Touch the sensor ... the alarm circuit is enabled by T1 and T2. Transistors T3and T4 form a complimentary pair amplifier, with positive feedback (regeneration) provided to the base of first transistor ...

General purpose circuit of the simple pressure sensor alarm is built around a couple of readily available cheap components. Working of this circuit is straight forward and self-explanatory. When the ...

He’s built a finger-mounted pulse detector using a few simple components and an Arduino. This circuit uses a method known as photoplethysmography. As blood is pumped through your body ...

A few simple components are all it takes to create an over-temperature alarm. The circuit in Figure 1 requires ... As far as the temperature sensor is concerned, the choice isn’t critical.