Amiga ATX power adaptors

Introduction

I now produce a range of adapters that  allows you to use an ATX power supply with an Amiga.
It does require you to use your existing power lead. Full instructions are provided.
Please refer to the Amiga power supply guide for additional information

Original/Bog box adaptor


Suitable for installation into an ATX tower case or inside an A1000, A1500, A2000, A3000(Big Box) Amiga,
 this adapter provides the -5V and ‘Tick’ signal. For the A3000, the FAIL signal is available to use.
This is the highest rated power adapter available, it can safely handle the following power levels:
+5V @ 15A
+12V @ 8A
This yields a system power of 175W.
One DIP switch sets the power switch type, momentary (as used on ATX cases) or latching (as used on original power cases.  The other DIP switch sets the ‘Tick’ frequency.
PCB dimensions, 68x41mm


picoPSU Adaptor

Designed for installation inside the Amiga, especially suitable for the A500/A600/A1200. The right angled
connector provides a lower profile. You can operate the unit using a toggle or push to make switch.

I use a 90W picoPSU power supply, with a 60W mains adaptor, this has been sufficient to operate my A600 and A1200/040 with CD-ROM.
PCB dimensions, 51x51mm

CDTV power adapter

Now available, this has been designed to allow you to replace the existing power supply inside the CDTV.
You can use a regular or picoPSU ATX power supply.

Selecting the correct model for your system

To make it easier to select the correct model, use the table below.

Model(s)Recommended adapterNotes
A500, A600, CD32pisoPSUSuggest fitting picoPSU + adaptor PCB in the original case with mains adaptor external
A1200pisoPSU/Big boxFor desktop systems I recommend the pisoPSU. For higher spec systems consider the big-box system.
A1500, A2000, A3000, A3000T, A4000, A4000TBig-box adaptorYou may need to solder a wire to the FAIL PCB pad depending on the model. Use normal or 90W+ picoPSU.
CDTVCDTVSee fitting guide below.

Important note on DIP switch settings for current models

The 2016 edition adaptor PCBs use a microcontroller to control the power supply and provide the ‘Tick’ signal. It is important that the DIP switches are correctly set before connecting the ATX PSU. The microcontroller is powered from the +5VSB (standby) supply and sample two discrete inputs on powerup, they determine the switch type (momentary or latching) and tick frequency (50 or 60 Hz). If you set the switches incorrectly, simply unplug the ATX power supply and set them as desired, then re-connect the power supply. There is no EEPROM in the microcontroller, it always determines the configuration on power up.


The photo above should make it clear. on the picoPSU adaptor, you only need to set the top DIP switch as the ‘Tick’ signal is not required. It is recommended to set both switches to the same setting on the picoPSU, to avoid confusion.
If you have the wrong setting, you will know, either it powers off immediately when you release the switch if latching mode selected and using an ATX momentary switch, or if momentary mode is selected the system will not switch off until the power switch is activated a second time.


Using ATX adapters without a power switch
It is easy to use the power adapter without a power switch, especially if you are re-building an Amiga ‘brick’ supply.
Simply set the DIP switch to Latching mode and short out the two power switch jumpers, either by using a 0.1″ jumper or by soldering a piece of wire in the adjacent two holes in the PCB, shown here in red.

 The power supply assembly will then turn on/off with the AC mains input.

You can mount the adaptor inside the Amiga casing. This is popular with Amiga A600 users as shown here:
 Mario Filos’ A600 has one of my prototype adaptors, it was on his suggestion that this variant was created.
Photo of the installed unit here: img84.imageshack.us/img84/1895/dsc03099r.jpg
An updated picture is here, if you can spot the adaptor board 🙂 mfilos.blogspot.co.uk/2011/01/one-more-morning-update-coming-ahead.html
 Impressive work!

Externally cased power supply
Taken from the A1k.org website:
www.a1k.org/forum/showthread.php?t=36199


Installation suggestions

3D CAD models for the ATX adapters 

3D Printed custom case
Thanks to Leigh Russ, you can print your own case via Thingiverse,1794271



With a recent ECAD upgrade it has become much easier to generate 3D models of the adapters.
The Big-box ATX adaptor STL file is here(2.60Mb)
The PicoPSU adaptor STL file is here (847KB)



CDTV Installation information.

Thanks to Björn Lange, I can now provide details on how to replace the CDTV power supply with the smaller ATX adapter.

Original CDTV power supply with top cover removed


Closeup of original CDTV power connectors that you must un plug and later connect to the adapter

Adaptor connected up ready for installation inside the CDTV

Another photo of the adaptor ready for installation

Installed adaptor inside the CDTV

Common design features

No modifications required to the ATX PSU.
Only 4 wires to install .
Works with either latching (clickable) or momentary push button switches..
Capable of powering a fully expanded PPC Amiga.
.
Pricing and ordering

Please go to the Sales page


If you are resident in the UK and would like to pay by cheque, please contact me,  and I will supply my address for you to send the
cheque to

Support (updated manuals available soon)

Installation manual (605K PDF file).
The schematics and PCB layout are available here (87 K zip file).

picoPSU Adaptor installation manual (199K PDF file)

The adaptors have been tested with a number of ATX power supplies, all worked without issue. The only clarification I would make is relating to the on/off timing.

 

Design files
You can download the schematics and PCB layout forall of the designs on github
https://github.com/istedman/ATX_adaptors



PCB power rating
The tracking of the PCBs can safely conduct the following currents:
Original/Multi-ATX/picoPSU
+5V @ 5A
+12V @ 2.5A
-12V @ 1.8A
Original/Big Box
+5V @ 15A
+12V @ 8A
-5V @ 0.4A

By Ian Stedman,   14 April 2021.