SU961136A1 - Integrating voltage to time interval converter - Google Patents

Description

This invention relates to electrical measuring technology. Integrating voltage converters in the time interval are known, in which the subsequent summation of the conversion results 1 is necessary. However, the task is reduced to a digital measurement of the sum of non-adjacent time intervals, which leads to an error due to the discreteness of the number of pulses. reference frequency, filling each of the output intervals. The maximum value of the absolute error can reach the number of packs of summing pulses. There are statistical methods for reducing this error, which only reduce the probability of this error. The closest in technical essence to the proposed is the converter containing the first tegrator, the OUTPUT of which is connected to the input of a noninverting amplifier,. the output of the latter is connected via the first key with the first input of the first integrator, the second input of which is connected to the source of the converted quantity, the third input is connected to the source of the reference voltage, the output of the first switch is connected to the first input of the second integrator whose output is connected to the input of the non-inverting amplifier - zero -organ, whose output via the second key is with the second input of the second integrator, the third input of the latter is connected to the source of the reference voltage, the output of the non-inverting amplifier is zero-body and control ode keys are connected to outputs of the control device, whose input is connected to the output of clock pulse generator 2. The disadvantage of this conversion is the presence of the error

when summing a number of non-contiguous time intervals.

The aim of the invention is to improve the accuracy of the conversion.

The goal is achieved by integrating a voltage converter into a time interval containing the first integrator, the output of which is connected to the input of a non-inverting amplifier, the output of the latter connected via the first key to the first input of the first integrator, the second input of which is connected. with the source of the converted value, the third input is with the source of the reference voltage, the output of the first key is connected to the first input of the second integrator, the output of which is connected to the input of the non-inverting zero-organ amplifier, the output of which is connected via the second key to the second input of the second integrator, the third input of the last connected to a source of reference voltage, the output of a non-inverting amplifier-zero organ, and the control inputs are connected to the outputs of a control device whose input is connected to the output of the clock generator s pulses entered the third switch, through which the amplifier vyhod.neinvertiruyuschego - zero-body is connected with additional input of the integrator, the third switch control input connected to an additional output of the control device.

FIG. 1 is a functional diagram of an integrating voltage converter over a time interval.

The integrating voltage / time converter comprises integrators 1 and 2, a non-inverting amplifier 3. A non-inverting amplifier — null organ, keys, control device 8, a clock pulse generator 9, the converter input being the input of the integrator 1, whose output is connected to the non-inverting input amplifier 3, the output of the latter through the switch 5 is connected to the inputs of the integrators 1 and 2, the source of the reference voltage is connected to the inputs of the integrators 1 and 2, the output of the integrator 2 is connected to the input of a non-inverting amplifier “A null organ, the output of which through keys 6 and 7 is connected to the inputs of integrator 1 and 2, the control inputs of the keys and the output of a non-inverting amplifier — the zero-organ f are connected to

The control device 8, the output of the clock generator 9 is connected to the input of the control device 8. FIG. 2 shows a temporary

diagram illustrating the operation of the converter, where: 10 is the output voltage of the integrator 1; 11 is the output voltage of the key 5 12 are the pulses of the reference frequency; 13 is the output voltage of the integrator 2} 14 is the output voltage of the non-inverting amplifier — null organ; 15 - output voltage of key 6.

Consider the work of the converter,

Beginning at time t ,, when key 5 is opened by a command from control device 8. Voltage

integrator-1 output at time t / j reaches

X 0

H S) R: -1)

The voltage at the output of the INTERRATOR 2 at the moment reaches the value

) - (v) As can be seen from the time diagrams, the moment t corresponds to the equality, zero of the output voltage of the integrator 2. At this moment, yupyu 6 is closed. Under the action of negative feedback, the output of the switch 6 will set a voltage equal to

R.

35 u- (j

which goes to the input

About R:

integrator 1 over time (.). At time I, corresponding to the arrival of the next reference frequency pulse, key 6 is closed.

The key 7 at time 13 is opened and intended to maintain the integrator 2 in the zero state until time point t ,. The expression for the output voltage of the integrator 1 at time t is the following

W (tj) -e; (VS) -4

and

; (S-H)

(,

Considering that /

and. and

 () R

m

"S

"Ni

uh |

Claims (1)

5 claims An integrating voltage converter in the time interval containing the first integrator, the output of which is connected to the input of a non-inverting amplifier, the output of the latter is connected via the first key to the first input of the first integrator, the second input of which is connected to the pre-? ^{15 of the} generated value, the third input with a voltage source, the output of the first key is connected to the first input of the second integrator, the output of which is connected to the input of a non-inverting amplifier - a zero-organ, the output of which is connected through the second key to the second input of the second integrator, the third the input of the latter is connected to the source of the reference voltage, the output of the non-inverting amplifier 39 output pulses, characterized in that, in order to increase accuracy, a third key is introduced into it, through which the output of a non-inverting amplifier, a zero-organ connected to 35, is connected to additional inputs of integrators, the control input of the third key is connected to the additional output of the control device .