Simple 12V Single Lamp Flasher Circuit make lamp blink ON and OFF which looks cool; also this circuit is simple and strong and is good for 12V car lamps.
Furthermore, we can use this circuit for turn signals, warning lights and decorative lighting.
The circuit uses a BC557 transistor and an IRF530 MOSFET for switching and control.
Also, it works by charge and discharge capacitor to control blink time.
Circuit Working:
Parts List:
| Components | Values | Quantity |
|---|---|---|
| Resistors | 6.8k 1/4 watt | 1 |
| 220k 1/4 watt | 1 | |
| 22k 1/4 watt | 1 | |
| Capacitor | Electrolytic 100μF, 25V | 1 |
| Semiconductors | MOSFET IRF530 | 1 |
| Transistor BC557 | 1 | |
| Diode 1N4002 | 1 | |
| Switch SPST | 1 | |
| 12V incandescent lamp | 1 | |
| Battery 12V | 1 |
When circuit turns ON capacitor C1 start charging through resistor R2 and then voltage on C1 goes up and then turns ON the transistor Q1.
After that, Q1 ON and C1 discharge through resistor R1 and this pull down gate of transistor Q2 and then Q2 turns ON and act like switch, lamp L1 lights up.
Then C1 keep discharging and gate voltage of Q2 goes down and Q2 turns OFF and also lamp goes OFF and process repeat.
Now, the flash speed depends on how fast C1 charges and discharges, then R2 and C1 control this rate and then the circuit can draw power directly from the car battery.
Formulas with calculations:
Formula and calculation for simple 12V lamp flasher:
Time for capacitor to charge:
T = R × C
R = 220k, C = 10μF = 0.00001F
T = 220,000 × 0.00001 = 2.2 sec (approx)
Full flash cycle time:
T = 0.693 × R × C
T = 0.693 × 220,000 × 0.00001 = 15.246 sec (approx)
Flash speed (frequency):
f = 1 ÷ T
f = 1 ÷ 15.246 = 0.066 Hz
So the flash speed is around 4 flashes per minute.
How to Build:
To build a Simple 12V Single Lamp Flasher Circuit follow the below steps:
- First, gather all parts shown in diagram.
- Next, connect Q1 collector to one side of R1 and other side of R1 to GND, connect Q1 base to negative of C2 and positive of C2 to one side of R3 and other side of R3 to Q2 drain and then connect Q1 emitter to +12V.
- Then connect C1 positive to point between Q1 emitter and D1 and negative of C1 to GND.
- After that, connect one end of R2 between Q1 base and C2 negative and other end of R2 to GND.
- Also, connect Q2 gate to point between Q1 collector and R1, connect Q2 drain to one side of R3 and then connect Q2 source to GND.
- Finally, connect lamp L1 and switch S1 between +12V battery and GND.
Conclusion:
Overall, this Simple 12V Single Lamp Flasher Circuit is easy, cheap and useful, as it shows how transistor and MOSFET make flashing.
Also, change resistor and capacitor to adjust flash speed and this circuit is good for car lights, alarms, fun lights and is great to learn timing circuit.