Boost Converter Circuit 555

Boost Converter Circuit 555 is designed based on timer IC 555 and few easy to avail external components. This circuit is designed to provide 9 Volt output from 3 volt input power supply. If you need high voltage from 3 volt battery you can use this circuit to boost supply voltage.

In this boost converter circuit Timer IC 555 configured in Astable multivibrator mode and we can adjust the output voltage by varying the output pulse frequency of timer IC.

Circuit Diagram

Components Required

  1. Timer IC 555
  2. Transistor BC547 NPN
  3. Diode 1N4007
  4. Variable Resistor 20KΩ
  5. Resistor 1KΩ, 330Ω each one
  6. Capacitor 470pF, 0.01µF, 0.1µF each one
  7. Inductor 80µH

Construction & Working

Timer IC 555 is configured in Astable multivibrator mode to produce Continuous pulse output, by the value of RV1 variable resistor we can increase or decrease the output pulse frequency.

Here RA = R1, RB = RV1 and C = C1.

Output pulse from the timer IC is applied to the transistor base (Q1), here transistor Q1 acts as a switch, Collector terminal of Q1 is connected to the positive power supply through Inductor L1 and emitter terminal is connected to the negative supply. Boosted output voltage is taken from the L1 and Q1 meet point and then Rectified by the diode D1. C3 capacitor removes ripples and noise from the output voltage.

Timer IC 555 Pin Configuration

Here we used Dual in line package 8 Pin 555 IC. Operating voltage range of this IC range from 3V to 12V.

Transistor BC547 Pin diagram

BC547 is a Three terminal two junction NPN transistor, BC547 is most suitable for general purpose amplification, switching applications.


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