SIMPLE TOUCH SWITCH

SIMPLE TOUCH SWITCH

This is a simple touch switch which uses a silver pad for the touch to the base of the Q1

CIRCUIT DIAGRAM

 


PARTS LIST

R1 22Meg resistor
R2 47K resistor
R3,R4 100K resistor
R5,R6,R7 2K2 resistor
C1 Capacitor, 22μF, 25V
C2 Capacitor, 22μF, 25V
Q1 MPF102
Q2,Q3 2N3565
Q4 TIP31
La1 Bulb, #53



NOTES:

The MPF102 (Q1) can be replaced with a NTE451 or ECG451, but still
widely available. JFET-N-CHAN, UHF/VHF AMP
The 2N3565 (Q1/Q2) can be replace with a 2N2222(A), BC107, BC108,
BC109(A/B/C), NTE123A, or ECG123A.
The TIP31 (Q3) can be replaced with a NTE196 or ECG196, but is a
common type and widely available. NO suffix.
The 'Touch Plate' can be anything non corrosive. I use a silver quarter.
You can also use a small relay instead of the #53 bulb.