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The Graetz Bridge (Full-Wave Rectifier)

·116 words·1 min·
Stefano
Author
Stefano

The Graetz Bridge
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A full-wave bridge rectifier using 4 diodes to convert AC to DC. The most common rectification method.

Graetz bridge animation
Graetz bridge operation - Public domain

How It Works
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  • Positive half-cycle: D1 and D3 conduct
  • Negative half-cycle: D2 and D4 conduct
  • Current through the load always flows in the same direction

Output voltage: \(V_{out} \approx |V_{in}| - 2V_D\) (voltage drop across 2 diodes ≈ 1.4V)

With Capacitor Filter
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A capacitor in parallel smooths the output. Larger capacitor → smaller ripple → more stable DC.

DC average voltage (without filter): \(V_{DC} = \frac{2 V_{max}}{\pi} - 2V_D\)

Applications
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Power supplies, chargers, AC/DC converters — present in nearly every device plugged into a wall socket.