simple regulated power supply

30 simple regulated power supply If you compare the expense and the rating of this power supply you will get a surprise, because the output voltage and current are fully ad- justable between 0 ... 18 V and 0 ... 1.8 A respectively and costs smoothing capacitor (C2). Diode D5 and capacitor Cl produce a negative auxiliary voltage, which is stabilized by zener diode D6 and capacitor C4. The negative voltage provides the negative supply for the two ICs. All this is necessary to enable the output voltage to be adjusted down to zero volts. During the construc- tion of this part of the circuit bear in mind that the positive lead of elec- trolytic capacitor C4 is connected to earth! divider made up of R5 and P2 (this pot sets the value of the output voltage). IC2 is connected as a differential amplifier and compares the signals at its two inputs. The difference between the inputs is the voltage drop across "current" sensor R4. This IC feeds the current sensing input (pin 2) of the L200. P...