Variable PSU

August 29, 2010 - category: Power supplies


A variable power supply with adjustable voltage and current outputs made with the L200 regulator.

Variable PSU circuit diagram


Using the versatile L200 voltage regulator, this power supply has independent voltage and current limits. The mains transformer has a 12volt, 2 amp rated secondary, the primary winding should equal the electricity supply in your country, which is 240V here in the UK. The 10k control is adjusts voltage output from about 3 to 15 volts, and the 47 ohm control is the current limit. This is 10mA minimum and 2 amp maximum. Reaching the current limit will reduce the output voltage to zero. Voltage and current regulation equations can be found at this page.

Author and source

author: Andy Collinson

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