JPS5813955B2 - Kasaijyushinki - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention connects the emitter of a first transistor Tr1 whose collector is connected to a relay 3 to the collector of a second transistor Tr2, and connects the first and second transistors Trl,
A parallel circuit consisting of the fire detector 2 and a terminating resistor R1 is connected between the bases of the first transistor Tr2 via the sensing wiring 1, and the base of the first transistor Tr1 is connected to the power supply Vc via the bias resistor R2.
c connected to I7, the relay 3 detects an abnormality when the sensing wiring 1 is disconnected or short-circuited, or when the fire detector 1 detects a fire, and its purpose is as follows: The object of the present invention is to provide a fire receiver that automatically detects disconnections and short circuits in sensing wiring and fire detection by a fire detector as the same signal in fire alarm equipment.

The configuration of the present invention will be explained in detail below with reference to embodiment figures.

2 in the figure is a fire detector, which is designed to be electrically conductive when a fire is detected.

R1 is a terminating resistor connected in parallel to the fire detector 2.

Reference numeral 1 indicates sensing wiring, which is used when installing the fire detector 2 at a predetermined location.

The emitter of the first transistor Tr1 and the collector of the second transistor Tr2 are directly connected, and a relay 3 is connected between the collector of the first transistor Tr1 and the power supply Vcc.
is inserted and connected.

R2 is a bias resistor for applying a bias voltage to the base of the first transistor Tr1, R3 is a resistor, and D is a diode.

Next, let's examine how the output of the relay 3 changes depending on the disconnection or short-circuit state of the sensing wiring 1 and the fire detector 2.

First, if both the fire detector 2 and the sensing wiring 1 are normal,
Since both the first transistor Tr1 and the second transistor Tr2 are turned on, the relay 3 is also turned on.

However, if the sensing wiring 1 is disconnected for some reason, the first transistor Tr2 is turned on but the second transistor Tr2 is turned off, so that the relay 3 is turned off and the abnormal state is notified to the outside.

Furthermore, if the sensing wiring 1 is short-circuited for some reason, the first transistor Tr1 is in an off state because no base current flows, and even if the second transistor Tr2 is in an on state, no current flows to the relay 3. It turns off and notifies outsiders of the abnormality.

Furthermore, when the fire detector 2 detects a fire and becomes conductive, the sensing wiring 1 becomes the same state as being short-circuited, and the second transistor Tr2 is turned on, but the first transistor Tr,
is off, and the relay 3 is eventually turned off to detect an abnormality.

In the present invention, since the emitter of the first transistor whose collector is connected to the relay and the collector of the second transistor are connected, an AND circuit can be formed by the first transistor and the second transistor, and both the first and second transistors can be connected. Current will flow through the relay only when it is on, and since the parallel circuit of the fire detector and the terminating resistor is connected between the bases of the first and second transistors via the sensing wiring, the sensing wiring may be disconnected. In case of short circuit and each state of fire detection operation of the fire detector, one of the first and second transistors will be turned off, so the relay can automatically detect the abnormality, and the abnormality of the fire alarm equipment can be detected automatically. It has the effect of being easy to detect with a simple circuit configuration, and also has a first transistor that turns off when the fire detector is activated (the sensing wiring is short-circuited) and a first transistor that turns off when the sensing wiring is disconnected. A second transistor is connected in series with the relay, and two types of abnormalities caused by fire occurrence (short circuit occurrence) and disconnection occurrence are handled by one relay, so the relay is shared. This has the effect of simplifying the configuration and reducing costs.

[Brief explanation of drawings]

The drawing is an electrical circuit diagram of one embodiment of the present invention, in which 1 is a sensing wiring, 2 is a fire detector, 3 is a relay, Tr1 is a first transistor, Tr2 is a 21st transistor, R1 is a terminating resistor, and R2 is a The bias resistor and Vcc are the power supply.

Claims (1)

[Claims] 1 Connect the emitter of the first transistor whose collector is connected to the relay and the collector of the second transistor,
and a parallel circuit of a fire detector and a terminating resistor is connected between the bases of the second transistor via a sensing wiring, and the base of the first transistor is connected to a power supply via a bias resistor,
A fire receiver characterized in that a relay detects an abnormality when the sensing wiring is disconnected or short-circuited or when a fire sensor detects a fire.