Proximity detector schematic
A very simple proximity detector electronic project can be designed using this schematic circuit . This proximity detector electronic project use a tone decoder integrated circuit ( NE567 ) that will provides a signal with a frequency about 100Khz .
This signal is fed to one sensor . The sensor can be constructed from two cooper or aluminum plates or wires or other conductive material .
When an object is placed near the sensor , the capacitance between sensor is increased . The Q1 and Q2 transistors will amplify the signal and fed it to the NE567 IC , that will make the LED1 to glow .
C8 and R4 phase shift the VCO signal from the NE567 so that the U1 can detect its own output signal .
This electronic project circuit require a 9 volts DC power supply circuit .