Here I have introduce a new circuit through this you can switch off your bed room lamp with some delay.so I suppose this may be so useful circuit for you.and also after attaching a relay for this circuit you can use this as a delay circuit.This gives 15 second delay
Parts:
C1 330nF 400V Polyester Capacitor
C2 100µF 25V Electrolytic Capacitor
C3,C5 10nF 63V Polyester or Ceramic Capacitors
C4 10µF 25V Electrolytic Capacitor
R1 470R 1/2W Resistor
R2 100K 1/4W Resistor
R3 1M5 1/4W Resistor
R4 1K 1/4W Resistor
D1,D2 1N4007 1000V 1A Diodes
D3 BZX79C10 10V 500mW Zener Diode
D4 TIC206M 600V 4A TRIAC
Q1 BC557 45V 100mA PNP Transistor
IC1 7555 or TS555CN CMos Timer IC
SW1 SPST Mains suited Switch
Note
# The delay time can be changed, changing R3 and/or C4 values.
Taking C4=10µF, R3 increases timing with approx. 100K per second ratio. I.e. R3=1M Time=10 seconds, R3=1M8 Time=18 seconds. Do test and see it.
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