Power unit 0... 12 volts

the Power unit work with div from 12 V.Vypryamitel's alternating voltage is collected on D1-D4 diodes. The greatest current given by the power unit to loading (to 300 mA) is limited by an admissible direct current of diodes of the rectifier.

In the rectifier can use any powerful diodes (not to forget about the most admissible current of a secondary winding of the transformer). The variable R2 resistor - with the food switch, it is desirable with a linear scale (group A). Instead of the MP39 transistor it is possible to use MP40-MP42 transistors, and instead of P213-tranzistory П214, П215. The factor of strengthening of transistors should be not less than 15. It is possible to replace stabilitron Д813 with stabilitrons Д811, Д814Г, or Д814Д. The greatest tension on an exit of the block will correspond to tension of stabilization of a stabilitron used in the block.