SU1001462A1 - Voltage-to-time internal converter - Google Patents

Description

The invention relates to electrical measuring equipment and can be used in digital devices for special and universal purposes.

A voltage to time converter is known, containing a first switch, the output of which through the first resistor is connected to the first input of an integrator, the second input of which through the second resistor is connected to the output of the second switch, and the output through the comparison unit is connected to the first input of the third switch and the first the input of the second key, the second input of which is connected to the second input of the third key and the input of the control unit, the output of which is connected to the input of the first key. The disadvantage of this device is low sensitivity.

A known voltage converter in the time interval, contents. The first integrator, the output of which is connected to the first input of the comparator, the second input of which through the swarm integrator is connected respectively to the first input of the first integrator, to the first output of the reference voltage source and first

the input of the switch, the output of which is connected to the second input of the first integrator, the second input is connected to the second output of the reference voltage source, and the third input is connected to the input of the reset unit and the trigger output, the first input of which is connected to the comparator output, the second input is connected to the generator output

10 pulses, and the output of the reset unit is connected to the reset input of the second integrator 2.

A disadvantage of the known device is low sensitivity.

15

The purpose of the invention is to increase the sensitivity.

This goal is achieved by the fact that the voltage converter has an initial integrator, the first input of which through the second integrator is connected to the first input of the comparator, the second input to the output of the switch, and the output to the second input cm of the comparator, the output of which is connected to the first input of the trigger, the second input of which. connected to the output of the pulse generator, and the output to the first input

30 switch with the input of the reset unit, the output of which is connected to. the control input of the second integrator is entered by a sign analyzer and the switch of the first and second inputs of which are connected to the output source of the reference voltage, the third and fourth inputs respectively to the output of the pulse generator and to the output of the sign analyzer, the first input of which is connected to the output of the first integrator, and the second The entrance is with a shared bus.

FIG. 1 is an electrical diagram of the device according to the invention; FIG. 2 - timing charts of the proposed device.

The device contains an integrator 1, a comparator 2, a source of reference voltage 3, a switch 4, an integrator 5, a character analyzer b, a switch 7, a reset unit 8, a trigger 9, a pulse generator 10.

The timing diagram shows the measured voltage, clock pulses, the voltage at the inputs of comparator 2, the voltage at the output of trigger 9, the voltage at the output of analyzer 6, the voltage at the output of switch 4, the sample voltage at the input of the integrator 1 .

The device works as follows.

At time t, a pulse arrives from the generator 10 and sets the trigger 9 to the position where the switch 7 connects to the first input of the integrator 1 a negative reference voltage (jg, and block 8 turns off.)

After that, the voltage at the output of the integrator 1 begins to linearly return, and the voltage at the output of the integrator 5 decreases linearly. At time t, they become equal, and comparator 2 is triggered. This triggers the trigger 9, which by means of the switch 7 cuts the exemplary voltage UQ from the input of the integrator 1 and turns on the block 8, as a result of which the output of the integrator 5 sets a voltage equal to zero. At time tj, the pulse flips trigger 9, then the work cycle repeats when changing the sign of the input voltage occurring at time t, the output signal of integrator 1 at time t becomes paBHbiM zero and then increases linearly. At the same time, at the moment of time t, an output appears at the output of the analyzer b, which prepares the operation of switch 4. As soon as a clock frequency pulse arrives at time t5, it triggers and connects to the input of switch 7

exemplary -hUp voltage. If at time t the input voltage (Jy becomes positive again, at time t the output of analyzer b appears pulse, but of a different polarity compared to time tg-. This pulse prepares the connection to the input of switch 7 of the reference voltage UQ The conversion process is described by a system of equations.

(CO-CU

1st i g h

Ui Ti-T consb,

where 1G is the time constant of integratra;

T is the conversion time. The joint solution of two equations gives a function of the form

From this expression it can be seen that the range of variation of the parameter T is twice as large as in the known device. Therefore, the sensitivity of the proposed device increases.

Claims (2)

1. Shl ndin V.M. Digital electrical measuring instruments. M., Energie, 1972, p. 147, fig. 3-43 a. 2. USSR author's certificate on application 2037545, cl. H 03 K 13/20, 1974 (prototype).