What Must todo

A very simple heat detector alarm electronic project can be designed using the UM3561 sound generator circuit and some other common electronic parts . This heat detector electronic circuit project uses a complementary pair comprising npn and pnp transistor to detect heat . Collector of T1 transistor is connected to the base of the T2 transistor , while the collector of T2 transistor is connected to RL1 relay . T3 and T4 transistors connected in darlington configuration are used to amplify the audio signal from the UM3561 ic .

Heat Detector Alarm Circuit diagram

When the temperature close to the T1 transistor is hot , the resistance to the emitter –collector goes low and it starts conducting . In same time T2 transistor conducts , because its base is connected to the collector of T1 transistor and the RL1 relay energized and switches on the siren which produce a fire engine alarm sound . This electronic circuit project must be powered from a 6 volts DC power supply , but the UM3561 IC is powered using a 3 volt zener diode , because the alarm sound require a 3 volts dc power supply . The relay used in this project must be a 6 volt / 100 ohms relay and the speaker must have a 8 ohms load and 1 watt power .

Detect the presence of fire in the world of electronics can be done by detecting changes in temperature, the presence of UV ultraviolet rays and infrared light IR. Heat Sensor pyroelectric detectors Eltec E442-3 is a heat sensor (fire) that detect the presence of infrared ray IR, and therefore often called IR-EYE.

These sensors form of Lithium Tantalate pyroelectric parallel opposed dual element high gain detector with integrated analog signal processing. These sensors can detect heat changes from -40 to +70 degrees Celsius without change siginfikan of noise and sensitivity.

To use heat sensor pyroelectric detectors Eltec E442-3, it can take a kind of cone is covered with a fresnel lens to focus the direction of the infrared ray IR. Heat sensors then pyroelectric detectors Eltec E442-3 inserted into the cone is then connected to the microcontroller. Analog output value signals which when detects heat, the sensor will cause a drastic change in output voltage.