JPH0480342B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention detects whether or not a voltage is being applied to a high potential part of an electrical device using an antenna placed at a certain distance from the high potential part. This invention relates to a voltage detector that makes decisions based on electrostatically induced potential.

[Prior Art] This type of conventional device uses a circuit to improve operational reliability, for example, as in the voltage detector disclosed in Japanese Patent Publication No. 62-53780 (Japanese Unexamined Patent Publication No. 54-150172) filed by the present applicant. Because the two systems are duplicated and OR is taken at important points, the two systems operate in the same way for the same input, and the fault detection circuit configuration means that a failure occurs only when the two systems do not operate in the same way. Output.

[Problem to be solved by the invention] Therefore, in the case of a failure that causes two systems to operate in the same way (for example, an electric circuit drive power source other than the power source required to drive a relay; when a circuit stops operating due to a failure), it is considered a failure. The drawback was that there was no failure output even though there was.

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional system, and in order to improve the reliability of operation, the circuit is tripled, and the operation of the three systems is outputted by majority voting. The object of the present invention is to provide a voltage detector in which a fault detection circuit is made to operate reliably in the case of any fault by inverting the logical operation of one of the three systems to the other two systems. That is.

[Means for Solving the Problems] In order to achieve the above object, the present invention detects whether or not a voltage is applied to a high potential part of an electrical device by detecting an induced voltage from the high potential part. In a voltage detector having a system for comparing the voltage with a reference voltage in a comparison circuit, three systems are provided in parallel, each system receives a signal from the comparison circuit, and each system has one output circuit. a majority decision processing circuit that receives signals from these output circuits and performs majority decision processing to determine whether or not a voltage is applied to the high potential section; and a failure detection circuit for determining whether there is a failure in any of the systems, and the outputs of two of the three comparison circuits have a logic opposite to that of the other comparison circuits. The output circuit is configured to output an output and input it to the majority processing circuit, and the majority processing circuit is composed of relay contacts of each output circuit, and the relay contact output constitutes an OR circuit in combination with the contacts of each output circuit. and each of the output circuits is a relay drive circuit including a relay, and each of the output circuits is a relay drive circuit including a relay, and the relays in some output circuits connected to the some comparison circuits and the other The relays in the other output circuits connected to the comparison circuit operate in the opposite direction, and the several output circuits and the other output circuits output the same contact signal of opening or closing the relay. The present invention aims to provide a voltage detector that can

[Embodiments of the Invention] The present invention will be explained in detail below with reference to the figures.
FIG. 1 shows the configuration of a device according to an embodiment of the present invention. In the figure, 1 is an antenna placed at a certain distance from an electrical device, 2 is a coaxial antenna cable, 3a and 3b are capacitors, 4
a, 4b and 4c are detection resistors, 5a, 5b and 5c are amplifier circuits, 6a, 6b and 6c are rectified wave circuits, 7a, 7b and 7c are reference voltage generation circuits, 8a, 8b and 8c are comparison circuits, 9a,
9b and 9c are relays and relay drive circuits,
10 is a failure detection circuit; 11 is a majority processing circuit that processes and outputs information from three systems; 12 is a power supply;
13 is a charging indicator lamp (LED) that is displayed when the high potential part is charging; 14 is a non-charging indicator lamp (LED) that is displayed when the high potential part is not charging; 15 is a check switch for this device; 16 is the voltage source for inspection.

Next, the operation will be explained. When a voltage is applied to a high potential part of an electrical device, a current flows through the antenna 1 due to the capacitance between the high potential part and the antenna 1, which is arranged at a certain distance. This current passes through capacitors 3a and 3b to detection resistors 4a,
A flowing voltage is generated across 4b and 4c. This voltage is amplified by amplifier circuits 5a, 5b and 5c of the first, second and third systems, and then rectified wave circuit 6 of the first, second and third systems.
a, 6b and 6c, respectively, and these converted DC voltages are compared with DC reference voltages generated by reference voltage generation circuits 7a, 7b and 7c, respectively, and comparison circuits 8a and 8b.
and 8c. If a voltage is applied to the high potential part of the electrical equipment, the rectifier wave circuit 6
If each of the DC voltages from a, 6b and 6c is larger than the reference voltage from the reference voltage generation circuits 7a, 7b and 7c, the comparison circuits 8a, 8b and 8c are compared to the comparison circuits 8a and 8b of the first and second systems. outputs a positive voltage, and the comparator circuit 8c of the third system outputs a negative voltage.
Such an operation when a voltage is applied to a high potential part of an electric device is hereinafter referred to as a charging operation. Conversely, if no voltage is applied to the high potential part of the electrical equipment, the comparator circuits 8a and 8b output a negative voltage, and the comparator circuit 8c outputs a positive voltage, and this operation is performed. This is referred to as non-charging operation below.

Relays and relay drive circuits 9a, 9b and 9c are operated by the outputs of comparison circuits 8a, 8b and 8c, respectively. The mode of this operation is, for example, as follows. When the bus bar, that is, the high potential part of the electrical equipment is used for charging, the comparator circuits 8a and 8b
The positive voltage output from the circuits operates relays RLa and RLb (FIGS. 2 and 3) in circuits 9a and 9b, causing contacts Ca and Cb to collapse into A contacts. Since the relay RLc (FIGS. 2 and 3) in the circuit 9c does not operate due to the negative voltage output from the comparator circuit 8c, the contact Cc remains in the B contact position.

Conversely, when the bus bar is not charging, the circuit 9a
Relays RLa and RLb in circuit 9b do not operate, and relay RLc in circuit 9c operates.

In this way, the relays RLa, RLb, and RLc are activated, activated, and inoperative when charging, and inactivated, inactive, and activated when not charged, and the majority decision processing circuit 11 receives the contact signals of these relays. Then, it is determined whether to charge or not to charge based on the operation of the three systems, that is, the majority vote. When the circuit 11 determines charging, it lights up the charging indicator lamp 13, and when it determines that it is not charging, it lights up the non-charging indicator lamp 14, and outputs these signals without voltage (not shown).
It also comes out depending on the situation.

Therefore, even if one component in this device fails and operates in the opposite direction to the input information, the other two systems are operating normally, so the failed system is ignored, and the device outputs the two normal systems. It works. in this case,
The failure detection circuit 10 detects that there is a system that has failed, and notifies the user that there is a component failure and calls for attention.

The failure detection mode of the failure detection circuit 10 is as follows. That is, as mentioned above, if there is no failure, the relays RLa, RLb, in the circuits 9a, 9b, 9c
RLc is in one of two states: active, active, non-active (if charging), or non-active, non-active, active (if not charging). These relays RLa,
Failure detection circuit 10 by contact signals of RLb and RLc
outputs a signal indicating a failure when these relays are in a state other than the two described above.

An example of such a circuit is shown in FIG. Figure 2 shows the case of charging, and the relay
RLa, RLb, and RLc are in operation, operation, and non-operation. Therefore, relay RLx in fault detection circuit 10
is in working condition. Relay becomes non-charging
It can be seen that even if RLa, RLb, and RLc become inactive, inactive, or active, relay RLx remains in the active state.

If a failure occurs in the first system, for example somewhere at 3a, 5a, 6a, 7a, 8a in Figure 1, only relay RLa will be inoperative and contact Ca
If the relay RLx falls to the B contact, the circuit of the relay RLx is not configured and no current flows, so it becomes inoperable, and a failure signal is output through that contact. The same applies to Figure 3.

Furthermore, with the configuration shown in FIG. 2, if the power supply system fails, relays RLa, RLb, and RLc will operate in the same way, and therefore relay RLx will be inactive and similarly output a failure signal.

[Effects of the Invention] As described below, according to the present invention, the reliability of the circuit operation is increased by triplicating the system and performing majority decision processing on the output, and the presence or absence of abnormality in the device is detected by the constantly monitoring failure detection circuit. Can be output correctly to the user.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a voltage detector according to an embodiment of the present invention, and FIG. 2 is a circuit diagram showing internal parts of a relay drive circuit and a failure detection circuit.
FIG. 3 shows the circuit configuration of the majority decision processing circuit 11. In the figure, 1 is an antenna, 5a, 5b, 5c
is an amplifier circuit, 6a, 6b, 6c are rectifier wave circuits,
7a, 7b, 7c are reference voltage generation circuits, 8a, 8
b and 8c are comparison circuits; 9a, 9b, and 9c are relays and relay drive circuits (output circuits); 10 is a failure detection circuit; and 11 is a majority decision processing circuit.

Claims (1)

[Claims] 1. In a voltage detector having a system for comparing the induced voltage from the high potential part with a reference voltage in a comparison circuit in order to detect whether or not a voltage is applied to the high potential part of the electrical equipment, The system is 3 in parallel.
one output circuit for each system that receives signals from the comparison circuits in each system, and a voltage is applied to the high potential section by receiving signals from these output circuits and performing majority voting processing. a majority decision processing circuit that determines whether or not the output circuit is in operation, and a failure detection circuit that also receives a signal from the output circuit and determines whether there is a failure in any of the three systems, Two of the three comparison circuits
The output of one comparison circuit is configured to output a logic output opposite to the output of the other comparison circuit, and is input to the majority decision processing circuit, and the majority decision processing circuit is composed of relay contacts of each output circuit. and the relay contact outputs are ORed in combination with each output circuit contact.
configuring circuits, configuring them in series, and each of the output circuits being a relay drive circuit including a relay, the relays in the several output circuits being connected to the several comparing circuits; The relays in the other output circuits connected to the other comparison circuits operate in the opposite direction, and the several output circuits and the other output circuits output the same contact signal of opening or closing of the relays. A voltage detector characterized by: