JPH08205376A - High voltage generating device and high voltage test device - Google Patents

Abstract

PURPOSE: To provide a high voltage generating device which is operable only in the state of being completely grounded and a high voltage test device using it. CONSTITUTION: A high voltage generating circuit 11 is contained in the inner part of a housing 10 having electric conductivity and boosts an input voltage Vi to generate a high output voltage Vo. Output terminals 12. 13 supply the output voltage Vo to a device under test 3. Housing terminals 14, 15 are mechanically and electrically connected to the housing 10 in each different position. A grounding wire disconnection detecting circuit 2 is completed by constituting a closed loop CL including the housing terminal 14, the housing 10, the housing terminal 15 and two different grounding points E1, E2, and it is detected whether the closed loop CL is closed or not and when the closed loop CL is not closed, the input voltage Vi supplied from a power supply 16 to the high voltage generating circuit 11 or the output voltage Vo supplied to the device under test 3 is cut off.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high voltage generator used for insulation resistance measurement, withstand voltage test and the like, and a high voltage tester using the same.

[0002]

2. Description of the Related Art High voltage generators such as insulation resistance testers and withstand voltage testers should be grounded because there is a risk of serious electric shock to the operator if leakage occurs due to insulation deterioration. Must be used. In order to warn the operator of such danger and grounding obligation, a warning label indicating that the voltage is high has been attached and written in an instruction manual.

[0003]

However, the conventional high voltage generator has the following problems. (A) As described above, safety measures are affixing of warning labels, description in instruction manuals, etc., and it depends only on the attention of the operator, and thus cannot be a complete electric shock accident prevention means. (B) Even if a break occurs in the ground wire, the break in the ground wire cannot be detected. For this reason, even if the user intends to ground the ground, the ground wire may be broken, which may lead to a situation in which the terminal is not actually grounded, and an electric shock accident may occur due to an electric leakage.

Therefore, an object of the present invention is to provide a high voltage generator which can operate only in a completely grounded state and a high voltage tester using the same.

Another object of the present invention is to provide a high voltage generator capable of automatically detecting disconnection of a ground wire and a high voltage tester using the same.

[0006]

In order to solve the above problems, a high voltage generator according to the present invention includes a high voltage generator circuit, a pair of output terminals, two housing terminals, and a ground wire disconnection detection circuit. Including and The high voltage generation circuit is housed inside a case having electrical conductivity, boosts an input voltage supplied from a power source, and generates a high voltage output voltage. The output terminal is connected to the output side of the high voltage generation circuit and supplies the output voltage to the device under test. The housing terminals are
Mechanically and electrically connected to the housing at different positions. The ground wire disconnection detection circuit includes one of the housing terminals, the housing, the other of the housing terminals, and 2
It is completed by constructing a closed loop containing two different ground points in series. Then, it detects whether the closed loop is closed or not closed, and when the closed loop is not closed, cuts off the supply of the input voltage from the power supply to the high voltage generation circuit or the output voltage to the device under test. To do.

[0007] Preferably, the ground wire disconnection detection circuit is
A verification signal generation circuit is included, and the verification signal generation circuit supplies a verification signal to the closed loop, and detects whether the closed loop is closed or not based on the verification signal.

Preferably, the verification signal generating circuit supplies an AC verification signal to a loop including at least the two ground points in the closed loop. In one embodiment, the verification signal generating circuit includes a transformer, the primary winding of the transformer is supplied with power, and the secondary winding is inserted and connected in the closed loop. In such a case, preferably, the ground wire disconnection detection circuit includes a relay, a winding of the relay is inserted and connected in the closed loop, and a contact of the relay is an input voltage or an output voltage of the high voltage generation circuit. Inserted and connected to the supply line.

The high voltage test apparatus according to the present invention includes a device under test and a high voltage generator. The high voltage generator according to the present invention described above is used as the high voltage generator.

The device under test preferably has a pair of input terminals and at least one ground terminal, the input terminal is connected to the output terminal of the high voltage generator, and the ground terminal is The input terminal is provided at a position different from the input terminal connected to one of the output terminals of the high voltage generator, and is electrically connected. The high voltage generator and the device under test are connected so that the ground wire disconnection detection circuit is formed. The ground wire disconnection detection circuit includes one of the housing terminal, the housing, the output terminal, the ground terminal of the device under test, and 2
It consists of a closed loop containing two different grounds in series.

[0011]

The high voltage generating circuit boosts the input voltage supplied from the power source and generates a high voltage output voltage. The output terminal is connected to the high voltage generating circuit and supplies the output voltage to the device under test. As a result, a high voltage generator that supplies a high voltage to the device under test and performs insulation resistance measurement, withstand voltage test, and the like can be obtained.

The ground wire disconnection detection circuit is provided on one of the housing terminals,
Detects whether a closed loop including the housing, the other of the housing terminals and two different ground points in series is closed or not closed, and when the closed loop is not closed, the input voltage from the power supply to the high voltage generating circuit or Since the supply of the output voltage to the device under test is cut off, the disconnection of the ground wire can be automatically detected.

The closed loop constituting the ground wire disconnection detection circuit includes one of the housing terminals, the housing, and the other of the housing terminals in series. Therefore, if any one of the housing terminals is disconnected from the housing, The closed loop does not close. Therefore, the supply of the input voltage from the power supply to the high voltage generating circuit or the output voltage to the device under test is cut off. Therefore, the input voltage is not supplied from the power supply to the high voltage generation circuit or the output voltage is not supplied to the device under test when the housing is floating from the ground. It is possible to prevent an electric shock accident due to the disconnection of the ground.

Since the closed loop which constitutes the ground wire disconnection detection circuit further includes two different ground points in series, the closed loop does not close when any one of the ground points goes out of ground. Therefore, the supply of the input voltage from the power supply to the high voltage generating circuit or the output voltage to the device under test is cut off.
Therefore, in the state where the ground point floats from the ground, the power supply does not supply the input voltage to the high-voltage generation circuit or the output voltage to the device under test. , It is possible to prevent an electric shock accident.

Therefore, according to the present invention, it is possible to provide a high voltage generator which can operate only in a completely grounded state.

Further specific features and advantages of the present invention include:
A more detailed description will be given with reference to the drawings.

[0017]

1 is a block diagram showing the configuration of a high voltage generator according to the present invention and a high voltage tester using the same. The high voltage generator A according to the present invention includes a high voltage generator 11, a pair of output terminals 12 and 13, two housing terminals 14 and 15, and a ground wire disconnection detection circuit 2. The high voltage generator A of the embodiment is shown as a withstand voltage tester for evaluating the withstand voltage of the device under test 3. The device under test 3 is a choke coil. In the choke coil 3, the coil 31 is wound around the iron core 32, and the iron core 32 constitutes a housing.

The high voltage generation circuit 11 is housed inside an electrically conductive casing 10 and boosts an input voltage Vi supplied from a power supply 16 to generate a high voltage output voltage Vo. Reference numerals 17 and 18 are input terminals.

The output terminals 12 and 13 are connected to the high voltage generating circuit 1.
The output voltage Vo is supplied to the device under test 3 by being connected to the output side of the device 1. The output voltage Vo is applied between the one end 311 of the coil 31 and the housing 32.

The housing terminals 14 and 15 are mechanically and electrically connected to the housing 10 at different positions.

The ground wire disconnection detection circuit 2 includes a housing terminal 14,
Housing 10, housing terminal 15 and two different ground points E1,
It is completed by constructing a closed loop CL including E2 in series. In the embodiment, the ground terminal 21 for connecting the ground wire disconnection detection circuit 2 to the ground point E2 and the housing terminal 15 are provided.
And a connection terminal 22 for connecting to. The housing terminal 14 is connected to the ground point E1 by the ground wire 23.
The ground terminal 21 is connected to the ground point E2 by a ground wire 24. Grounding rods are provided at the grounding points E1 and E2, and the grounding rods are buried in the ground. The ground points E1 and E2 are provided close to each other in order to reduce the voltage fluctuation of the ground portion.
The ground wire disconnection detection circuit 2 detects whether the closed loop CL is closed or not closed. When the closed loop CL is not closed, the input voltage Vi from the power supply 16 to the high voltage generation circuit 11 or the device under test 3 is detected. The supply of the output voltage Vo is cut off.

Next, the operation of the high voltage generator according to the present invention will be described with reference to FIG. High voltage generation circuit 11
Generates a high-voltage output voltage Vo by boosting the input voltage Vi supplied from the power supply 16. Output terminals 12, 13
Is connected to the high voltage generation circuit 11 and supplies the output voltage Vo to the device under test 3. As a result, a high voltage generator that supplies a high voltage to the device under test and performs insulation resistance measurement, withstand voltage test, and the like can be obtained.

The ground wire disconnection detection circuit 2 includes a housing terminal 14,
Housing 10, housing terminal 15 and two different ground points E1,
It is detected whether the closed loop CL including E2 in series is closed or not closed, and when the closed loop CL is not closed, the input voltage Vi from the power supply 16 to the high voltage generation circuit 11 is detected.
Alternatively, since the supply of the output voltage Vo to the device under test 3 is cut off, the disconnection of the ground lines 23 and 24 can be automatically detected and the voltage supply line can be cut off. Therefore, when the worker neglects to connect the ground lines 23 and 24, the high voltage generation circuit 11 does not generate the high voltage Vo, and the high voltage generation circuit 11 applies the high voltage Vo to the device under test 3. Since there is no need to supply it, fool proofing and pokayoke are possible, and a high-voltage generator with high safety can be obtained.

Since the closed loop CL forming the ground wire disconnection detection circuit 2 includes the housing terminal 14, the housing 10, and the housing terminal 15 in series, one of the housing terminals 14 and 15 is the housing 1.
If it deviates from 0, the closed loop CL is not closed. Therefore, the input voltage Vi from the power supply 16 to the high voltage generation circuit 11 is
Alternatively, the supply of the output voltage Vo to the device under test 3 is cut off. Therefore, the input voltage Vi is not supplied from the power supply 16 to the high voltage generation circuit 11 or the output voltage Vo is supplied to the device under test 3 in a state where the housing 10 is floated from the ground. It is possible to prevent an electric shock accident due to the disconnection of the grounding of the housing.

Since the closed loop CL constituting the ground wire disconnection detection circuit 2 includes two different ground points E1 and E2 in series, when the ground rod is out of ground at either one of the ground points E1 and E2, The closed loop CL does not close. Therefore, the input voltage Vi from the power supply 16 to the high voltage generation circuit 11 is
Alternatively, the supply of the output voltage Vo to the device under test 3 is cut off. Therefore, with the ground points E1 and E2 floating from the ground, the power supply 16 supplies the input voltage Vi to the high voltage generation circuit 11 or outputs the output voltage Vo to the device under test 3.
Therefore, it is possible to prevent an electric shock accident from occurring in the non-grounded state.

Since the housing terminal 14 and the ground terminal 21 are connected to two different ground points E1 and E2 to form a dual system ground, the ground wire disconnection detection circuit 2 operates and the device under test 3
Even when the accumulated charge remains in the high-voltage generator A or the device under test 3 when the supply of the output voltage Vo to the high-voltage generator A or the device under test 3 remains, It can be grounded through either the housing terminal 14 or the ground terminal 21, and an electric shock accident can be prevented.

The output terminal 13 and the housing terminal 15 can be shared. In this embodiment, the number of connection points is reduced, and a high voltage generator with less disconnection failure can be obtained.

In the embodiment, the ground wire disconnection detection circuit 2 includes a verification signal generation circuit 25, which supplies the verification signal S1 to the closed loop CL, and the closed loop CL is closed based on the verification signal S1. It detects whether it is open or not closed. For example, when the current based on the verification signal S1 is flowing, it is detected that the closed loop CL is closed, and when the current is not flowing, it is detected that the closed loop CL is not closed. The current based on the verification signal S1 can be easily detected by a current detection resistor, a current probe or the like (not shown). Therefore, it is possible to obtain a high-voltage generator capable of easily detecting the disconnection of the ground wire.

Further, the verification signal generation circuit 25 of the embodiment is
An AC verification signal S1 is supplied to a loop including two ground points E1 and E2 of the closed loop CL. Therefore, the contact state between the grounding rod and the ground can be kept good, and the electrolytic corrosion of the grounding rod due to the electrolysis action, which is likely to occur when a direct current is passed, can be prevented.

Further, the ground wire disconnection detection circuit 2 of the embodiment is
The relay 26 is included, the winding of the relay 26 is inserted and connected in the closed loop CL, and the contacts R1 and R2 of the relay 26 are inserted and connected to the supply lines of the input voltage Vi and the output voltage Vo of the high voltage generation circuit. Therefore, when the closed loop CL is closed, a current based on the verification signal S1 flows, the winding of the relay 26 is excited, the contacts R1 and R2 are turned on, and the input voltage Vi and the output voltage of the high voltage generation circuit 11 are increased. The Vo supply line becomes conductive. When the closed loop CL is not closed, the current based on the verification signal S1 does not flow, and the relay 26
Is not excited, the contacts R1 and R2 are opened, and the supply lines of the input voltage Vi and the output voltage Vo of the high voltage generation circuit 11 are cut off. Thereby, the disconnection of the ground lines 23 and 24 can be easily detected. Further, when the closed loop CL is not closed, de-energizing the winding of the relay 26
Higher fail-safe performance. Therefore, it is possible to obtain a high voltage generator having a high fail-safe property.

As described above, the disconnection of the ground lines 23 and 24 is automatically detected and the supply line of the input voltage Vi or the output voltage Vo of the high voltage generation circuit 11 is cut off. It is possible to obtain a high voltage generator capable of preventing an electric shock accident when an acceleration test is performed by raising the temperature.

FIG. 2 is a block diagram showing the configuration of another embodiment of the high voltage generator according to the present invention. In the figure, the same reference numerals as those in FIG. 1 denote the same components.

The check signal generating circuit 25 includes a transformer T1, and the primary winding Ta of the transformer T1 has input terminals 17 and 1.
The secondary winding Tb is inserted and connected in the closed loop CL. In this embodiment, it is possible to easily obtain the low-voltage verification signal S1 that does not cause an electric shock, and to obtain the high-voltage generation device that is less expensive.

FIG. 3 is a block diagram showing the configuration of still another embodiment of the high voltage generator according to the present invention. In the figure, the same reference numerals as those in FIGS. 1 and 2 denote the same components.

In this embodiment, the verification signal generating circuit 25 includes a transformer T1 and a full wave rectifying circuit FWR. The full-wave rectifier circuit FWR is connected on the input side to a series circuit of the secondary winding Tb of the transformer T1, the ground terminal 21, the housing terminal 14, and the housing 10, and on the output side of the housing 10, the housing terminal 14, and the ground wire. Three
6, the input terminal 34, the iron core 32, the ground terminal 35, the connection terminal 22, and the relay 26 are connected to a series circuit. The relay 26 is a DC relay. As a result, the same effect as the above embodiment can be obtained. Also, the ground point E
Since the currents flowing through 1 and E2 are alternating currents, electrolytic corrosion of the ground rod does not occur.

A high voltage test apparatus according to the present invention will be described with reference to FIGS. The high-voltage test apparatus according to the present invention includes a device under test 3 and a high-voltage generator A. As the high voltage generator A, the high voltage generator according to the present invention described above is used.

The device under test 3 has a pair of input terminals 33, 3
4 and at least one ground terminal 35. The input terminal 33 is connected to the output terminal 12 of the high voltage generator A via a connection line 38. The input terminal 34 is the ground wire 3
It is connected to the output terminal 15 of the high voltage generator A via 6. The ground terminal 35 is provided at a position different from the input terminal 34 connected to the output terminal 15 of the high voltage generator A in the housing 32, and is electrically connected. The ground terminal 35 is connected to the connection terminal 22 of the high voltage generator A via the ground wire 37.

The ground wire disconnection detection circuit 2 includes a housing terminal 14,
Case 10, case terminal 15, ground terminal 35 of device under test 3
And a closed loop CL including two different ground points E1 and E2 in series.

Therefore, all of the features and advantages of the high voltage generator according to the present invention can be obtained, the disconnection of the ground line can be automatically detected, and the high voltage test device which can operate only in a completely grounded state. Can be obtained.

[0040]

As described above, according to the present invention, the following effects can be obtained. (A) It is possible to provide a high voltage generator that can operate only in a completely grounded state and a high voltage test device using the same. (B) It is possible to provide a high-voltage generator capable of automatically detecting disconnection of a ground wire and a high-voltage tester using the same.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a high voltage generator according to the present invention and a high voltage test apparatus using the same.

FIG. 2 is a block diagram showing the configuration of another embodiment of the high voltage generator according to the present invention.

FIG. 3 is a block diagram showing the configuration of still another embodiment of the high voltage generator according to the present invention.

[Explanation of symbols]

 A high voltage generator 10 housing 11 high voltage generation circuit 12, 13 output terminal 14, 15 housing terminal 16 power supply 17, 18 input terminal 2 ground wire disconnection detection circuit 21 ground terminal 22 connection terminal 23, 24 ground wire 25 inspection Signal generating circuit 26 Relay 3 Device under test 31 Coil 32 Iron core 33, 34 Input terminal 35 Grounding terminal 36, 37 Grounding wire 38 Connection line Vi Input voltage Vo Output voltage CL Closed loop S1 Check signal E1, E2 Grounding point T1 Transformer Ta Transformer 1 Secondary winding Tb Transformer secondary winding R1, R2 Relay contact FWR Full wave rectifier circuit

Claims (8)

[Claims] 1. A high voltage generating circuit, a pair of output terminals,
A high voltage generator including two housing terminals and a ground wire disconnection detection circuit, wherein the high voltage generation circuit is housed inside an electrically conductive housing and is supplied with an input voltage from a power supply. Is to generate a high-voltage output voltage, the output terminal is connected to the output side of the high-voltage generation circuit, to supply the output voltage to the device under test, the housing The terminals are mechanically and electrically connected to the housing at different positions, and the ground wire disconnection detection circuit includes one of the housing terminals, the housing, the other of the housing terminals, and 2 Completed by constructing a closed loop including three different ground points in series, detecting whether the closed loop is closed or not,
A high-voltage generator that cuts off the supply of an input voltage from the power supply to the high-voltage generation circuit or an output voltage to the device under test when the closed loop is not closed. 2. The high voltage generator according to claim 1, wherein one of the output terminals and the other of the housing terminals are shared. 3. The high voltage generator according to claim 1, wherein the ground wire disconnection detection circuit includes a verification signal generation circuit,
A high voltage generating device, wherein the verification signal generation circuit supplies a verification signal to the closed loop, and detects whether the closed loop is closed or not based on the verification signal. 4. The high voltage generator according to claim 3, wherein the verification signal generation circuit supplies an AC verification signal to a loop including at least the two ground points in the closed loop. Voltage generator. 5. The high voltage generator according to claim 4, wherein the verification signal generating circuit includes a transformer, and a primary winding of the transformer receives an AC power supply and a secondary winding A high voltage generator inserted and connected in the closed loop. 6. The high voltage generator according to claim 3, wherein the ground wire disconnection detection circuit includes a relay, and a winding of the relay is inserted and connected in the closed loop. The high voltage generator in which the contact of is connected to the supply line of the input voltage or the output voltage of the high voltage generation circuit. 7. A high voltage test apparatus including a device under test and a high voltage generator, wherein the high voltage generator is any one of claims 1 to 6. 8. The high-voltage test apparatus according to claim 7, wherein the device under test has a pair of input terminals and at least one ground terminal, and the input terminal has the high-voltage generating device. The ground terminal is connected to the output terminal of the device, and the ground terminal is one of the output terminals of the high voltage generator of the input terminals.
Is provided at a position different from the input terminal connected to one of the two, and is electrically connected, the high-voltage generator and the device under test are connected so that the ground wire disconnection detection circuit is formed. The ground wire disconnection detection circuit is configured by a closed loop including one of the housing terminals, the housing, the other of the housing terminals, the ground terminal of the device under test, and two different ground points in series. High voltage test equipment.