Touch-Controlled Lamp Dimmer

This is a three-modes lamp dimmer circuit with touch control. This circuit can be used to control a lamp in 3 operation modes: dim, off, and bright. A NE555 timer is used to generate a one-second pulse when we touch the touch plate. The human body produces ambient ac fields which will be used to trigger the NE555. An input network is made from D1 and C1. Here is the schematic diagram of the  circuit:

This circuit also uses a 4017 decode divider/counter to drive one of 10 outputs. The resistor is connected in series with LED in the optocoupler which control the a triac. This triac will be connected to the load such as lamp, heater, or other passive devices. The brightness levels of this circuit is configurable up to 10. The resistor and IN914 should be needed for each output. U3 MOC3010 isolate the high voltage and the low voltage section, so you won’t be shocked by high voltage when touching the touch plate. [Circuit’s schematic diagram source: seekic.com]