Control006

                                          

220 V Lamp Flasher
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Schematic design of 220V Lamp Flasher
Part List :
Capacitors	Resistors
C1       =    1000 μF / 25V Electrolytic Transistors Q1       = BC327 Q2       = BC337 Others PL1     = Male mains plug SK1    = Female mains socket	R1         = 100K Ω ¼W R2,R5    =     1K Ω ¼W R3,R6    =    470 Ω ¼W R4         =   12K Ω ¼W Diodes D1 - D4  = 1N4007 (1A Diode) D5         = P0102D (800 mA SCR)
Notes
Especially designed for Christmas tree lamps and replaces old thermally-activated switches. This circuit is intended as a reliable replacement to thermally-activated switches used for Christmas tree lamp-flashing. The device formed by Q1, Q2 and related resistors triggers the SCR. Timing is provided by R1,R2 & C1. To change flashing frequency don't modify R1 and R2 values: set C1 value from 100 to 2200μF instead. Best performances are obtained with C1=470 or 1000μF and R4=12KΩ or 10KΩ. Due to low consumption of normal 10 or 20 lamp series-loops intended for Christmas trees (60mA @ 220V typical for a 20 lamp series-loop), very small and cheap SCR devices can be used, e.g. C106D1 (400V 3.2A) or TICP106D (400V 2A), this last and the suggested P0102D devices having TO92 case. For proper operation it's absolutely necessary to employ high Gate-sensitive SCRs.  If you are unable to find these devices you can use Triacs instead. In this case the circuit operates also with relatively powerful devices. A recommended Triac type is the ubiquitous TIC206M (600V 4A) but many others can work. Note that in spite of the Triac, diode bridge D1-D4 is in any case necessary.

Source : Electronics Lab