The circuit shown here works from 24V DC and can flash two 24V bulbs alternatively. The circuit is nothing but an astable multivibrator operating at 1Hz and 50% duty cycle. The lamp to be flashed is connected in place of the collector resistor (Rc) of a typical design. 2N3055 transistors which are well known for their ruggedness are used here. They can handle collector currents up to 10A. So a wide range of lamps (in terms of wattage) can be connected to this circuit.
- Assemble the circuit on a good quality PCB.
- Use 24V DC for powering this circuit.
- Lamp L1 and L2 can be 24V/25W type.
- It is advised to fit the transistors with heat sinks.
- Flashing rate can be modified by adjusting the values of R1, R2, C1 and C2.