This inverter circuit converts 12V DC to 220V AC (square wave) using a transformer and a few common components. It’s designed to handle up to 40 watts, suitable for light AC loads like LED bulbs, small fans, chargers, etc.
🔧 Basic Components Required:
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Transformer: 12V-0-12V to 220V (5A, center-tapped)
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Transistors: 2× TIP41 (or 2N3055/MJE13007)
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Resistors: 2× 220Ω (1W)
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Capacitor: 0.1µF ceramic
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Oscillator: Simple astable multivibrator (2× resistors + 2× capacitors OR IC-based)
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Battery: 12V lead-acid (7Ah or higher recommended)
⚙️ Working Principle:
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An oscillator circuit (transistor or IC 555-based) generates a square wave signal (~50Hz).
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This signal drives the base of two power transistors alternately.
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The transistors switch the center-tapped transformer, which steps up the 12V pulses to ~220V AC (square wave).
🔄 Circuit Schematic (Text Version):
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The bases of T1 and T2 are connected to an oscillator (either with transistors or 555 timer).
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The center tap of the transformer goes to +12V.
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The two ends of the 12V winding are connected to the collectors of the transistors.
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Emitters go to ground.
🛑 Important Notes:
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This produces a square wave, not a sine wave — not suitable for inductive loads (like motors or sensitive electronics).
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Ensure adequate heat sinks for the transistors.
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Use a fuse or protection circuit to prevent overload.
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For more efficiency and cleaner output, consider MOSFET-based or PWM-based inverter designs.
