A590 PSU

A590 PSU schematic

The A590 is a bit of a confusing power supply , as it looks just like an AMIGA power supply but without a power switch . It also has a round Din type plug on the lead , instead of the square AMIGA style connection .

As a lot of people have been asking about the PSU for the A590 i thought i would take mine apart and reverse engineer a schematic diagram of it.

First the PCB wiring.

On mine the AMIGA connector colors are as follows.

Brown = +5v

White = GND

Red = +12v

Black = 5V sense

Green = Screen ( Directly connected to the earth input )

I have broken the schematic into three parts:-

1. mains control and DC rectification
2. 12V Supply
3. 5V Supply

Part 1 Mains control and DC rectification .
This contains the bit that most people ask about ‘ what is the 5v sense for? ‘.

Here is a schematic for this section .

Answer : – The 5v sense line ( actually the 5v supply from the AMIGA sidecar connector ) operates the relay to turn the power supply on .

The output of the transformer is 18.3v a.c. under load.

Here is a picture of the relay and associated components.

Part 2 12V supply.

The 12v supply is quite a basic circuit.

Here is the schematic for it.

Part 3 5V supply

The 5V circuit is a bit more complex , using a PWM control I.C. to create a switch mode supply.

Here is the schematic for it.

I have tried to include all values , where possible.

Unfortunately I cannot do this for the transformer or the L1 inductor.

If you find any discrepencies , please contact me with details so that i can rectify them!

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