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Welcome to this instructable where I will show you how I made this 12volts to 220volts DC-DC converter with feedback to stabilize output voltage and low battery/ under-voltage protection, without using any microcontroller. Even though the output is high voltage DC(and not AC) we can run LED Lamps, Phone Chargers and other SMPS based devices from this unit. This converter cannot run any inductive or transformer based load like AC motor or fan.

For this project I will be using the popular SG3525 PWM control IC to step up the DC voltage and provide necessary feedback to control the output voltage. This project uses very simple components and some of them are salvaged from old computer power supplies. Lets get building!

Supplies:
EI-33 ferrite transformer with bobbin (you can buy this from your local electronics store or salvage it from a computer PSU)
IRF3205 MOSFETs - 2
7809 voltage regulator -1
SG3525 PWM controller IC
OP07/ IC741/ or any other Operational Amplifier IC
Capacitor: 0.1uF(104)- 3
Capacitor: 0.001uF(102)- 1
Capacitor: 3.3uF 400V non-polar ceramic capacitor
Capacitor: 3.3uF 400V polar electrolytic capacitor( you can use a higher value of capacitance)
Capacitor: 47uF electrolytic
Capacitor: 470uF electrolytic
Resistor: 10K resistors-7
Resistor: 470K
Resistor: 560K
Resistor: 22 Ohms - 2
Variable Resistor/ Preset: 10K -2 , 50K - 1
UF4007 fast recovery diodes - 4
16 pin IC socket
8 pin IC socket
Screw terminals: 2
Heatsink for mounting MOSFET and voltage regulator(from old computer PSU)
Perfboard or Veroboard
Connecting wires
Soldering kit”

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