Energy-saving switch

If the effort of chasing out channels and replastering for a complete new circuit is too much, then this circuit might help. Normal operation of the light switch gives gentle illumination (LA1). For more light, simply turn the switch off and then immediately (within 1 s) on again. The circuit returns to the gentle light setting when switched off for more than 3 s. There is no need to replace the light switch with a dual version: simply insert this circuit between switch and lamp.

Resistors:

R1 = 100

R2 = 680

Capacitor:

C1 = 4700µF 25 V

Semiconductors:

D1,D2 = 1N4001

Miscellaneous:

K1,K2,K3 = 2-way PCB terminal block, lead pitch 7.5 mm

F1 = fuse, 4AT (time lag) with PCB mount holder

TR1 = mains transformer, 12V @ 1.5 VA, short-circuit proof, PCB mount

B1 = B80C1400, round case (80V piv, 1.4A)

RE1 = power relay, 12V, 2 x c/o, PCB mount 

RE2 = miniature relay, 12V, 2 x c/o, PCB mount