Improvement of power supply

Commercially available power supplies, Chinese manufacture at several voltages when connected to the player or the receiver give a background of alternating current, as in the filter after the diode bridge is only electrolytic capacitor 470 μf.

Offer a simple revision of the unit, significantly reducing the level of pulsation. Additional details are placed in the body of the unit itself.

Diagram of the improved block specific explanations are not required. The transistor is preferably set to a small radiator from a piece of tin.

The switch voltages SB1 after processing scheme gives a "shifted" to 1.5 a levels. If desired, you can resolder the wires that are appropriate for SB1, and to restore the correspondence between specified on the switch and the output voltage, but then the upper limit (12 In) will not.

Author: O. Klevtsov, Dnipropetrovsk; Publication: N. Bolshakov, rf.atnn.ru