JPS6349819Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a fire detector that changes the color of the alarm indicator light according to the analog detection level of physical phenomena in the surrounding environment such as temperature and smoke density due to the occurrence of a fire. .

In conventional fire detectors, when the detection level reaches a preset threshold, a fire detection signal is sent to the receiver, an alarm indicator using a light emitting diode, etc. is turned on, and the fire detector is activated. We are making sure that any notifications are made on the spot. For this reason, when testing the operation of a fire detector, for example, in a fire detector that detects a rise in temperature due to a fire to determine a fire, the heat-sensitive part is heated with a heater etc. to give the test temperature, and when the light emitting diode lights up. , it was determined that it was operating normally.

However, it is not possible to confirm whether the fire detector is working properly until the heat-sensing part of the fire detector is heated to a nominal temperature, and the heat-sensing part reaches the set level and the light emitting diode lights up. If a problem occurs in the diode, the light-emitting diode will not light up even if the heat-sensing part of the fire detector is heated to the test temperature, causing the heat-sensing part to heat up more than necessary and causing damage to the protective cover of the fire detector. It was hot.

Furthermore, when testing the operation of a fire detector that detects temperature increases due to fire in an analog manner, it is necessary to apply several different test temperatures and conduct the test in stages. There has been a strong need for a fire detector that can immediately and easily confirm the detection status according to several types of stepwise test temperatures.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a fire detector whose operating state can be confirmed according to changes in the detection level of the fire detector.

In order to achieve this purpose, the present invention includes a light emitting diode that emits light in a safe color such as green, and a light emitting diode that emits light in a dangerous color such as red, which are installed in the sensor housing or base so that the emitted light colors are mixed. , a compensation element is provided in each light emitting diode so that the light emission amount-current characteristic of each light emitting diode changes linearly, and the light emitting ratio of the two light emitting diodes is changed according to the detection level, so that the light emission ratio of the two light emitting diodes is changed according to the detection level. The color of the emitted light changes continuously from a safe color to a dangerous color.

Hereinafter, a circuit diagram of a fire detector according to an embodiment of the present invention will be explained based on the drawings.

First, the configuration will be described. Reference numeral 1 denotes a detector that detects smoke concentration, gas concentration, temperature rise, etc., due to the occurrence of a fire. A detection signal detected by the detector 1 is input to a negative input terminal of an operational amplifier circuit 2 via a resistor R6. Meanwhile, resistors R4 and R5 are connected in series between a pair of power supply lines.
is connected to the positive input terminal of operational amplifier circuit 2, and a reference voltage determined by the divided voltage of resistors R4 and R5 is applied to the positive input terminal of operational amplifier circuit 2. The output terminal of operational amplifier circuit 2 is feedback connected to the negative input terminal of operational amplifier circuit 2 via resistor R3, and resistors R3, R4, R5, R6 and operational amplifier circuit 2 form a differential amplifier circuit that amplifies the voltage difference between the positive input terminal and the negative input terminal. Resistor R1, green light-emitting diode D1, varistor B1, resistor R2, red light-emitting diode D2 and varistor B2 are connected in series between the pair of power supply lines, and the output voltage of operational amplifier circuit 2 is fed to varistor B1.
and resistor R2, and the light-emitting diodes D1 and D2 are turned on in response to the output voltage of the operational amplifier circuit 2.
Changes the amount of light emitted by the

Here, the light emitting diode D1 is the operational amplifier circuit 2.
When the output voltage of D1 is at the base level, the maximum current flows and a green safety color is emitted, and as the output voltage of the operational amplifier circuit 2 increases, the current flowing through the light emitting diode D1 decreases, and the amount of light emitted also decreases. . On the other hand, the light emitting diode D2 increases the amount of light emitted in a red dangerous color by increasing the energizing current as the output voltage of the operational amplifier circuit 2 increases, and the output voltage of the operational amplifier circuit 2 reaches the fire detection level. When the current is reached, the current flowing through the light emitting diode 2 reaches its maximum, and the amount of red light emitted also reaches its maximum, indicating danger. Varistors B1 and B5 are compensation elements that adjust the current flowing through the light emitting diodes D1 and D2 by changing their internal resistance according to changes in the output voltage of the operational amplifier circuit 2. It has a compensation function that compensates for the amount of light emitted by changing in proportion to the output voltage of the operational amplifier circuit 2.

Further, the light emitting diodes D1 and D2 are installed in the housing or base of the fire detector in a state that they are incorporated in the same lamp cover so that the mixed colors of light emitted from the light emitting diodes can be seen from the outside.

Next, the operation of the present invention will be explained. The divided voltage of resistors R4 and R5 connected in series between the power lines is always applied to the positive input terminal of the operational amplifier circuit 2 as a constant reference voltage, and the voltage difference between the voltage and the detection signal voltage detected by the detection unit 1 is A signal voltage proportional to is output from the output terminal of the operational amplifier circuit 2. For example, if the reference voltage applied to the positive input terminal of the operational amplifier circuit 2 is set to a voltage equal to the normal signal voltage from the detection unit 1 in the normal state, the voltage between the positive input terminal and the negative input terminal of the operational amplifier circuit 2 under normal conditions Since the potential difference becomes zero, zero V is output from the output terminal of the operational amplifier circuit 2, the light emitting diode D2 is turned off, the maximum current flows through the light emitting diode D1, and it emits green light to indicate the normal state.

Next, the operation when a fire is detected will be explained. When the detection signal voltage detected by the detection unit 1 increases due to the occurrence of a fire, the potential difference between the positive input terminal and the negative input terminal of the operational amplifier circuit 2 increases, and an output voltage proportional to this potential difference is output from the operational amplifier circuit 2. It is output from the terminal, and the potential at point A increases in proportion to the detection signal voltage from the detection section 1. For this reason, barista B
1. Due to the intervention of B2, the current flowing through the light emitting diode D1 decreases in proportion to the potential change at point A and the amount of light emitted decreases, while the current flowing through the light emitting diode D2 increases and the amount of light emitted increases, resulting in a mixture. The emitted color is
The color changes from green to yellow-green, yellow, and then orange. Furthermore, when the detection signal voltage from the detection unit 1 reaches the fire detection level, a voltage equal to the power supply voltage E is applied to the operational amplifier circuit 2.
Since the potential at point A becomes the same potential as the power supply voltage, the light emitting diode D1 is turned off and the maximum current flows through the light emitting diode D2, which emits red light to indicate a dangerous situation.

As explained above, according to the present invention, a light emitting diode emits light in a safe color such as green when the detection level of the fire detector is at the base level, and a dangerous color such as red when the detection level reaches the fire detection level. By providing a light emitting diode that emits light at the same time, and by changing the ratio of the amount of light emitted from each light emitting diode in proportion to the amount of change in the detection level from the base level to the fire detection level, it is possible to The effect is that the detection operation of the fire detector can be easily confirmed from the change in the emitted light color in accordance with the change in the detection level of the fire detector.
Further, a compensation element is provided to compensate so that the light emission amount-current characteristics of the light emitting diodes are linear, and the ratio of the light emission amounts of the green and red light emitting diodes is changed linearly in accordance with the detection level of the fire detector. The operating status of the fire detector can be easily determined from the color change from green to red.

[Brief explanation of drawings]

The figure is a circuit diagram showing an embodiment of the present invention. 1...Detection section, 2...Operation amplifier circuit, R1, R
2, R3, R4, R5, R6...Resistance, D1, D
2... Light emitting diode, B1, B2... Varistor.

Claims (1)

[Scope of utility model registration request] A light emitting diode that emits a safe color when the detection level of a fire detector that detects changes in physical phenomena in the surrounding environment due to the occurrence of a fire is at the base level, and a light emitting diode that emits a dangerous color when the detection level reaches the fire detection level. and a compensation element that compensates for the light emission amount-current characteristic of each of the light emitting diodes to be linear, and the detection level of the fire detector is proportional to the amount of change from the base level to the fire detection level. and a light emitting amount changing means for changing the ratio of the light emitting amounts of the light emitting diodes, and the detection level state is displayed using a mixed color of the safe color and the dangerous color.