And 7, logic elements AND 8 rewriting, counter 9 pulses, register 10, converter 11 analogue code

The output of the second logic element And 6 is connected to the logical elements And 8 rewriting and the first input of the trigger 3, the output of the third logic element And 7 - with the control input of the counter 9 and the second inputs of the triggers 2 and 3, the Peov input of the trigger 2 is connected to the output of the ramp 1, its outputs - with the inputs of logic elements And 5, 6 and 7, the outputs of the trigger 3 - with the inputs of logic elements And 6 and 7. The new inputs of the logic elements And 5, b and 7 are, 4 are connected to the generator of the reference frequency, and the output of the logic element And 5 is connected to 1Г Bxolcy counter 9-. The outputs of logic elements And 8 rewriting through the register Yu is connected to the converter 11 code-analogue.

The converter works by the following pattern.

The signal of the converted frequency is fed to the driver 1 short-wave pulses. From the driver, the pulses arrive at trigger 2. With the arrival of the next pulse from the driver, which characterizes the end of the previous (measured) period and the beginning of the next period, the trigger

2 start ai a liv ae ts if it’s about, when you go out: Ma

lame elemett And 5 comes

the signal preventing the passage of pulses from the output of the generator 4 of the reference frequency to the input of counter 9,

The code recorded in the counter 9 is the result of the measurement of the previous period and is fed to the logical elements And 8 rewriting. From the second output of trigger 2, a signal is sent to the logic element Ib, allowing it to function, and to the logic element AND 7, preparing it for operation under the action of generator 4 pulses, the first generator pulse 4, after discontinuing the operation of counter 9, through a logic element And 6 enters the logical elements And 8 rewriting and transfers the contents of counter 9 to register 10, erasing the previously recorded number in the register.

From the output of register 10, the code is fed to a converter 11 of a code equivalent, where it is converted into a voltage proportional to the code. The same impulse translates the trigger 3 D state, in which, from its first output, the signal And b receives a signal that prevents the generator 4 pulses from passing through it.

From the second output of the trigger 3 passes a signal to the logical element And 7, allowing its operation

The second impulse of the generator 4, the logic element And 7 arrives at the counter 9 and sets it with the code corresponding to the number two. The same impulse transfers the triggers 2 and., 3 to the initial state. The logical element And 5 receives a signal allowing the passage of the pulses of the generator 4 to the counter 9, which accumulates them before the arrival of the next successive pulse from the driver 1, corresponding to the end of the previous period of the input signal and the beginning of the next period. When a pulse arrives from the driver 1 at the input of trigger 2, the trigger reverses its state to the opposite and the cycle of operation of the device repeats.

Due to its distinctive features, the time during which the initial setting of the pulse counter and the census of its state in the register takes place is equal to two periods of the reference frequency and does not depend on the duration of the pulses of one-shot. Thanks to this, the conversion accuracy is improved.

Claims (1)

Invention Formula The converter, frequency to voltage, contains a short pulse shaper, whose input is connected to the input, a converter, a frequency opsdan generator, the output of which is connected to the first input of the first logic element, And, a pulse counter, the input of which is connected to. the output of the first logical element I, and the outputs to the inputs of the logical elements AND rewriting, the register whose inputs are connected to the outputs of the logic elements AND rewriting, and the outputs to the inputs of the code analogue transformer, characterized in that , the first trigger is entered in it, the first input of which is connected to the output of the short pulse generator, and the first output is connected to the second input of the first logic element And the second trigger, the second logical element I, the first input of which is connected to the output the reference frequency generator, the second input is to the first input of the second trigger, the third input is to the second output of the first trigger, and the output is to the SECOND inputs of logic elements AND overwrites, and the third logic element is And, the first input of which is connected to the output of the reference frequency generator, second the input is to the second output of the first trigger, the third input is to the second output of the second trigger, and the output is to the control input of the counter, the first input of the second trigger is connected to the output of the second logic element I, and the second inputs of the first and second m iggerov connected to the output of the third NAND gate I. Sources of information, Priya Tide into account in the examination 1. Novitsky PV et al. Digital devices with frequency sensors, Energie, 1970, p. 281. 2, USSR Copyright Certificate W 350161, cl. H 03 K 13/20, 12.05.69 (prototype).