What happens when only a few pins of 555 is used? Still we can make circuits. Here ,is a simple Fire alarm based on IC555. The trigger pin2 is used to achieve the result in addition the VCC and Ground pins. In this design, the IC555 act like a switch to give high output. When the temperature in the Room or a device exceeds the set limit, alarm sounds.
Continue reading “Thermister based Fire Alarm. Unusual Design 4”
Excess heat in electronic devices can damage the delicate CMOS components and it is necessary to monitor the temperature in these devices. With this Five component circuit, you can monitor the temperature in the heat generating devices like CPU, Inverter, CD player, Amplifier etc. It gives a warning alarm, when the temperature inside the cabinet of the device exceeds the normal level. It uses an NTC Thermister as heat sensor. The circuit is too small enough to enclose inside the gadget.
This simple circuit can monitor the heat generating devices like Amplifier, CD player, Inverter etc. The LED in the circuit blinks when the heat inside the device increases above the preset value. To give more visual attraction, a seven segment display is also included which shows a digital display as the temperature increases.
This is the circuit of a Heat sensor that beeps when it detects heat. It is an ideal add on circuit in heat generating devices like Inverter and Amplifier. The circuit uses a NTC Thermister as Heat sensor.
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