Here is the circuit diagram of a super bright LED night lamp that can be operated from the mains supply. Bridge D1 is used to rectify the AC mains voltage. The capacitor C1 and resistor R1 forms the current limiting circuit. 10 ultra bright white LEDs are wired in series to produce the required light. The n-channel FET Q1(ZVN 2106) is used to automatically switch the lamp OFF at full light. The photo cell resistance is set to be 100K at full brightness. Anything less than this 100K will instantly switch the LEDs OFF. Zener diode D2 is used to limit the peak voltage across C1 during the switching of LEDs.
- Assemble the circuit on a general purpose PCB.
- The capacitor C1 is a 0.68uF/250V Polyester capacitor.
- Capacitors C2 and C3 must be rated at least 50V.
- If 1A Bridge is not available make one using four 1N4007 diodes.