Heat Sensor

Here is a simple circuit which can be used as a heat sensor. In the following circuit diagram thermistor and 10K Ohms resistance is connected in series and makes a potential divider circuit . If thermistor is of N.T.C (Negative temperature Coefficient ) type then after heating the thermistor its resistance decreases so more current […]
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Four Tone Siren

Circuit Diagram of Four Tone Siren UM3561 Project Picture UM3561 IC includes ¬†oscillator and selector circuits so few external component is used for construction of four tone siren. The UM3561 contains programmed mask ROM to simulate siren sound. Power consumption of IC is low. It is powered by 3 Volt. One NPN Transistor is used […]
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