Category «Bio and Medical»

Single Cell 1.5V Hearing Aid

This is a hearing aid circuit with 1.5v supply. This circuit is used to detect very faint sounds, then deliver the sounds to an 8 ohm earpiece. This circuit requires 1.5v input voltage, need only a single cell battery. Here is the schematic diagram of the circuit: This circuit can be assembled in a small …

Simple Lie Detector

Simple Lie Detector_jadi

To know someone is lying  or not we can use lie detector. This is a simple lie detector that can be made in minutes. It works to detect the someone who telling lie but it is not as sophisticated as the ones the professionals use. Here is the schematic diagram of this circuit: The skin …

Heartbeat Sensor (Tranduscer)

heart-beat-detector

To build a heart-beat transducer not as difficult as imagined. Circuit below shows a simple heart-beat transducer. This circuit made from an infrared phototransistor and infrared LED.  This transducer works with the principle of light reflection,in this case the light is infrared.  The skin is used as a reflective surface for infrared light. The density …