Powerful power unit 13,6 V, 20 A

In radio amateur practice quite often there is a need for the powerful power supply with target tension of an automobile onboard network. On fig. 1 the schematic diagram of such power unit is provided.

the Secondary winding of the transformer should be calculated by font on a current 20 And and 20 V.Diody's tension of the bridge are established on radiators, it is better to use power diodes with Shottka's barrier. Diodes should be not lower on working tension 50 volts and a working current not less than 20 amperes. The stabilizer with protection against short circuits is executed on VT1 transistors... VT7. Target tension is established by the tuning resistor 1ком. The amplifier of a signal of a mistake is executed on the differential cascade VT6, VT7. The repeater on the compound VT5 transistor operates regulating VT1 transistors... VT4 in which emitterny chains the leveling resistors of 0,12 Ohm providing uniform distribution of a current on all four transistors (on 5 And on everyone are switched on). the Printed-circuit board of the device is shown to p by

on fig. 2. The network rectifier, filtering condensers and VT1 transistors... VT4 are established out of a payment. VT1 collectors. . VT4 are galvanic connected to the case that allows to use the chassis as a radiator without isolating laying.

as VT1... VT4 can use КТ819, VT5 - КТ827, VT6 and VT7-KT814. In total - with any letter.

Radio fan, N9 1993 g