variable 2 V … 60 V power supply

7-50 — eiektor july/august 1981 is Or variable 2V. . 60V power supP1Y The L146 type integratedcircuit from SGS-Ates is pin compatible with and an improved version of the well known 723 regulator IC. The major difference between this new IC and the older type is definitely an advantage. The maximum supply voltage that the 723 will handle is 40 V, while the maximum input voltage to the L146 is 80 V. With the aid of an external transistor or two it is ib i■ possible to construct a variable power supply with an output voltage that can be regulated between 2 V and 60 V. In the circuit shown, potentiometer P1 is used to set the current limit to anything between 10 mA and 1 A. Some readers may ques- tion the validity of specifying a current output of 10 mA for a power supply. Let us then emphasise output voltage of 60 V w (high voltage end). MJ 3001 R4 the fact that this figure refers to the current 01 . D4 = 1N4003 Tr1 n 4 ,1V limit Parts list Resistors: R1 = 22 k R2 = 6k8 R3 = 2k2 ...