JPS6149718B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a battery-powered fire alarm using a battery power source such as a dry battery.

Conventionally, this type of battery-powered fire alarm has been equipped with a dead battery voltage detection means that detects a dead battery and generates an alarm to inform the user that the battery needs to be replaced. There is a problem in that you cannot know whether the battery power supply will be activated or not until the battery power supply is exhausted approximately one year after the battery power supply is installed and the voltage of the battery power supply has decreased to the battery dead detection voltage. The drawback was that it was impossible to check how much life the power supply had left.

The present invention has been made in view of the above-mentioned drawbacks.
The purpose is to provide a battery-powered fire alarm in which it is easy to confirm whether a battery exhaustion alarm is actually issued and to check the remaining life of the battery power source.

The present invention will be explained below with reference to Examples. FIG. 1 shows a circuit of one embodiment, in which a fire detection circuit section 1 causes a light emitting diode 3 to emit light intermittently using the output of an oscillation circuit 2, and a solar cell 4 provided corresponding to the light emitting diode 3 When scattered light from the light emitting diode 3 caused by smoke enters, a fire detection signal is generated via the amplifier circuit 5. The dead battery voltage detection circuit section 6 operates intermittently to flow current from the battery power supply 7, detects the battery voltage of the battery power supply 7 generated by the internal resistance R of the battery power supply 7, and detects the power supply voltage necessary for circuit operation. The battery voltage is compared with a detection level L ₀ set in advance according to the detection level L 0 , and a detection output is generated when it is detected that the battery voltage has decreased below the detection level L ₀ .
The alarm circuit section 8 is composed of a sounding device 9 such as a buzzer and a switching circuit 10, and activates the sounding device 9 when the switching circuit 10 is turned on by a fire detection signal or a detection signal from the dead battery voltage detection circuit section 6. to issue an alarm of fire or dead battery. In this case, the battery depletion detection signal is a continuous signal, and the fire detection signal is an intermittent signal, so that each alarm sound is different so that they can be distinguished. The dead battery voltage check section 11 connects the battery power source 7 and each circuit section 1, 6,
8, the common terminal C is connected to each circuit section 1, 6, and 8 side, and each contact r ₂ to _{r o} except one set of contacts r ₁ Resistance to R ₁
-Rn are respectively connected to the battery power source 7 side through these resistors _R1 to Rn, and the rotary switch RS is connected to the respective contacts _r2 to _r0 and directly connected to the contact _r1 . The respective resistance values of the resistors R ₁ to Rn are set so that the resistance values increase sequentially, and when the rotary switch RS is connected to the contact r ₁ , the battery power supply 7 directly connects each circuit section 1, 6 and 8, and when the contacts r ₂ to _{r o} are sequentially switched, a voltage drop occurs due to the connected resistors R ₁ to Rn, and the voltage obtained by subtracting this voltage drop is applied to each circuit section 1, 6, 8 will be applied.

However, under normal conditions, the rotary switch RS of the dead battery voltage check section 11 is closed to the contact _r1 . In this case, the voltage of battery power supply 7 is at the detection level.
When the voltage drops to L ₀ , the dead battery voltage detection circuit section 6 detects this drop and activates the alarm circuit section 8 to issue a warning that the battery is dead.

Now, if you want to check whether or not an alarm is actually issued during use, turn the rotary switch RS one after another. That is, when the voltage obtained by subtracting the voltage drop Ri Ii due to the connected resistor Ri is set to the detection level L ₀ of the dead battery voltage detection circuit section 6, the dead battery voltage detection circuit section 6 detects this. to activate the alarm circuit section 8. where each resistor R ₁
~Battery power supply 7 where any one voltage among the voltages subtracting the voltage drop of Rn from the battery voltage is close to the dead battery.
Even if it is a new battery power source 7,
By setting each resistance value so that the detection level is L ₀ as shown in Figure 2, the alarm will not sound even if the contacts r ₂ to r _o of rotary switch RS are switched. In this case, a circuit failure can be detected.
At the same time, the remaining life Ti of the battery power source 7 can also be determined from the resistor Ri switched and connected to the circuit.

FIG. 3 shows another embodiment of the present invention, in which a constant resistor R ₀ is inserted in series in the power supply path, and both ends of the constant resistor R ₀ are connected in the opposite direction to the electrode direction of the battery power source 7. It uses a dead battery voltage checking section 11 that selectively applies voltages to each circuit section 1, 6, and 8 so as to apply a set voltage _V0 , and the dead battery voltage detection circuit section 6 The remaining life of the battery power source 7 can be checked based on the value of the set voltage V ₀ when the battery operates.

The present invention is configured as described above, and includes a battery power source,
A dead-battery voltage checker is installed in the power supply path connecting the fire detection circuit, dead-battery voltage detection circuit, and alarm circuit, so that the voltage of the battery power source can be selectively lowered in multiple stages. can be arbitrarily set to the voltage when the battery is dead, and therefore it is possible to actually generate a dead battery alarm at any time, making it easy to check the operation of the circuit, and setting the battery dead voltage check section. The effect is that the remaining life of the battery power source can be known just by determining the contents.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of one embodiment of the present invention, FIG. 2 is an explanatory diagram of the same operation as above, and FIG. 3 is a circuit diagram of another embodiment of the present invention. A dead battery voltage detection circuit section, 7 a battery power source, 8 an alarm circuit section, and 11 a dead battery voltage inspection section.

Claims (1)

[Claims] 1. A fire detection circuit section driven by battery power;
A dead battery voltage detection circuit section that intermittently detects the voltage of the battery power supply and generates a detection output when the detected voltage drops to a certain level, and a dead battery voltage detection circuit section that detects the voltage of the battery power supply intermittently and generates a detection output when the detected voltage drops to a certain level. In a battery-powered fire alarm having an alarm circuit section driven by A battery-powered fire alarm characterized by being provided with a dead battery voltage checking section that selectively lowers the voltage in multiple stages in a pseudo manner.