SU782143A1 - Pulse repetition frequency-to-voltage converter - Google Patents

Description

I

The invention relates to electrical measuring transducers; in particular, to converters of the period of the pulse following to the voltage and can be used in. automated control and monitoring systems.

A period converter is known to follow a pulse to a voltage containing two storage cells shunted with keys, a linear charge device for storage cells, and an OR element whose inputs are connected to the outputs of storage cells.

Its disadvantage is reduced conversion accuracy.

A known converter of a pulse-to-voltage period to a voltage containing a source of a different polarity reference voltage, an adder and an input trigger, the counting input of which is connected to the input bus of the converter, and the zero and single outputs are connected to the inputs of the first and second channels of a linearly varying voltage each of which contains a counting trigger, an integrator with a constant-aged compensator to the circuit, whose input is connected to a source of a different-pole reference voltage through a switch, ravl yuschy input of which is connected to a unit of a countable output latch, and an inverter having an input pdklyuchoy if the integrator output, wherein the inverter outputs of the integrator and connected through first and second switches respectively to the input of the adder 2.

When diode keys are used in this device, it does not provide a high conversion rate due to the influence of any 5 diodes. When using a high-precision key; having a control input, the disadvantage of the device is reduced reliability, since in the event of an accidental failure of one of the

20 counting triggers the normal operation of the device is disrupted.

The purpose of the invention is to increase the reliability of the converter.

The goal is achieved by

25 that, in the known converter of the period of the pulse following to voltage, containing a source of a heterogeneous field p1; th standard voltage, adder and input trigger, counting

The input of which is connected to the input bus of the converter, and the zero and single outputs are connected to the inputs of the first and second channels for the formation of a linearly varying voltage. each of which contains a counting trigger, an integrator with a DC compensator, the input of which is connected to a source of a different polarity reference voltage through a switch, the control input of which is connected to the unit output of the counting trigger, and an inverter whose input is connected to the output of the integrator the outputs of the inverter and integrator are connected via the first and second keys respectively to the input of the adder, the single output of the counting trigger of the second channel is connected to the synchronizing input of the counting trigger rapervogo- channel control input of the first switch of each channel is connected with a unit of a countable output latch opposite the channel, and each channel control key input coupled to the zero output of flip-flop counting opposite channel.

FIG. 1 shows a structural electrical converter circuit; in fig. 2 - timing diagrams of the converter.

The device contains input 1, counting triggers 2 and 3, a source of 4 different voltage, switches 5 and 6, integrators 7 and 8, inverters 9 and 10, keys 11 and 12, shapers 13 and 14 short pulses, electronic KEYS 15-18 and adder 19.

The output of the source signal is connected to the input of the trigger 1, the unit output of which is connected to the input of the counting trigger 2 of the first channel of linearly varying voltage, and the zero output is connected to the input of the linearly variable voltage of the second channel

The single output of trigger 2 is connected to the control input of switch 5, the output of which is connected to the input of integrator 7, and the single output of trigger 3 is connected to the control input of electronic key b, the output of which is connected to the input of integrator 8. The inputs of switches 5 and b are connected to source 4 of different polarity reference voltage. The output of the integrator 7 is connected to the input of the inverter 9, and the output of the integrator 8 is connected to the input of the inverter 10. In addition to

In addition, the output of the integrator 7 is connected to the input via a shunt switch 11, the control input of which through the driver 13 short pulses is connected to the single output of the counting trigger 3, and the output of the integrator 8 s

. using a shunt key 12 is connected to the input, and the control

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the shunt key input 12 through the short pulse shaper 14 is connected to a single output of the trigger 2. The key 11 and the short pulse shaper 13 form a capacitor of a constant component of the integrator of the first channel for forming a linear voltage, and the key 12 and the shaper 14 short pulses are a constant compensator component of the integrator of the second channel. The outputs of the integrator 7 and the inverter 9 are connected via switches 15 and 16 to the input of the adder 19, the control input of the switch 15 being connected to the single output of the trigger 3, and the controlling input of the switch 16 connected to the zero output of the trigger 3. Similarly, the outputs of the integrator 8 and the inverter 10 through the summing keys 17 and 18 are connected to another input of the adder 19. The control input of the key 17 is connected to the single output of trigger 2, and the control input of the key 18 is connected to zero output of the trigger 2.

(- input signal, U and U - respectively, the signals of the single and zero outputs of the trigger 1, ul and ul - the signals of the single outputs of the trigger 2 and 3, respectively, U- - U, - - the output signals of the corresponding elements of the block diagram (figure 2 )

The Converter operates as follows.

The converting signal arrives at the counting input of trigger 1, switches it, and is converted into a rectangular signal at its output. The received pulses from the single output of trigger 1 arrive at the counting input of trigger 2 and switch it, a. the pulses from the zero output of the trigger 1 arrive at the counting input of the trigger 3 and switch it. Since the unit and zero outputs of the trigger 1. the resulting rectangular pulses have a mutual phase shift of 180, then on single outputs of the flip-flops 2 and 3 the pulses will have a phase shift of 90 ° relative to each other. These pulses, which are shifted in relation to each other by 90 °, are fed to the control inputs of switches 5 and 6, which are alternately connected to the inputs of integrator 7 and 8, the input reference voltage of different polarities + UST. - UST on source 4. As a result of integrating the obtained rectangular pulses at the outputs of the integrators 7 and 8, a triangular voltage is formed with a phase shift relative to each other by 90 ° and with an amplitude proportional to the pulse period of the input pulses.

To eliminate the influence of a constant component, which can accumulate at the outputs of the integrator 7 and R from the zero drift and in transient modes 5 of the converter, at the moment the output triangular voltage passes through the zero level, the outputs of the integrators 7 and 8 are connected for a short time the input through the keys 11 and 12. These Keys are opened with a short pulse received from the formers 13 and 14 short pulses, which in turn are triggered by triggers 2 and 3.

From the output of each integrator 7 and 8, triangular voltage inputs to the inputs of inverters 9 and 10, and then from the outputs of integrators 7 and 8 and inverters 9 and 10, four signals of a triangular shape are fed to the inputs of summing keys 15-18. With the help of these keys, the negative part of the half-period of the triangular voltage is cut off and only the positive half-periods of the triangular voltage are received at the inputs of the analog adder. The summation of these signals at the output of the adder 19 produces a signal in the form of a constant voltage, the value of which is equal to the amplitude value of the triangular voltage, m, e, is proportional to the period of the input signal.

In order for the output pulses of the counting triggers 2 and 3 of the formation of a linearly varying voltage to always have a phase shift relative to each other by 90, the auxiliary input of the counting trigger 2 of the first channel from the single output of the counting trigger 3 of the second channel receives the synchronization pulses. If one of the triggers accidentally fails, the sync pulse restores the normal operation of the device.

Thus, due to the distinctive features of the invention, the reliability of the device is improved while maintaining high accuracy.

The formula of "invention

A pulse period to voltage transducer containing a source of a different polarity reference voltage, an adder and an input trigger, the counting input of which is connected to the input bus of the converter, and the zero and single outputs are connected to the inputs of the first and second linearly varying voltage inputs each of which contains a counting trigger, an integrator with a constant-level compensator, whose input is connected to a source of a different polarity of the reference voltage through a switch controlled Its input is connected to a single output of a counting trigger, and an inverter whose input is connected to an integrator's output, and the outputs of the inverter and integrator are connected via the first and second keys respectively to the input of the adder, characterized in that, in order to increase the reliability of the conversion, the single output counting

5, the trigger of the second channel is connected to the synchronizing input of the counting trigger of the first channel; the control input of the first key of each channel is connected to the single output of the counting

0 is the trigger of the opposite channel, and the control input for the second key of each channel is connected to the zero output of the counting trigger of the opposite channel.

five

Sources of information taken into account in the examination

1. USSR author's certificate

No. 382228, cl. N OZ K 13/16, 04.11.69.

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2. Authors certificate of the USSR 571897, cl. H 03 K 13/16, .7f5

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Claims (1)

Claim A converter of the pulse repetition period to a voltage containing a source of a bipolar reference voltage, an adder and an input 5 trigger, the counting input of which is connected to the input bus of the converter, and the zero and single outputs are connected to the inputs of the first and second channels of the formation of a linearly varying voltage, each of which contains a counting trigger, an integrator with a DC compensator, the input of which is connected to a source of bipolar standard voltage through a switch that controls the first input of which is connected to the single output of the counting trigger, and the inverter, the input of which is connected to the output of the integrator, and the ed outputs of the inverter and integrator are connected through the first and second keys respectively to the input of the adder, characterized in that, in order to increase the reliability of conversion, a single output counting 4 ³ triggers of the second channel are connected to the synchronizing inputs of the counting trigger of the first channel, the control input of the first key of each channel is connected to a single output of the counting, 30 triggers of the opposite channel, and the control input of the second key of each channel is connected to the zero output of the counting trigger of the opposite channel.