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    1. From squinting at the image:

      A benchtop power supply is a must-have for anyone working with electronics. They supply stable voltages with fine-grained adjustment, and they often feature controllable current limits with the ability to connect power easily ainto circuits witih chips, probes or plain old wire.

      Sadky, they aren’t cheap; even a basic single-output model starts at around 40(?) and if you want multiple simultaneous outputs and more esoteric voltages, such as the negative voltages required by audio equipment and some vintage computer hardware – you can pay much more.

      If there was only a choice we hll had lying around that could do the same job. A device such as, I don’t know, an ATX power supply unit. But how would you ever connect the cables to that PSU safely? The answer is to use Dangerous Prototypes’ open hardware ATX breakout board kindly provided by the guys at Phenoptix, this ATX board has now become an essential part of my toolkit.

      It’s operation is simple – connect any ATX PSU to the header at the top and you can then break out the voltages to its screw terminals which are capable of accepting banana plugs. For most PSUs that means immediate access to ??V 5V, 3.3V and the ever-so-handy 12V rails. There’s also room for an additional terminal – not supplied – if you have an older PSU with the long-since-removed ?V line.

      The board is built with safety in mind too. Unlike a standard benchtop power supply which typically tops out at around 5A of current, an ATX PSU is designed to pump serious power down its [mangled] rails – more than enough to melt wires and start fires if you have a short circuit. As a result, the board includes 1.25A polyfuses which automatically reset if tripped to limit the current you can draw from the PSU.

      That means you can’t use the board to power current-hungry devices – at least, not without modification – but that isn’t the board’s purpose. As a flexible benchtop power supply for testing bare circuits or devices missing their original PSUs the ATX Breakout Board shines.

      Each power rail also includes an individual LED, turning the board into a simple PSU tester as an added bonus. The design has room for a 5W(?) resistor too, for those rare PSUs that refuse to switch on if there’s no load present, but I didn’t need that feature for any of my spares. If your power supply does need it, and if you have one of the older PSUs with a handy-dandy-5V rail it’s a simple job to solder the supplied resistor in place on the board.

      While not as flexible as my real benchtop supply – which can be adjusted from 0-30V in 0.1V increments – the ATX Breakout Board is still just as acceptable for most jobs and it’s much cheaper too. Phenoptix sells the board for £12.59 inc VAT [url] with an optional, and highly recommended acrylic case costing an additional £5 inc VAT. With its ability to make use of any spare ATX PSU you have lying around, that’s a very cheap way to get a range of voltages onto your test bench quickly and safely.

      The device acts as a handy way to test power supplies themselves: hook up its terminals to a multimeter and you can quickly connect and disconnect PSUs for testing.

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