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Sunday, October 18, 2009

Symmetric Power Supply without CT Transformer

This is a kind design of power supply. It is like a center tapped transformer with a bridge diode is common solution to provide symmetric supply, but we can actually do it with simple solution, using a voltage double - rectifier diodes. This is the figure of the circuit.

The capacitor need to be large because the rectifying is half wave, so you can avoid power line hum. With the component values shown, the power supply is capable supplying 10mA at ripple voltage about 0.2V (peak to peak). The voltage ripple can be approximated by Vripple = (20 x I)/C, where I is the current drawn by the load in mA, and C is the capacitance in uF (micro farad).


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  2. Nice blog.

    I got so much information about micro power supply .thanks for sharing this .