SU1404959A2 - Device for measuring high voltages - Google Patents

Abstract

The invention is intended to measure constant voltage, as well as amplitude values of pulsating, pulsed, and alternating voltages in high voltage electrical circuits. The device for measuring high voltages contains a rectifying diode 1, zener diodes 2, current stabilizer 4, voltage suppressor 5, measuring unit 6, input terminals 7, 8, measurement limit switches 3, made in the form of a tunnel diode and two field-effect transistors. The device has an increased measurement performance and an extended dynamic range. 2 Il. with S (L 4: CD 4: o ate 14)

Description

The invention relates to electrical measuring equipment and is intended to measure DC voltage as well as amplitude values of pulsed, pulsed and alternating voltages in high-voltage electrical circuits, and is an improvement of the known device according to author. No. 661355.

The purpose of the invention is to improve the performance of measurements. And expanding the dynamic range.

FIG. 1 shows a functional diagram of the device; in fig. 2 - type of measured voltage.

The device contains a rectifying diode 1, serially connected zener diodes 2, switches 3 measuring limits, the first output of which is connected to the cathode, and the second output to the anode of the corresponding Zener diode 2, the anode of the last Zener diode 2 is connected to the inputs of the current stabilizer 4, voltage suppressor 5 unit 6 (for example, an oscilloscope), the first input terminal 7 of the device is connected to the anode of the rectifying diode 1, the cathode of which is connected to the cathode of the first zener diode 2, the second terminals of the current stabilizer 4, granichitel

5 voltage and measuring unit

6 are connected together with the second input terminal 8.

Each measurement limit switch 3 contains two field-effect transistors 9 and 10 and a tunnel diode 11, while the drain of the field-effect transistor 10 is connected to the first output of the switch 3 of the measurement limits, the second output of which is connected to the gate of the field-effect transistor 9 and the cathode of the tunnel diode 11, the anode which is connected to the gate of the field-effect transistor 10 and the source of the field-effect transistor 9, the drain of which is connected to the source of the field-effect transistor 1

The device works as follows.

The monitored voltage is applied to terminals 7 and 8. In the initial state, the field effect transistors 9 and 10 and the tunnel diodes 11 are in the open state. The operating point of the tunnel diodes 11 is fixed by a current stabilizer 4- on the first branch of its current-voltage characteristic of the field-effect transistors

0

five

0

five

0

five

0

five

9 and 10 are also fixed and the total voltage drop across the switches 3 of the measurement limits has a certain value, for a given stabilization current. When the measured voltage exceeds the threshold of the voltage limiter 5, a stabilizer shunting occurs. current, which leads to an increase in current in the circuit above the peak switching value of one of the tunnel diodes 11 and, accordingly, an increase in the voltage drop across it, equal to the voltage of the solution of the tunnel diode 11. This leads to almost complete locking of the corresponding field-effect transistors 9 and 10 and redistributing the device stabilization current between Zener diode 2 and a circuit consisting of field-effect transistors 9 and 10 and tunnel diode 11. Thus, a zener diode is connected and a corresponding drop appears on it April voltage. When reducing the current in the circuit below the current. releasing the tunnel diode 11 circuit returns to its original state.

The magnitude of the peak current, the L-start current and the voltage of the solution depends on the type of tunnel diodes used, the peak current of the tunnel diodes 11 must be greater than the stabilization current of the Zener diodes 2, and the peak current values in each of the electronic switches must be different from each other. to exclude the simultaneous inclusion of several of them.

As a result of switching the measurement limits, the signal at the output of the device when measuring increasing voltage is in the form of a series of pulses (Fig. 2), with the amplitude of the last pulse equal to the change in voltage drop across the current stabilizer after the last switched stage. Then the measured voltage U ,, can be determined by the formula I

0

and ism Tso

N

+ Gi

Iro

+ 4U

five

where n

whether

- the number of switched device stages (the number of pulses in the output signal of the device),

-amplitude of the last (incomplete) pulse at the output of the device (FIG. 2) |

stabilization voltage of the 1st Zener diode 2; In addition, the voltage drop across the on switches of the 3 measurement limits.

Claims (1)

Invention Formula Device for measuring high voltages according to avt.St. No. 661355, which is related to the fact that, in order to increase the measurement performance and increase the dynamic range, the limit switches The measurements are made in the form of a tunnel diode and two field-effect transistors, the source of the first field-effect transistor is connected to the drain of the second on-left transistor; is the second output of the corresponding measurement limit switch, the first output of which is the drain of the first field-effect transistor. .2