IC 555 Timer Based Mini Flasher Circuit makes LED blink light with a set speed.
This circuit often uses for signal, indicator and hobby projects.
IC 555 timer work in astable mode to give pulses all the time.
We can change blink speed with a potentiometer.
The circuit power it with 6V battery or 6V DC supply.
Circuit Working:
Parts List:
| Component | Value/Specification | Quantity |
|---|---|---|
| Resistors (All resistors are 1/4 watt unless specified) | ||
| 1k | 2 | |
| 4.7k | 1 | |
| Potentiometer 100k | 1 | |
| Capacitors | ||
| Ceramic 0.01µF | 1 | |
| Electrolytic 10µF 25V | 1 | |
| Semiconductors | ||
| IC 555 Timer | 1 | |
| LED 5mm 20mA | 1 | |
| Battery 6V | 1 |
This circuit uses special chip called IC 555 timer.
It make steady pulses.
Pulse speed change by resistors R1, R2, VR1 and capacitor C2.
When power is ON the capacitor C2 charges and discharge to make pulses.
Capacitor C1 keep control voltage steady for smooth pulses.
Resistor R3 stop LED and get too much power so there is no burn.
Output from pin 3 goes high and goes low to turn LED ON and OFF.
Formulas with Calculations:
IC 555 mini flasher formulas here:
Frequency (f) = 1.44 / ((R1 + 2×VR1) × C2)
ON time (T_high) = 0.693 × (R1 + VR1) × C2
OFF time (T_low) = 0.693 × VR1 × C2
where,
- R1 is 1kΩ = 1000Ω
- VR1 is 100kΩ
- C2 is 10µF = 10 × 10⁻⁶ F
Calculate frequency:
f = 1.44 / ((1000 + 2×100000) × 10×10⁻⁶)
f = 0.716 Hz
Calculate ON time:
T_high = 0.7 seconds
Calculate OFF time:
T_low = 0.693 seconds
Total time (T) = T_high + T_low = 1.393 seconds
Check frequency:
f = 1 / T = 0.717 Hz
So with VR1 at 100k the LED blinks to about 0.717 times per second.
Full blink ON/OFF cycle take 1.39 sec.
Turn VR1 to change blink speed faster or slower.
How to Build:
To build a IC 555 Timer Based Mini Flasher Circuit follow the below mentioned circuit connections steps:
- Get all parts as per circuit diagram
- Pin 1 of IC1 555 goes to GND.
- Pin 2 connect to pin 6 on IC1.
- Pin 3 connect to LED1 anode and LED1 cathode go to one side of R3 and other side of R3 goes to GND.
- Pin 4 and pin 8 connect to positive supply.
- Pin 5 connect to GND through capacitor C1.
- Put pot VR1 and resistor R1 between pin 7 and pin 6.
- Positive of capacitor C2 go to pin 6 and negative of C2 go to GND.
- Resistor R2 go between pin 7 and positive supply.
- Connect +6V battery positive to circuit positive and negative battery to GND.
Conclusion:
This IC 555 Timer Based Mini Flasher Circuit is simple and good to blink LED.
It uses IC 555 in astable mode to make LED flash.
It change resistor and capacitor to adjust flash speed.
Circuit is Good for beginners, small projects and indicators