“The circuit presented here is a very simple and easy to build Lab Power Supply. The output of this power supply is adjustable from 0 to 10V DC, and it has current limit control up to 3A. Two Trimmer potentiometers are provided to adjust the voltage and current. The input supply is DC 12V to 18V 3A or AC12V /3A. The screw terminals help to connect the input and output connections, and a large area on PCB provided as heat spread so no external heatsinks required. The power supply also includes over-temperature protection. The board is built using 2 x LT3083 chips, U1 is used as current source and U2 provides adjustable output voltage.
The LT®3083 is a 3A low dropout linear regulator that can be paralleled to increase output current or spread heat on surface mounted boards. Architected as a precision current source and voltage follower, this new regulator finds use in many applications requiring high current, adjustability to zero, and no heat sink. The device also brings out the collector of the pass transistor to allow low dropout operation— down to 310mV—when used with multiple supplies. A key feature of the LT3083 is the capability to supply a wide output voltage range. By using a reference current through a single resistor, the output voltage is programmed to any level between zero and 23V (DD-PAK and TO-220 packages). The LT3083 is stable with 10μF of capacitance on the output, and the IC is stable with small ceramic capacitors that do not require additional ESR as is common with other regulators. Internal protection circuitry includes current limiting and thermal limiting.”