230Vac Lamp Toggle Switch Circuit

Compact, transformerless circuitry No relays employed

Due to the low current drawing, the circuit can be supplied from 230Vac mains without a transformer. Supply voltage is reduced to 12Vdc by means of C1 reactance, a two diode rectifier cell D1 & D2 and Zener diode D3. IC1A, IC1B, R2, R3 and C3 form a reliable bounce-free toggle switch operated by P1. R4 and C4, wired to pin #6 of IC1B reset the circuit (lamp off) when power supply is applied. IC1C and IC1D wired in parallel act as a buffer, driving the Gate of the Triac through R5.

Circuit Diagram :

230Vac Lamp Toggle Switch Circuit diagram

Parts:

R1____________470R   1/2W Resistor
R2_____________10K   1/4W Resistor
R3,R4_________100K   1/4W Resistors
R5______________1K   1/4W Resistor

C1____________330nF 400V Polyester Capacitor
C2____________100µF   25V Electrolytic Capacitor
C3____________100nF   63V Polyester or Ceramic Capacitor
C4_____________10µF   25V Electrolytic Capacitor

D1,D2________1N4007 1000V 1A Diodes
D3_________BZX79C12   12V 500mW Zener Diode
D4__________TIC206M 600V 4A TRIAC

IC1____________4011 Quad 2 Input NAND Gate CMos IC

P1_____________SPST Pushbutton

Note:

he circuit can be wired permanently to the mains supply as current drain is negligible.

Due to transformerless design there is no heat generation.

Low Gate-current Triacs are recommended.

Obviously, other appliances can be powered in place of a lamp, provided their power dissipation does not exceed about 400W @ 230V

110-120Vac operation is easily obtained by simply changing C1 value to 680nF 250V. No further changes are necessary.

In some cases, e.g. when the controlled device is far from the toggle switch, a pilot LED could be necessary for monitoring purposes. If so, disconnect pin #10 of IC1C from pin #11 of IC1D and wire a LED and its 1K series current limiting resistor across pin #10 of IC1C and negative supply.

Warning! The circuit is connected to 230Vac mains, so some parts in the circuit board are subjected to lethal potential! Avoid touching the circuit when plugged in and enclose it in a plastic box.

Source: www.redcircuits.com