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