RU1800407C - Device for testing electric circuits - Google Patents

Abstract

The invention relates to electrical measurements and is intended to control the presence of voltage in alternating and direct current circuits, determining the range of the controlled voltage, determining the polarity, and continuity of the circuits. SUMMARY OF THE INVENTION: the device contains five light emitting diodes, five zener diodes, four diodes, six resistors, two miniature sealed relays; a capacitor charged during voltage monitoring is used as an internal power source in the device. When monitoring electrical circuits, a particular LED or a specific combination of them lights up, and an audible signal is emitted by vibrating relays. The operating voltage range of the device is 24-380 V. 1 il.

Description

The invention relates to measuring equipment and is intended to control the presence of voltage and the integrity of electrical circuits in electrical installations.

The aim of the invention is to expand the functionality and scope of the device by allowing the approximate determination of the level of the monitored voltage and providing sound accompaniment when monitoring the presence of voltage.

The drawing shows a circuit diagram of the device.

The device for monitoring electrical circuits contains two probes 1 and 2, a capacitor 3, a four-arm bridge formed by diodes 4, 5, 6, 7, zener diodes 8 and 9, LEDs 10 and 11, as well as resistors 12-15, zener diode 16 and LED 17, miniature sealed electromagnetic relays 18 and 19, for example, type RES-49, resistors 20 and 21, zener diodes 22, 23 and LEDs 24,

25, connected in series with contacts 18/1 and 19/1 of the relay. The LEDs are located next to the corresponding inscriptions on the device case: 10 - Pr (circuit continuity); (polarity on the main probe 1), 17 - 24-200 V (range of controlled voltages), 24 - 127-220 V (range of controlled voltages). 25 - 380 V (controlled voltage level).

The device operates as follows.

When connecting probes 1 and 2 to a controlled constant current source and positive potential on probe 1, the current flows through the circuit: diode 4 - LED 11 with a zener diode 9 - resistors 13 and 12 - windings of relays 19 and 18 with zener diodes 20 and 23 - resistor 20 - probe 2. The capacitor 3 is not charged due to the shunt action of the diode 4 and LED 11. The voltage on the lit LED 11, in

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The oscillating - is maintained unchanged thanks to the Zener diode 9 over a wide range of controlled voltages. With the help of resistors 20, 21 and zener diodes 22, 23, the relay threshold is set: about 127 V of relay 18 and about 350 V of relay 19. When monitoring the presence of voltage, either voltage 18, or relay 19, or neither one relay. In any case, the LEDs 17, 24, 25 will not turn on due to the blocking action of the diodes 5 and 7. In this mode, the inscription is indicated by the LED 11. To determine the voltage in the monitored circuit, swap the probes 1 and 2. In this case, positive potential on probe 2, the current flows through the circuit: resistor 20 - relay 18.19 with zener diodes 22, 23-zener diode 16 and LEDs 17, 24, 25 - resistor 14 - resistor 15 - diode 6 - and a parallel branch: zener diode 8 - diode 7 - capacitor 3 - probe 1. LEDs 10 and 11 do not light up due to blocking action twi diode 4. Zener diode 16 maintains constant voltage on the LEDs 17, 24, 25, and zener diode 8 - on the capacitor 3. The process of charging the capacitor 3. The light is on either LED 17 (relays 18 and 19 are off), or LEDs 17 and 24 (relay 18 is on), or LEDs 17, 24, and 25 (relay 18 and 19 are on).

The LED 11 also lights up on alternating current (with alternating voltage polarity on the probes). In addition, the alternating current causes vibration of relays 18 and 19 (which does not cause the LEDs to notice the eye) with a frequency of 100 Hz, which is clearly audible to the operator (when voltage up to 220 V of one relay 18, and with a voltage of 380 V, respectively, both relays 18 and 19). Zener diodes 22 and 23 protect the relay windings from overload, and the resistor 21 provides the simultaneous operation of relays 18 and 19.

In the continuity mode, the capacitors 3 must be pre-charged either specially by briefly touching the probes 1 and 2 to the AC or DC source, or automatically during the previous voltage control operations. In this case, the current flows through the circuit: from + capacitor 3 through LED 10 and diode 5-resistors 13,12 - relay windings 18, 19 - resistor 20 - probe 2 - controllable circuit - probe 1 - minus capacitor 3. At the same time, LED 10 lights up.

The device operates in the voltage range of 24-380 V. The resistance of the controlled circuit is up to 15 kOhm.

Claims (1)

The claims Device for monitoring electrical circuits, comprising two test probes, an internal power supply, three LEDs and two resistors, characterized in that, in order to expand the functionality and scope of application, four resistors, four diodes, five zener diodes are additionally introduced into the device and second miniature sealed electromagnetic relays with a closing contact each, fourth and fifth LEDs, and used as an internal power source a capacitor with a low leakage current, connected by a minus to the first probe, and four diodes, two zener diodes, two LEDs form a four-arm bridge, in the first arm of which sequentially and according to the first LED and the first diode, in the second, opposite shoulder - the second diode and the first zener diode connected in series counterclockwise, in the third shoulder - the third diode and the second LED connected by the second zener diode, shunted by the second zener diode, sequentially in the fourth, opposite the third shoulder, - the fourth diode, and the common point of connection of the cathodes of the first and third diodes of the bridge is connected to the second probe through a chain of series-connected first and second resistors, and the common point is connected the inode of the anode of the fourth diode and the cathode of the first zener diode of the bridge is also connected to the second probe through a chain of series-connected third and fourth resistors and a third LED, the fourth resistor with a third LED shunted by the third zener diode, the positive terminal of the capacitor is connected to a common point of connection of the anode of the first LED and the cathode of the fourth diode, the fourth and fifth zener diodes are connected between each other in series and together with a series-connected third resistor are included in the open circuit of one of the probes of the device, and parallel to the chain of these zener diodes the windings of the first and second relays are connected in series, the latter is shunted by the fourth resistor, the fourth LED forms a series circuit with the closing contact of the first relay, and the fifth LED forms a series circuit with the closing contacts of the second relay, both of which are connected in parallel with the LED. indicating plus in the device. fifteen 14