JP2598921Y2 - Voltage check circuit - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage checking circuit provided in a protection device for protecting a power system and for checking whether or not a voltage is applied to a test terminal of the protection device.

[0002]

2. Description of the Related Art In a protection device for protecting a power system, a voltmeter or a tester is connected to a test terminal to check the presence or absence of a voltage, and the operation of the protection device is confirmed based on the check result. Like that.

[0003]

However, in such a protection device, since the test terminal and the circuit breaker in the protection device are internally connected, a tester is connected to the test terminal to check for the presence or absence of a voltage. When checking,
The measurement mode of the tester is set to the voltage measurement mode to check the voltage of the test terminal. At this time, for example, if the measurement mode is switched to the resistance measurement mode, the voltage is supplied from the tester to the test terminal, and a cutoff command or a closing command is erroneously output to the circuit breaker on the protection device side, which hinders power supply. There was a problem that would cause.

In view of the above circumstances, the present invention can check whether a voltage is applied to a test terminal without using a tester or the like, thereby preventing a malfunction of a circuit breaker of a protection device. It is intended to provide a voltage check circuit.

[0005]

In order to achieve the above object, a voltage check circuit according to the present invention comprises a display provided in a protection device and a voltage applied to an upper terminal of a test terminal provided in the protection device. Operated when checking whether or not voltage is applied, an upper switch for inserting each terminal of the indicator between the upper terminal of the test terminal and one power supply line, and provided in the protection device. It is operated when checking whether or not a voltage is applied to the lower terminal of the test terminal. The terminal of the indicator is inserted between the lower terminal of the test terminal and the other power supply line. And a side switch.

[0006]

In the above arrangement, when checking whether a voltage is applied to the upper terminal of the test terminal provided in the protection device, the upper switch is operated to operate the upper terminal of the test terminal and one of the power supply lines. When it is checked whether or not each terminal of the display is interposed and a voltage is applied to the lower terminal of the test terminal provided in the protection device, the lower switch is operated to operate the test terminal. Each terminal of the display is inserted between the lower terminal of the display and the other power supply line.

[0007]

1 is a circuit diagram showing one embodiment of a voltage check circuit according to the present invention.

The voltage check circuit 1 shown in FIG. 1 includes two test switches 2, 3 and two lower switches 4, 5, 1,
As shown in FIG. 2, the upper switch 6 is provided with a changeover switch 9 attached to a housing 8 constituting a protection device 7, a resistor 10 disposed in the housing 8, and a switch 10 disposed in the housing 8. And a neon lamp 12 attached to the housing 8. The presence or absence of a DC voltage applied to a test terminal (see FIG. 2) 14 of a protection device body 13 provided in the protection device 7. Is displayed by turning on / off the neon lamp 12.

One of the test switches 2 constituting the changeover switch 9 has one end connected to the P power supply line 15 and the other end connected to one end of the resistor 10 and the other end of the one lower switch 4. When the lighting check of the neon lamp 12 is performed, the lamp is closed and the voltage of the P power supply line 15 is transmitted to the resistor 10.

The lower switch 4 of the changeover switch 9 has one end connected to a P power supply line 15 and the other end connected to one end of the resistor 10 and the other end of one test switch 2. The lower terminal 14b of the test terminal 14 provided on the protection device body 13
When checking whether or not a voltage is applied between the power supply line 15 and the power supply line 15, the power supply line 15 is closed and the voltage of the P power supply line 15 is transmitted to the resistor 10.

The resistor 10 has one end connected to the other end of the one test switch 2 and the other end of the one lower switch 4, and the other end connected to the cathode of the diode 11 and one end of the neon lamp 12. Even if the neon lamp 12 is short-circuited, it prevents the DC current of a preset value or more from flowing through a circuit breaker (not shown) provided in the protection device body 13 while preventing the neon lamp 12 from short-circuiting. The voltage from the other end of one test switch 2 and the other end of the one lower switch 4 is transmitted to the cathode of the diode 11 and one end of the neon lamp 12.

The diode 11 has a cathode connected to the resistor 1.
0, and one end of the neon lamp 12, and the anode is connected to a cut-off relay contact 16 provided on the protection device body 13 and an upper terminal 14 a of the test terminal 14.
When one of the test switches 2 and one of the lower switches 4 are closed in a state in which the circuit breaker is short-circuited, the voltage is applied to the circuit breaker via the one of the test switches 2 and one of the lower switches 4. Is prevented from being supplied.

The neon lamp 12 has one end connected to the other end of the resistor 10 and the cathode of the diode 11, and the other end connected to one end of the upper switch 6, one end of the other test switch 3, and the other lower end. The switch 5 is connected to one end, and lights when a voltage is applied to both ends.

The upper switch 6 constituting the changeover switch 9 has one end connected to the other end of the neon lamp 12, one end of the other test switch 3, and one end of the other lower switch 5, and the other end connected to the N switch. When it is checked whether or not a voltage is applied between the upper terminal 14a of the test terminal 14 provided on the protection device main body 13 and the N power supply line 17, the closing operation is performed. The voltage of the N power line 17 to the neon lamp 12
To communicate.

The other test switch 3 constituting the changeover switch 9 has one end connected to the other end of the neon lamp 12, one end of the upper switch 6, and one end of the other lower switch 5, and the other end. Are connected to the N power supply line 17, when the lighting of the neon lamp 12 is checked, the operation is closed to transmit the voltage of the N power supply line 17 to the neon lamp 12.

The other lower switch 5 constituting the changeover switch 9 has one end connected to the other end of the neon lamp 12, one end of the upper switch 6, and one end of the other test switch 3. Is the test terminal 1
4 to check whether a voltage is applied between the lower terminal 14b of the test terminal 14 and the P power supply line 15 when the test terminal 14 is closed. 14 lower terminal 14b
Is transmitted to the neon lamp 12.

Next, the lighting check operation of the neon lamp 12 and the voltage application presence / absence test operation of the test terminal 14 of this embodiment will be sequentially described with reference to the circuit shown in FIG. 1 and the external view shown in FIG.

First, when the changeover switch 9 attached to the housing 8 is operated and turned off, each test switch 2, 3 and each lower switch 4,
5. Each of the upper switches 6 is opened.

Accordingly, the neon lamp 12 is turned off regardless of whether a voltage is applied to the upper terminal 14a and the lower terminal 14b of the test terminal 14.

In this state, when the changeover switch 9 is operated to switch from the "off" state to the "test" state, the test switches 2 and 3 constituting the changeover switch 9 are closed.

As a result, a voltage is applied to the neon lamp 12 through the path of the P power supply line 15 → one test switch 2 → resistor 10 → neon lamp 12 → the other test switch 3 → N power supply line 17. Is checked for success.

If the neon lamp 12 is lit in this state, it is recognized that the neon lamp 12 is normal.

Thereafter, when the changeover switch 9 is operated to change the "test" state to the "upper" state, the test switches 2 and 3 constituting the changeover switch 9 return to the open state, and the upper switch 6 is closed.

Thus, a path of the upper terminal 14a of the test terminal 14, the diode 11, the neon lamp 12, the upper switch 6, and the N power supply line 17 is formed.
When there is a potential difference between the upper terminal 14a of the test terminal 14 and the N power supply line 17, that is, when a voltage is applied to the upper terminal 14a of the test terminal 14, the neon lamp 12 is turned on.

Next, when the changeover switch 9 is operated to change from the "upper" state to the "lower" state, the upper switch 6 constituting the changeover switch 9 returns to the open state and the lower switches 4 , 5 are closed.

Thus, the P power supply line 15 → the one lower switch 4 → the resistor 10 → the neon lamp 12 → the other lower switch 5 → the lower terminal 14 of the test terminal 14
b is formed, and when there is a potential difference between the lower terminal 14b of the test terminal 14 and the P power supply line 15, that is, when no voltage is applied to the lower terminal 14b of the test terminal 14, Neon lamp 1
2 lights up.

As described above, in this embodiment, only the operation of the changeover switch 9 to select “upper side” or “lower side” and check whether the neon lamp 12 is turned on or off can be performed. Since it is possible to check whether a voltage is applied to the lower terminal 14a and the lower terminal 14b, it is possible to check whether a voltage is applied to the test terminal 14 without using a tester or the like. Thus, the circuit breaker of the protection device 7 can be prevented from malfunctioning.

[0028]

As described above, according to the present invention, it is possible to check whether or not a voltage is applied to the test terminal without using a tester or the like. Malfunction can be prevented.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of a voltage check circuit according to the present invention.

FIG. 2 is an external view showing an example of the external appearance of the voltage check circuit shown in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Voltage check circuit 2, 3 Test switch 4, 5 Lower switch 6 Upper switch 7 Protector 8 Housing 9 Changeover switch 10 Resistance 11 Diode 12 Neon lamp (indicator) 13 Protector main body 14 Test terminal 14a Above test terminal Terminal 14b Lower terminal of test terminal 15 P power line 17 N power line

Claims (1)

(57) [Scope of request for utility model registration] An operation is performed to check whether a voltage is applied to an indicator provided on a protection device and an upper terminal of a test terminal provided on the protection device, and an upper terminal of the test terminal is operated. An upper switch for interposing each terminal of the display between the power supply line and one of the power supply lines; and checking whether a voltage is applied to a lower terminal of a test terminal provided in the protection device. A lower switch that is operated and allows each terminal of the display to be inserted between the lower terminal of the test terminal and the other power supply line.