SU705673A1 - Voltage to frequency converter - Google Patents

Description

(54) VOLTAGE CONVERTER IN FREQUENCY

-one. -: /

The invention relates to measurement technology and can be used in the statistical and dynamic measurement of the C bridge by sensors.

A voltage-to-frequency converter is known, which contains an integrated amplifier, KOMnapaix) p, keys, And elements, triggers, a frequency generator, in which the output frequency signal is formed as a result of accumulation of the measured voltage on the HHtei amplifier and resetting this pattern using a reference voltage for a stable time interval {1.,

However, the device has low conversion accuracy.

A known voltage-to-frequency converter contains an integrating amplifier whose input is through the first resistor with the output of the measured voltage source and the output of the reference voltage source through two series-connected resistors, the common point of which is connected to the output of the key, the trigger, the first input of which connected to the output of the comparator, connected to the INPUT with the output of the integrating amplifier, and the second input - with the output of the frequency generator and with the nepBbiM Input element And, the second input of which is connected to the first exit

trigger I 2 .:

However, the device has low conversion accuracy.

; The purpose of the invention is to improve the accuracy of conversion.

To do this, a voltage to frequency converter containing a power supply, a bridge sensor, a scale amplifier, a voltage source, a frequency generator, an AND element, a TfMirrep, a comparator, an integrating amplifier, and three resistors are inserted into an inverter, an additional switch, and two additional a resistor, and the input of the inverting amplifier is connected

Claims (2)

with the second; the output of the voltage source, and the output through serially connected additional resistors connected by a common point to the output of the additional switch, whose input is connected to the second output of the figger, is connected to the input of the integrating amplifier. FIG. Figure 1 shows the structural electrical circuit of the device; in fig. 2 - timing charts of the device. The voltage to frequency converter contains a power supply unit, a bridge sensor 2, a large-scale amplifier 3, a resistor 4, an integrating amplifier 5, a reference voltage source 6, resistors 7, 8, a switch 9, a comparator 10, a trigger 11, a frequency generator 12, and element 13, inverting amplifier 14, resistors 15, 16, switch 17. The device operates as follows. The voltage from unit 1 enters the power supply diagonal of bridge sensor 2 and to the input of source 6. As a result, a signal appears at the output of bridge sensor 2, which is amplified by a large-scale amplifier 3 and through a resistor 4 is fed to the input of an integrating amplifier 5. As a result, the voltage at the output of the integrating amplifier 5 accumulates and at a certain moment goes to zero, then (Fig. 2) the comparator 10 will change its state to the opposite and give permission to one of the trigger inputs that will work from the first, then ; a pulse that has passed after this, which has been sent to the second input of the trigger 11c of the generator 12. From the output of the trigger 11, the time is controlled, during which the reference voltage is applied to the integrating amplifier 5. This control is performed by iodizing the control voltage from trigger 11 to key 9. The reference voltage is fed to the input of the integrating amplifier 5 through the series-connected resistors 7 and 8. Thus, the integrating amplifier 5 pbIt accumulates the voltage from the scale amplifier 3, but when this voltage passes through the bullet point, it is reset by the reference voltage generated by SOURCE 6 in the time between two pulses from the generator 12. If the output signal of the bridge sensor is 2 SW lichivaets then increases and sh5rZh1ShShgshoM ShzfShSh conductive Hilti amplifier 5) and hence the frequency of this reset voltage reference voltage. The control from trigger 11 simultaneously feeds one of the element 13 inputs, and the other ii coffkotopiW cTynaeT signal from generator 12. Thus, a b1 frequency will be part of the frequency of generator 12, and its frequency is the maximum frequency of the device. the switching frequencies of the trigger 11 and the output frequency will be accurately synchronized. The key 17 is the HN1 e1 cor1) of the operation of the integrating amplifier 5 at the time of the operation of the key 9 of the reference voltage. The purpose of this correctional is as follows. If the bridge sensor 2 has become unbalanced during operation, the voltage at the outputs of source 6 will also be asymmetrical. The inverting amplifier 14 inverts at one of the outputs of source 6, the voltage that flows through resistors 15 and 16 to the input of the hot wire amplifier 5. At the same time, two reference voltages of the same polarity and asymmetry signals that are in phase opposite will appear at its input and compensating each other. Thus, the synchronous operation of the keys 9 and 17 allows for the correction of the asymmetry of the bridge sensor 2 and the resulting asymmetry of the reference voltage. The introduction of an inverting amplifier, additional resistors and an additional switch increases the accuracy of voltage conversion of the bridge sensor by compensating for the unbalance of the reference voltage, and the error of the conversion, due to a change in the input resistance of the inverting amplifier, will reach the maximum value of 6, where in RMS some change in impedance at the input of the amplifier, while at the summing amplifier with inverting and non-inverting inputs it is equal to 2 0. Thus, the proposed converter gives an increase in the cbness of at least 2 times. Claims of the Inverter Voltage-to-frequency converter containing a power supply unit whose outputs are connected to the inputs of the bridge gate and source (reference scale, the output of the bridge sensor is connected to the input of the mashig amplifier, integrating amplifier whose input is connected to the output of the scale amplifier through the first resistor and with the first output of the source of the reference voltage through two series-connected resistors, a common point of which is connected to the output of the key, a trigger, the first input of which is connected to the output of an imparator connected to the input of an integrating amplifier, and the second to the output of a frequency generator and the first input of an element I, the second input of which is connected to the first output of a trigger, the second output of which is connected to the input of a switch, characterized in that , 5–70567 entered a switching-off amp, an additional switch and two additional resistors, the input {of the power inverter connected to the second output of the reference voltage source, and its output to the input of the integrating amplifier Itel through additional connected resistors in series, connected by a common point to the output of an additional key, the input of which is connected to the second output of the trigger. 10 g. r + Sources of information taken into account during the expert review .I. Copyright certificate of the USSR. №544127, cl. H 03 K 13/20, 1976. 2. Express information1 Devices and elements of automation and computing. A new method of converting analog signals to numerical form, 1974, N 47, p. 5-9, (prototype) F1P.1