Metal Human boay Touch Interface sensor module with KSP13 Transistor on board

Metal Touch Sensor Module features a KRS13 darlington NPN transistor, the signal of which is controlled by a circuit part of which integrated type LM393 inside which there are two comparators. When you touch the bare wire bent over the transistor, which is represented by the base of the transistor, the 50 Hz signal around us in a modern home or office is injected into a high gain amplifier. The output of this amplifier is connected to a comparator, the sinusoidal AC signal is then converted to a square wave. Vein sensitivity adjustment by adjusting VR1 trimmer appropriately. If you look closely at the LED you will see a slight flicker, this is due to the output that is represented by a square wave of 50 Hz instead of constant value. 

Features:

• Main chip: LM393
• Working voltage: for DC 5V
• Single-channel signal output
• Low-level output signal used for human body touch sensor alarm
• Adjustable sensitivity
• Pin Connector to board: 4 Pins