A Lamp flasher circuit is perhaps, the simplest way for electronics to say ‘HELLO WORLD’ to us. It is a simple electronic circuit that provides a visual cue in the form of a flashing LED/Lamp. A Lamp flasher circuit employs a voltage source, a capacitor, and an LED/Lamp. In this project, we are going to build a simple Lamp flasher circuit using Transistors.
This simple circuit can be used to flash incandescent lamps up to a 6V rating. The circuit is ideal for making flashing beacons on automobiles and other applications like that. This circuit is also seen in practice with warning & construction signposts.
Hardware Components
The following components are required to make Lamp Flasher Circuit
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | Transistor | BC549, BC556 | 1 |
| 2. | Resistors | 100K, 15K, 1K | 1 |
| 3. | Battery | 6V | 1 |
| 4. | Lamp | – | 1 |
| 5. | Electrolytic Capacitor | 10uF | 1 |
| 6. | Breadboard | – | 1 |
| 7. | Connecting Wires | – |
BC556 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of BC556
BC549 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of BC549
Lamp Flasher Circuit
Working Explanation
This is a simple lamp flasher circuit, working on the principle of regenerative feedback. On connecting the circuit to power, the 6V DC acts as a control signal to the base of the transistor Q1. the output of transistor Q1 (BC549) now acts as the input signal for the transistor Q2.
Now the output DC signal from the collector of transistor Q1 acts as a control signal for the transistor Q2 (BC556). This triggers the collector output of the transistor Q2 and the 6V lamp starts flashing. The circuit is very portable and can easily fit in a small box.
Applications
- Applications include diverse circuits such as a micro-power low battery indicator, a lightning detector, and an off-line switching power supply.
- It also serves in devices such as micropower high voltage supply, windshield wiper controllers, lamp dimmers, police sirens, etc.
- Also used in devices such as hazard flashers & turn indicators for various automobiles & vehicles.
