JPS6225824A - Monitor for multiple power sources - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides a method for monitoring whether a plurality of power supply voltages are disconnected when a plurality of power supply voltages are used in electronic and electrical equipment. This invention relates to an improvement of a multiple power source monitoring device.

[Technical background of the invention and its problems] Conventional sterilization devices include a device that uses a number of relays corresponding to the number of power supplies to be monitored, and a device that uses a number of 7-automatic arrays that correspond to the number of power supplies to be monitored. is known.

Figure 2 shows a device using relays. +5■, +12v
, -12■, relays 11 to 13 are connected between each of these voltages and the earth.

Relay contacts 118-13a corresponding to relays 11-13
are connected in series between the earth and the control circuit 14. When power supply voltages +5■, +12■, and -12V are normally applied, relays 11 to 13 operate to close relay contacts 11a to 13a, but when at least one of the power supply voltages is disconnected, the corresponding relay contact closes. The control circuit 14 is no longer supplied with earth air. Control circuit 14
can detect this and monitor whether the power supply voltage is disconnected.

FIG. 3 shows an apparatus using a photo array. Power supply voltage +
The photo arrays 15 to 17 are connected between 5V, +12V, -12V and the detection power supply 21.
Driver circuits 18 to 20 that respectively drive circuits 17 to 17 are connected to a detection power source 21. According to this, when the power supply voltage is normal, the photo arrays 15 to 17 driven by the driver circuits 18 to 20 operated by the detection power supply 21 are turned on (lit), and when the power supply voltage is cut off, the corresponding photo arrays The power supply voltage can be monitored by detecting the off state (extinguished light).

However, among the above devices, devices using relays have the disadvantage that the relays occupy a large space, and as the number of power supply voltages to be monitored increases, the space also becomes large. In addition, in devices using photo arrays,
It is necessary to prepare a detection power supply for operating the driver circuits 18 to 20 separately from the power supply voltage to be monitored.
This had the disadvantage that the configuration was complicated. Furthermore, in any of the above devices, the configuration becomes large because one detection circuit (relay in Figure 2, photo array in Figure 3) is provided for each monitored power supply. In addition, if the individual detection circuits do not operate properly, appropriate monitoring cannot be performed, and as the number of monitored power supplies increases, reliability decreases.

[Object of the invention] - The present invention was made in view of the above-mentioned drawbacks of the conventional power supply monitoring device, and its purpose is to provide a system that does not require a separate power supply and is reliable, without increasing the size or complexity of the configuration. An object of the present invention is to provide a multiple power supply monitoring device capable of highly accurate power supply monitoring.

[Summary of the Invention] Accordingly, the present invention includes an AND circuit that generates and outputs an AND for the voltages of a plurality of monitored power supplies, and an AND circuit that operates on a voltage based on the monitored power supplies and outputs the AND circuit based on the output of the AND circuit. The above object is achieved by configuring a plurality of power source monitoring device to include monitoring means for monitoring voltage interruption of the power source.

[Embodiments of the Invention] In FIG. 1, 1 indicates a Nantes gate. One input terminal of the Nandts gate 1 is supplied with a voltage based on the power supply voltage of +5× divided by the voltage dividing resistor R1R2, and the other input terminal of the Nandts gate 1 is supplied with the voltage divided by the voltage dividing resistor R1R2.
A voltage is given from a power supply voltage of +12V divided by .

A bias voltage of +5V is applied to the output terminal of the Nandt gate 1 via a pull-up resistor R5. The output terminal of the Nandt gate 1 is connected to the base of the transistor 2 via a base resistor R6. transistor 2
Earth air is applied to the emitter of the resistor 8 through a protective resistor 8. A relay 3 is connected to the collector of the transistor 2, and -12V is applied to the relay 3 from the power supply voltage.

3a is a relay contact, and 4A and 4B are terminals for detecting opening/closing of the relay contact. A Zener diode D1 is provided in parallel with the relay 3, with its cathode connected to the collector of the transistor 2. This Zener diode D1 protects the Nandt gate 1 from applying a high voltage to the Nandt gate 1. A bias resistor R7 is connected between the -12V power supply voltage and the base of the transistor 2.

In the device configured in this way, the Nant Gate 1
If the two monitored power supply voltages on the input side of +5 and +12V and the monitored power supply voltage on the relay 3 side -12V are normal,
Since the output of the Nandt gate 1 becomes L level and the transistor 2 is turned on, the relay 3 operates and the relay contact 3a is closed.

Furthermore, when any one of the three monitored power supply voltages is disconnected, the transistor 2 is turned off depending on whether an H level signal is applied to the base of the transistor 2 or the potential difference between the collector and emitter disappears. Relay 3 stops working.

This opens relay contact 3a. Therefore, terminal 4
By detecting the opening and closing of the relay contact 3a by A and 4B, disconnection of the monitored power supply voltage can be monitored.

As described above, in this embodiment, a multiple power source monitoring device can be provided with a simple and compact configuration using one transistor, one relay, one Nandt gate, and several resistors. Note that when the number of power supply voltages to be monitored is large, the number of inputs to the Nandt gates may be increased.

In the embodiment, the on/off state of the transistor 2 is detected by the relay 3 and the relay contact 3a is monitored, but the monitoring may be performed based on the logical product of the monitored pA power supply voltages, without using this circuit. If this is done, it is possible to simplify the configuration and reduce the size.

Furthermore, since the device is operated only with the AND output and the necessary monitored power supply voltage, no special power supply is required.

[Effects of the Invention] As explained above, according to the present invention, since an AND circuit is used, the configuration can be simplified and miniaturized, and reliability can be increased because the number of parts is not as large as in the past. can. Further, the operation of the device can be guaranteed with the voltage of the monitored power supply voltage without requiring a separate power supply.

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram of an embodiment of the present invention, FIG.
Is Figure 3 a conventional multiple power supply? FIG. 2 is a block diagram of the J2 device. 1... Nant gate 2... Transistor 3.
...Relay 3a...Relay contact R1-
-R8...Resistor Dl...Zener diode agent Patent attorney Nori Chika Ken Yumukai Sanno - Figure 2 Figure 3

Claims (4)

[Claims] (1) An AND circuit that generates and outputs an AND of the voltages of a plurality of monitored power supplies, and an AND circuit that operates with the voltage based on the monitored power supplies and monitors voltage interruptions of the monitored power supplies based on the output of the AND circuit. A multiple power supply monitoring device comprising monitoring means. (2) The monitoring means includes a switching element that operates with the output of the AND circuit, and a detection circuit that operates with the voltage of the monitored power supply or the output of the AND circuit and detects the operating state of the switching element. A multiple power source monitoring device as claimed in claim 1. (3) The multiple power supply monitoring device according to claim 2, wherein the switching element is composed of one transistor. (4) The multiple power source monitoring device according to claim 2 or 3, wherein the detection circuit is one relay.