Variable Voltage Regulator based LM117

The regulator circuit uses an LM117K three-terminal adjustable output positive voltage regulator in a TO-3 can. The variable voltage regulator lets you adjust the output voltage of a fixed DC power supply between 1.2 and 37 VDC, and will supply the output current in excess of 1.5 A.

Thermal overload protection and short-circuit current-limiting constant with temperature are included in the package. Capacitor Cl reduces sensitivity to input line impedance, and C2 reduces excessive ringing. Diode CR1 prevents C2 from diseharoinu through the IC during an output short.