JPS5844470Y2 - fire detector - Google Patents

Description

[Detailed description of the invention] This invention sends an alarm signal to the receiver when a fire is detected, maintains the alarm state of the detector, and activates a recovery switch that has a built-in function to restore the alarm once the alarm has been triggered. This invention relates to a fire detector designed to operate in

Conventionally, fire detectors that have a structure in which the restoration operation of a detector that has triggered an alarm can be restored at the scene by operating a built-in restoration switch are equipped with the circuit configuration shown in Figure 1, and are designed to prevent heat and smoke associated with a fire. etc., and the fire detection unit 1 is activated, which sends an alarm signal to the receiver using the line current. This is done via the contact 2a, the diode Do, and the latching relay (2-winding self-holding relay) 20 primary winding P.
The next winding P is energized and its switching contact 2a is switched as shown by the dotted line to form an electric path in parallel with the fire detection unit 1, thereby maintaining lighting of the alarm indicator lamp 30 and sending out the alarm signal. Restoration of the sensor once activated is performed via the restoration switch 4 when the restoration switch 4 is closed.
This is done by energizing the secondary winding S of the latching relay 2 and returning the switching contact 2a to its original state.

Note that D1 to D4 are diodes forming a rectifier circuit, and 5 is a transfer terminal drawn out via a diode D5.

Conventional fire detectors like this have a small number of connections per line of power and signal line drawn out from the receiver.
However, as the number of connected sensors increases, each sensor has a built-in large-capacity capacitor CO, so the charging current at power-on increases, making it necessary to increase the power supply capacity of the receiver. I need to limit the number of connected devices (・.

In addition, latching relay 2 due to discharge of capacitor C6
Since the primary winding P is energized via the switching contact 2a of the latching relay 2, the moment the primary winding P is energized and the switching contact 2a is separated, the primary winding P is energized. The bias is released, and before the switching contact 2a is completely switched, 1
Since the power is applied to the next winding P, there is a risk that the switching contact 2a may malfunction.

Furthermore, when the sensor generates an alarm, the charging voltage of the capacitor CO becomes a voltage divided by the resistance inside the receiver and the circuit resistance of the alarm indicator light 3 of the sensor, so the charging voltage is lower than in the steady monitoring state. As the number of alarms increases, the voltage received by the capacitor C6 will further decrease, so even if the recovery switch 4 is closed, there will not be enough discharge current to energize the secondary winding S of the latching relay 2. This causes a delay in that the sensor cannot be restored.

This invention was developed in view of the above, and in order to increase the number of connected sensors with a built-in recovery switch and to ensure recovery operation, the contacts of the latching relay and the recovery switch are connected without using a capacitor. It is an object of the present invention to provide a fire detector configured to hold an alarm when a fire is detected and to perform a recovery operation using a recovery switch.

Examples of the present invention will be described below based on the drawings.

FIG. 2 is a circuit diagram showing an embodiment of the fire detector according to the present invention, in which a latching relay is connected in series with the fire detection section 1 and the alarm indicator light 3, which detect heat, smoke, etc. associated with a fire and close the contacts. The primary winding P of is connected so that the primary winding P is energized by the line current at the time of alarm, and the recovery switch 6 is
It is a changeover switch having a normally closed contact terminal 6a and a normally open contact terminal 6b, and the normally open contact 2b of the latching relay is connected to the normally closed contact terminal 6a, and the secondary winding S of the latching relay is connected to the normally open contact terminal 6b. and the normally open contact 2b is 1
The secondary winding P is energized to maintain the closed state, and the secondary winding S is energized to the open state.

Furthermore, D6. D7 is a diode connected in parallel to the primary winding P and the secondary winding SK to improve responsiveness during recovery, and ZD is a constant voltage diode that stabilizes the voltage supplied to the sensor.

Next, the operation of the embodiment shown in FIG. 2 will be explained.

In a normal monitoring state, both the primary winding P and the secondary winding are de-energized, the recovery switch 6 is on the normally closed contact terminal 6a side, and the normally open contact 2b is open.

In this state, when the fire detection unit 1 detects a fire and operates, the line current flows to the receiver via the alarm indicator light 3 and the primary winding P, and the alarm indicator light 3 lights up. By energizing the next winding P and closing the normally open contact 2b, the line current flows to maintain the alarm condition regardless of the operating state of the fire detection unit 1, and the alarm indicator light 30 lights up. and maintains the energization of the primary winding P.

When the power supply to the detector that has triggered the alarm is cut off using the recovery switch on the receiver side, the fire detection unit 1 will be restored, but the secondary winding S of the latching relay will not be energized.
When power is supplied again, it returns to the alarm state.

Therefore, it is necessary to operate the recovery switch 6 at the location where the sensor is installed, and when the recovery switch 6 is switched to the normally open contact terminal 6b side, the secondary winding S of the latching relay
is energized, thus opening the normally open contact 2b.

At this time, the power to the primary winding P is cut off by operating the recovery switch 6, and then the secondary winding S is energized, so that the normally open contact 2b is opened more reliably.

Incidentally, since fire detectors are usually installed in hard-to-reach places such as ceilings, the recovery switch 6 is a reed switch that is switched by bringing a magnet close to it.

In this way, the fire detector of this invention does not use a capacitor to operate the latching relay, so the impedance when the power is turned on is high enough, and even if the number of connected detectors increases, the power capacity of the receiver is small. In other words, the number of connected sensors can be significantly increased compared to the conventional method.

Additionally, since no capacitors are used, the primary and secondary windings of the latching relay can be energized reliably.
It operates reliably even when the number of connected devices increases, and is highly reliable.

FIG. 3 shows another embodiment of the present invention, in which the secondary winding S of the latching relay is connected in series with the recovery switch 7 and provided in parallel with the fire detection section 1, and the normally open contact of the latching relay is 2b is connected in parallel to the fire detection unit 1, and further provided with a connection path that short-circuits the primary winding P of the latching relay when the recovery switch 7 is closed via the diode D8.

Note that the diode D9 determines the direction of the line current that energizes the primary winding P.

Therefore, to explain the operation of the embodiment shown in FIG.
In the steady monitoring state, the primary winding P and the secondary winding S are not energized, and the normally open contact 2b and the recovery switch 7 are also open.

When the fire detector 1 detects a fire in this state, a line current flows through the alarm indicator light 3 and the primary winding P of the latching relay, and the normally open contact 2b is held open by the energization of the primary winding P. and maintain the alarm status.

Next, the recovery operation of the alarmed sensor is as follows: When the recovery switch 7 is closed, the secondary winding S of the latching relay is energized.
At the same time, the primary winding P of the energized latching relay is short-circuited via the diode D8, and the voltage of the primary winding P is set to approximately zero volts, thereby facilitating the recovery operation.
The energization of the secondary winding S opens the normally open contact 2b of the latching relay, releasing the alarm holding state.

Similar to the embodiment shown in FIG. 2, this embodiment also does not use a capacitor, so that the number of connected sensors can be increased and the operation of reliable alarm holding and recovery can be achieved.

As explained above, the fire detector of the present invention uses a latching relay, its contacts, and a latching relay as a circuit means that maintains the alarm state by operating the fire detection section and releases the alarm state by operating the built-in recovery switch. By using only switches and no capacitors, the power consumption at power-on can be kept to a low value, and the number of sensors connected to the I line from the receiver can be reduced. In addition, the power capacity of the receiver can be reduced, making equipment more compact and economical.Also, even when the number of connected sensors is increased, alarm retention and The recovery operation becomes more reliable, and by eliminating the use of capacitors that are difficult to downsize as electrical components, it is also possible to downsize the circuit device built into the sensor or socket.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing an example of a conventional fire detector using a capacitor, Fig. 2 is a circuit diagram showing an embodiment of the present invention, and Fig. 3 is a circuit diagram showing another embodiment of the present invention. FIG. 1...Fire detection unit, 2...Latching relay, 2a...Switching contact, 2b...
Normally open contact, 3... Alarm indicator light, 4.6.7...
...Recovery switch, 6a... Normally open contact terminal, 6b... Normally open contact terminal, 5... Transfer terminal, D□~D9... ...Diode, CO...
...Capacitor, RH...High resistance, ZD...
... Constant voltage diode.

Claims (1)

[Scope of utility model registration request] A first winding of the latching relay that is energized by the line current generated by the activation of the fire detection unit, and a normally open contact of the latching relay that is closed by the energization of the first winding and maintains the alarm operation of the detector. and a recovery switch that releases the energization of the first winding and energizes the secondary winding of the latching relay to open the normally open contact. .