This is the circuit diagram of dual output power supply +/-53V / 3A based on transistors. This circuit has been designed for audio amplifier power supply requires a symmetrical + / -53 V (+ / -56 V maximum). The role of the circuit part presented here is to lower the voltage of both positive and negative lines of + / -65 V for non-hazardous + / -53 V for the amplifier, while allowing the current to 3 A in continuous operation.
The diagram above, based on the same principle as the previous circuit Dual supply + /-15V-based transistors, and is based on the use of common components. Differences of Dual supply + /-15V-based transistors, lies only in the number of transistors connected in cascade to allow high output currents while not requiring a zener diode of 10 W for output voltage stabilization. The main advantage of this type of configuration is to have a high current gain. The second point is not important in this case. Power dissipation in the ‘final’ two transistor Q3, and Q6 to 3 A output current, is about 36 W, which require a large heatsink. Transistors Q2 and Q5 is recommended fitted fin heat sink (for TO5 case).
Caution : The controller is not protected against short circuit, because it’s important to use with fuses (one for each input line). You really need to realize that if a short-circuit transistors Q3 and Q6, the input voltage is slowly following the path of the output and then to the power amplifier. Ideally is to place the overvoltage detection circuit at the output controller, which can be started like thyristors connected in parallel to the second input channel.
