Here the 220V AC lamp touch dimmer circuit. By only touching this touch dimmer you are able to increase the light intensity of incandescent lamps in three stages. The touch dimmer is designed all around 8-pin CMOS IC TT8486A/TT6061A especially produced for touch dimmer applications.
In the beginning, when mains switch is “on”, the lamp is “off”. Now, when you touch the touch plate, the lamp glows dimly. On second touch, the lamp provides medium light. At the third touch, the lamp is powered fully. One more touch puts off the light.
Considering that the IC is very sensitive, utilize a long wire to connect the IC towards the touch sensor. The circuit utilizes minimal external parts. For touch plate, it is possible to utilize a simple copper plate of 1cm×1cm or simply the end of the lead wire. Touch plate is joined together towards the touch detector via 820pF, 2kV capacitors C1, C2, and C3 coupled in series. Internally IC TT6061A’s touch signal is connected to the counter/decoder via a resistor and clock input CK is connected to the counter/decoder via a frequency generator.
Line frequency signal is obtained via R4 at pin 2 of IC TT6061A. At zero crossing, the triac (BT136) triggers to drive a 200W lamp.
The 6.8V power supply is obtained straight from mains through resistors R1 and R3, diode D3, capacitor C4, and zener diode and given to power input pin 3 of the IC. Capacitors C1, C2, and C3 connected between touch input pin 4 and touch plate take out the shock potential from the touch plate, so don’t change these capacitors with a single capacitor or with a capacitor of a lower voltage rating. Mains potential is available in the circuit. Needless to say, it really is high risk to touch the circuit when mains is “on”.