Friday, March 8, 2013

40A Stabilized Power Supply Circuit

40A Stabilized Power Supply CircuitThis power supply is designed for amateurs, and has been in operation for over 10 years. Its design is simple and virtually immune to RF. It brings together the individual pieces, is the most expensive of 600 VA toroidal transformer, which can be replaced by another with different characteristics in the case of a voltage between 17 ~ 20V power and adequate for our needs.

Reference voltage of 7.5 V Zenner diode (6V8 8V2 ~), shall apply to Q2, which compares the input voltage divider consisting of resistor R5, R6 and VR2, address Darlington amplifier Q3, which is responsible for driving the output stage, which consists of a driver in Q4 2N3771 NPN transistor and 4 power, which can be mounted directly on the heat sink without insulation, since it is a grounded collector.

The source has a current limit (Q1), adjusted by VR1 and overload LED (DL2) and full short circuit protection, with zero consumption in case of short circuit can be maintained indefinitely in this state without danger.

(Please note that due to the great power of the power supply with a casual a short length of cable, high or small section that is strong enough to not exceed the maximum current of 40A. There can be regarded as a short circuit and cause the supply of a large amount of power supply energy).

active rectifier (D1, D2) is recommended for a screw type metal cathode on the floor, installing a heat sink large enough blocks. As the power transistors with such a high as possible hedgehog, without being isolated as above, may be part of the window of an aluminum frame. We also recommend the use of mechanical ventilation with the thermostat.