JPH028223Y2 - - Google Patents

Description

[Detailed Description of the Invention] (1) Technical Field of the Invention The present invention relates to a continuity testing circuit for electrical lines connecting circuits.

(2) Background of the Technology When diagnosing various devices, it is required not only to diagnose the operation and function of the circuits themselves, but also to conduct continuity tests on electrical lines that connect circuits. In particular, in intrusion alarm systems, automatic fire extinguishing systems, and the like, there is a possibility that electric lines may become disconnected due to human intervention or adverse conditions.

(3) Prior Art and Problems To give an example of an automatic fire extinguishing system for ducts, a detector such as a fire detector is installed in the duct or duct hood above the stove in the kitchen, and the output signal of the detector is connected to an electric wire. If a fire is detected, the fire extinguisher is activated by a drive signal from the monitoring circuit to extinguish the fire. In this case, the electric wire may be disconnected due to repair work at the installation site, etc. In addition, in such a device, as a power source for the monitoring circuit, it is inexpensive, simple, and does not require special constraints on the installation site. It is desired that batteries be used.

Conventional continuity testing of electrical lines in such devices involves, for example, connecting a resistor to the end of a monitoring circuit, constantly passing a weak current through the resistor through the electrical line, and operating a test switch to test the electrical line. monitor the current flowing through the circuit.

However, in the above method, especially when batteries are used as a power source, the power consumption of the monitoring circuit is designed to be minimized when there is no fire, taking into consideration the extremely rare occurrence of fire. However, there is a problem in that the power consumption in the resistor significantly shortens the battery life.

Further, in this device and other devices of this kind, a continuity test is performed during an operation test of the device, but there are problems in that the test time is not sufficiently shortened and the operation is not sufficiently simple.

(4) Purpose of the invention The purpose of the invention is to provide a continuity test circuit that has a simple circuit configuration, consumes little power, and can quickly and reliably test the continuity of electrical lines in equipment that is in an alert state with simple operation. It's about getting.

(5) Structure of the invention The invention includes an abnormality monitoring circuit that monitors abnormal conditions in an intruder alarm device, an automatic fire extinguisher, etc., a DC power supply, a capacitor connected in parallel with the DC power supply, and the DC power supply and the capacitor. Consists of a switch that connects the
a voltage doubler generating circuit that applies the double voltage generated by switching the switch to the electric line connected to the abnormality monitoring circuit; a display circuit that displays the conduction state of the electric line; and a voltage doubler of the DC power supply. high,
A continuity test circuit for an electric line, which conducts at a voltage lower than the sum of the voltage of the DC power supply and the voltage of the capacitor charged by the DC power supply, and includes a voltage control circuit connected in parallel with the abnormality monitoring circuit. provided.

(6) Example of the invention As an example of the invention, a continuity test circuit for electric lines in an automatic fire extinguishing system for ducts illustrated in the drawings will be described.

In the drawing, a monitoring/continuity test circuit 1 is connected to, for example, a fire detector 22 as an abnormality monitoring circuit via an electric line 21. The fire detector 22 is provided inside the duct 2 or inside the duct hood,
If a fire occurs in a duct or duct hood,
For example, it is activated by the heat of a fire, causing a short circuit between its output terminals. The electric line 21 is wired along the outer periphery of the duct, and the fire detector 22 is installed inside the duct or inside the duct hood.

The monitoring/continuity test circuit 1 includes a DC power supply 10, in this example a battery, a voltage doubler generating circuit 11, a display circuit 12 as a means for confirming continuity, and a fire monitoring circuit 13.

The voltage doubler generating circuit 11 is configured as a series circuit of a diode D, a capacitor C, and a test switch SW. When the test switch SW is in the normally closed contact NC position, it is connected in parallel with the battery 10, and the open contact is connected in parallel with the battery 10.
When switched to the NO side, it is connected in series with the battery 10.

The test switch SW is selected as the open contact NO side only during testing, but otherwise the normally closed contact NC side is selected.
Selected on the side.

The fire monitoring circuit 13 includes a coil 13a that is energized when the fire detector 22 is short-circuited, a contact 13b of the coil 13a, and a fire extinguisher drive unit 13c connected in series with the contact 13b. .

The display circuit 12 is a series circuit of a light emitting diode LED and a current limiting resistor R, and connects the connection point a between the diode D and the capacitor C in the voltage doubler generating circuit 11 and the negative side (point b) of the coil 13a in the fire monitoring circuit 13. ) is connected between.

Further, in the drawing, a voltage control circuit 3 is provided outside the duct in parallel with the fire detector 22. In the illustrated embodiment, the voltage control circuit 3 has Zener diodes ZD1 and ZD2 facing each other in series, and is non-polarized to prevent wiring errors.

The operation of the circuit shown in the drawings will be described below.

First, we will discuss the operation of the automatic fire extinguishing system. The switch SW is on the normally closed contact NC side, and the capacitor C is charged to the voltage E1 of the battery 10, which is 6V in this example. When a fire occurs in this state and the fire detector 22 is activated and sends out a short circuit output, the coil 13a is energized, and the energization of the coil 13a switches the contact 13b to the open contact NO side. As a result, the voltage charged in the capacitor C operates the fire extinguisher drive unit 13c, and the output from the drive unit operates a fire extinguisher (not shown) to extinguish the fire.

After the fire is extinguished, the coil 13 is turned off by a circuit not shown.
A is deenergized and contact 13b is returned to the normally closed contact NC side.

When no fire is detected, the battery 10 consumes power only by the leakage current of the capacitor C after charging the capacitor C to the voltage E1, which increases the lifespan of the battery 10. It is planned.

Even if a fire is detected, the drive unit 13c
Since it is only necessary to operate for a moment, the drive unit 13
c After activation, the coil 13a is deenergized by a circuit not shown, and even when a fire is detected, the coil 13a is turned off.
The current flowing through the battery 10 can be made short and the power consumption of the battery 10 can be minimized.

Next, a continuity test of the electric line 21 in such an automatic fire extinguishing system will be described. In this case, the fire detector 22 is in a state where no fire is detected, that is, the output of the fire detector is in an open state, the capacitor C is charged to voltage E1, and the switch is not activated.
The SW and contact 13b are in the positions shown.

Also, the Zener diode ZD of voltage control circuit 3
1. Breakdown voltage E2 of ZD2 is larger than E1,
It is chosen to be smaller than 2E1. In this example, E1=6V and E2=8V. or
The circuit is configured so that the LED lights up when it is biased to 8V, for example.

Switch the continuity test switch SW to the open contact NO side. As a result, the capacitor C and the battery 10 are connected in series, and the voltage between the positive electrode bus and the negative electrode bus is the sum of the voltage E1 of the battery 10 and the voltage approximately equal to E1 charged in the capacitor C, that is, approximately 2E1=
It becomes 12V. This voltage is applied to the display circuit 12 and the electric line 2.
1, applied to the voltage control circuit 3.

If the electric line 21 is conductive, a voltage of 12V is applied to the voltage control circuit 3, and its breakdown voltage E2 exceeds 8V, so the capacitor C, the display circuit 12, the electric line 21, and the voltage control circuit 3 are formed, and light is emitted. Diode LED lights up.

The lighting of this LED indicates that the electric line 21 is conductive. The lighting time of the LED is determined by the time constant of the capacitor C and the resistor R.

After confirming that the LED is lit, immediately switch the switch SW to the normally closed contact side.

If the electric line 21 is disconnected, the above circuit will not be formed and the LED will not light up.
It turns out that there is a disconnection.

This test can be performed in just a moment after the capacitor C has been charged to about voltage E1. Furthermore, after the test, the capacitor C is quickly recharged. Therefore, the test can be conducted in a short period of time, and the operating time of the automatic fire extinguishing system is hardly affected.

In addition, during this test, the power consumption of the battery 10 is only the power charged in the capacitor C,
Since all the power used for lighting the LED and conducting the continuity test is performed only by the power charged in the capacitor C, the power consumed by this continuity test is extremely small.

Furthermore, this circuit is fairly simple, easy to operate, and can reliably confirm whether the electrical line is conductive or non-conductive.

In implementing the present invention, various modifications other than those described above may be adopted. For example, although a battery is illustrated as the power source 10 in the above embodiments, various other DC power sources can be used. As the voltage control circuit 3, a Zener diode ZD1,
We have described the case where ZD2 is made to face each other to make it non-polarized, but ZD1 alone may be used, and other low voltage elements other than Zener diodes may also be used, and E1 to E2
The circuit can be constructed using a switching element having a threshold value between E1, such as a transistor or a thyristor. In addition, in the illustrated embodiment, when the fire detector 22 detects a fire
The LED also emits light (dimmer than during the test), but if you want to use the LED only to check continuity during the test,
A new interlocking switch can also be provided in series with the display circuit 12.

Furthermore, as is clear, the continuity test circuit of the present invention can be used not only for the continuity test of the electric line in the automatic fire extinguishing system for ducts of the embodiment, but also for the electric line of intruder alarm devices and other devices.

(7) Effects of the invention According to the invention, there is provided a continuity test circuit that has a simple circuit configuration, consumes little power, and can quickly and reliably test the continuity of electrical lines in devices that are in an alert state with simple operation. can get.

[Brief explanation of the drawing]

The drawing is a continuity test circuit diagram of an electric line in an automatic fire extinguishing system for ducts as an embodiment of the present invention. Explanation of symbols, 1...Monitoring/continuity test circuit, 10
...Power supply, 11...Voltage doubler generation circuit, SW...Switch, C...Capacitor, 12...Display circuit,
21... Electric line, 22... Fire detector, 3... Voltage control circuit.

Claims (1)

[Claims for Utility Model Registration] Consisting of an abnormality monitoring circuit that monitors abnormal conditions, a DC power supply, a capacitor connected in parallel with the DC power supply, and a switch that switches the DC power supply and the capacitor to a series connection, a voltage doubler generating circuit that applies a double voltage generated by switching to the electric line connected to the abnormality monitoring circuit; a display circuit that displays the conduction state of the electric line; A continuity testing circuit for an electric line, comprising a voltage control circuit connected in parallel to the abnormality monitoring circuit, the circuit being conductive at a voltage lower than the sum of the voltage of a DC power supply and the voltage of the capacitor charged by the DC power supply.