JPH058696U - Fire alarm - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a loud alarm sound at low voltage and reduce power consumption. [Structure] A dry battery E is used as a power source to detect a fire and sound A
In the fire alarm 1 that sounds, a booster circuit 12 that operates only when the alarm sound A is sounded is provided.
The alarm sound A is emitted with the output voltage of.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fire alarm.

[0002]

[Prior Art]

 Since the fire alarm has a function of detecting the occurrence of a fire and notifying people around it of the fire, it is necessary to generate a large alarm sound. However, in order to obtain a sufficient volume for a fire alarm that uses dry batteries as a power source (especially for home fire alarms), increase the power supply voltage by connecting a large number of dry batteries in series or generate a large alarm even at low voltage. There was no choice but to use an electromagnetic buzzer that produces sound.

[0003]

[Problems to be solved by the device]

 However, if many dry batteries are connected in series to increase the power supply voltage, a large number of dry batteries are required and the fire alarm cannot be downsized, and if it becomes an electromagnetic buzzer that generates a large alarm sound even at low voltage, Since the buzzer itself has a large volume and consumes a large amount of power, it is necessary to increase the capacity of the dry battery, so that the dry battery used becomes large and the fire alarm cannot be downsized.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a loud alarm sound with a small number of dry batteries and to reduce the power consumption and the dry batteries to last a long time. To provide a fire alarm.

[0005]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention provides a fire alarm that uses a dry battery as a power source to detect a fire and emits an alarm sound, by providing a booster circuit that operates only when the alarm sound is emitted, and the output of the booster circuit is output. It is characterized by sounding an alarm sound by voltage.

[0006]

[Advantage] With the above configuration, when the alarm sound is not generated, the voltage of the dry battery, which is the power source, is used as it is to detect the fire, and the alarm sound is generated when the fire is detected. In this case, the voltage booster circuit is operated to boost the voltage of the dry battery, and the alarm voltage can be sounded by the output voltage of the voltage booster circuit.

[0007]

【Example】

 An embodiment of the fire alarm according to the present invention will be described below with reference to FIG.

FIG. 1 is a circuit block diagram of a fire alarm device 1 according to the present invention, which includes four dry batteries E as power sources and a constant voltage for outputting a constant voltage even if there is a slight change in the dry battery voltage. It corresponds to a pressure circuit 10, a fire detection circuit (various types such as smoke detection method and flame detection method) 11 for detecting a fire, and a booster circuit for doubling the output voltage from the constant voltage circuit 10. The voltage doubler circuit 12, an alarm sound circuit 13 incorporating a piezoelectric buzzer (not shown) that sounds at the output voltage from the voltage doubler circuit 12, and the fire detector circuit 11 activates the voltage doubler circuit 12 when a fire is detected. It is composed of a transistor Tr as a switching element for switching.

Explaining the connection relationship, the output (approximately 6V) of the dry battery E is connected to the constant voltage circuit 10, and the output (approximately 5V) of the constant voltage circuit 10 is connected to the fire detection circuit 11 and the transistor Tr. The base of the transistor Tr is connected to the fire alarm terminal 11a of the fire detection circuit 11 via the. The output (approximately 10 V) of the voltage doubler circuit 12 is connected to the alarm sound circuit 13.

Next, the operation will be described. In a normal state where no fire occurs, the fire detection circuit 11 of the fire alarm 1 performs the fire detection operation by the output (approximately 5V) of the constant voltage circuit 10, The fire alarm terminal 11a of the circuit 11 is low. Therefore, the transistor Tr is off and the voltage doubler circuit 12 is not operating.

However, when a fire occurs and the fire alarm 1, that is, the fire detection circuit 11 detects a fire, the fire alarm terminal 11a of the fire sensor circuit 11 becomes High, and the fire alarm terminal 11a is a transistor. Since the base of Tr is set to High, the transistor Tr is turned on and the voltage doubling circuit 12 operates. Then, the voltage doubler circuit 12 supplies an alarm sound circuit 13 with approximately 10 V obtained by multiplying the input voltage (approximately 5 V) of the voltage doubler circuit 12 to the alarm sound circuit 13, and the high voltage incorporated in the alarm sound circuit 13 is necessary. A piezoelectric buzzer (not shown) that emits a large volume and is small in size and consumes low power generates an alarm sound A.

In this way, the fire alarm 1 generates a loud alarm sound A only when it is necessary to detect a fire and notify the people around it of the fire. The voltage doubler circuit 12 does not operate, and only the fire detection circuit 11, which consumes less power, operates to detect fire.

[0013]

[Effect of the device]

 Since the fire alarm of the present invention is configured as described above, it is necessary to detect a fire with a power supply voltage of about 4 dry batteries (approximately 5 to 6 V) and notify people in the surrounding area of it. Only when there is a need for a high voltage built into the warning sound circuit, it is possible to sound at a high volume, and a small size and low power consumption piezoelectric buzzer can sound the warning sound. This has the effect of providing a long-lasting fire alarm for dry batteries.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing an embodiment of a fire alarm according to the present invention.

[Explanation of symbols]

 1 Fire alarm 12 Booster circuit A Alarm sound E Dry battery

Claims (1)

[Claims for utility model registration] 1. A fire alarm that uses a dry battery as a power source to detect a fire and sound an alarm sound is provided with a booster circuit that operates only when the alarm sound is generated. A fire detector characterized by sounding an alarm sound at the output voltage.