Browse over 10,000 Electronics Projects

LED or Lamp Flasher

LED or Lamp Flasher

Flashing frequency can be varied by changing R1 value in the 1M to 4M7 range. This circuit is very efficient when driving a small 3.2V incandescent lamp. In this case omit the LED and R3, connecting the bulb across Q2 Collector and positive supply, further reducing parts counting.
R1________1M 1/4W Resistor:
R2______100R 1/4W Resistor:
R3_______22R 1/4W Resistor:
C1________1µF 63V Electrolytic, Multilayer Ceramic or Polyester Capacitor:
D1_______LED Any type and color:
Q1____2N3906 40V 200mA PNP Transistor:
Q2____2N3904 40V 200mA NPN Transistor:
SW1_____SPST Switch:
B1________3V (Two 1.5V AA or AAA cells wired in series, etc.


Visit Here for more.