JPS5840794B2 - Smoke detector operation/alarm stop device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an operation/alarm stop device for a smoke detector, and is particularly suitable for use in a smoke detector that uses a battery as a power source.

Smoke detectors with built-in batteries as a power source are often used as fire alarms for general homes, etc., and these devices are required to have a battery life as long as possible, and are also designed to be more compact. things are required.

The present invention solves these problems, and embodiments thereof will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention,
FIG. 2 is a timing chart for explaining the operation of FIG. 1.

In FIG. 1, a pulse generator 1 is of a pulse sampling type in order to reduce the current consumption of the sensor, and this pulse output is applied to a smoke detection section 2 having a light emitting and receiving element.

When smoke enters the smoke detection section 2, its signal is applied to the gate electrode of the SCR via the amplifier 3 and the level detection circuit 4, respectively, and causes an alarm such as a buzzer BZ to sound.

To confirm this ringing sound and stop the alarm, it is sufficient to cut off the smoke signal, but smoke that has entered the smoke sensor does not disappear immediately, but stays for a predetermined period of time, so the If the alarm is operated repeatedly, the alarm will start operating again, thus requiring cumbersome operations such as holding down the alarm stop switch, and also contributing to wasteful battery consumption in fire alarms and the like that use batteries as a power source.

Furthermore, such smoke detectors need to be tested for operation at regular intervals, which requires a switch for the operation test. Therefore, multiple operation switches are required, making the detector larger. It is also unfavorable in terms of appearance.

The device of the present invention solves these problems at the same time, and is configured so that the alarm stop and operation test can be performed separately by operating a single switch.

In FIG. 1, a signal from the operation switch SW is applied to a binary counter 5 and a monostable multivibrator 6 in the operation/alarm stop circuit, respectively.

The output from the binary counter 5 is connected to one input terminal of the AND gate 7 and the inhibit input terminal of the inhibit circuit 8, while the output terminal of the monostable multivibrator 6 is connected to the other input terminal of the AND gate 7. It is connected to a terminal and an input terminal of the inhibit circuit 8, and is also connected to a reset terminal of the binary counter 5.

The output terminal b'' of the AND gate 7 is connected to the input terminal of the amplifier 3, and the output of the inhibition circuit 8 is connected to the input side of the level detection circuit 4 via an inverter 9.

Based on the operation of the operation switch SW for stopping the alarm,
When a single pulse (P in Fig. 2) is applied to the operation/alarm stop circuit K, an output as shown in Fig. 2a is applied from the monostable multivibrator 6 to the input terminal of the inhibition circuit 8, and therefore , an output as shown in FIG. 2C appears in the inverter 9, and is applied to the input side of the level detection circuit 4.

It is assumed that the output pulse width T from the inverter 9 is set in advance to the time required for the smoke that has entered the smoke detection section 2 to naturally disappear.

In response to the output signal from the inverter 9, the output of the level detection circuit 4 is opened and stopped for a time T, during which time the smoke in the smoke detector 2 is extinguished, and as a result, the smoke detector is not activated again. .

Also, at this time, the signal applied to the binary counter 5 is
It shall be reset when the output pulse of the monostable multi-bi break 6 is restored.

Next, we will discuss the operation test.

When the operation switch SW is operated twice within the output pulse width T of the monostable multivibrator 6, a pulse as shown in FIG. are Fig. 2 a', b'
becomes.

These two output signals a', b' are applied to an AND gate 7, the output of which (b'' in FIG. 2) is applied to an amplifier 3.

Therefore, if this value is set in advance as the operating level of the smoke detector, the alarm BZ will sound and an operation test will be performed.

In this embodiment, the operation test is performed when the operation switch SW is operated twice, but the operation test is not limited to twice.

Therefore, the binary counter 5 and the monostable multivibrator 6 are not limited to these, and may be a counting circuit or a time constant circuit, respectively.

As described above, according to the device of the present invention, it is possible to separately perform the alarm stop and operation test for smoke detectors in which smoke accumulates in the smoke detector with a single push button switch, and as a result, the current consumption can be reduced. It is extremely useful for use in household sensors, etc. that have a built-in battery as a power source, such as light reduction, simplification of operation, and miniaturization.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the smoke detector operation/alarm stop device of the present invention, and FIG. 2 is a timing chart for explaining the operation of FIG. 1. 1...Pulse generator, 2...Smoke detector, 3...Amplifier, 4...Level detection circuit, BZ...Alarm Switch, SW...Operation switch, 5...Binary counter, 6...
Monostable multivibrator, 7...AND gate 4, 8...inhibition circuit, 9...inverter, K...operation/alarm stop circuit.

Claims (1)

[Claims] 1. A smoke detector equipped with a smoke detection section that detects the intrusion of smoke, an alarm generator that sounds based on the output of the smoke detection section, and an operation switch, in which the output is maintained for a certain period of time by operating the operation switch. The operation/alarm stop circuit includes a time constant circuit and a counting circuit that counts the number of operations of the operation switch, and the alarm output of the alarm generator is stopped by the output of the time constant circuit, and the counting circuit number counting′
An operation/alarm stop device for a smoke detector, characterized in that an operation signal is applied to the smoke detector when the smoke detector is activated.