Sinclair ZX Spectrum Power Supplies – What Types Are There (Part 5)? – The +3 (Disk Drive Spectrum)

There are several types of Sinclair ZX Spectrum. So it follows that there are several different types of power supplies for the Sinclair ZX Spectrum.

This ranges from the rubber key 16k and 48k models, then Plus and 128 models during the Sinclair ownership of the Spectrum brand, through the Amstrad ownership of the Spectrum brand (after Alan Sugar’s Amstrad bought the rights to the Sinclair Computer brand), to the present with the new Spectrum Next.

Part 1 of the PopeyMon articles on the types of Spectrum PSU talked about the rubber key models and the Spectrum Plus.

Part 2 dealt with just the Spectrum 128 (“Toastrack”).

The Amstrad-Owned Era of the Sinclair ZX Spectrum

Part 3 dealt with just the Grey +2.

Part 4 dealt with the Black +2 (+2A and +2B).

Part 5 deals with the +3, the disk version of the Spectrum.

Like the Grey +2 and the Black +2 – although the case is similar to the Amstrad CPC, the power still comes from an external power supply. On the original design of the CPC, there was only one plug, for the monitor and computer. The power for the computer came from a lead that went from the monitor to the CPC. There was only one plug.

The +3 has one plug for the computer unit, but you still need a plug for your separate display.

The Black +3 PSU could be referred to as a “power brick”, like the Xbox 360 PSU. It is very heavy. It generates the voltages on different lines to a DIN connector, instead of the barrel connector used for the UK1400.

The +3 PSU is much larger than the earlier Spectrum PSUs. The voltages and current rating are shown in the photos above, and described below.

It generates:

• +5V at 2A
• +12V at 700mA
• -12V at 50mA

These are connected to the pins on the DIN connector. Different voltages are needed for different functions of the +3.

The ratings are VERY SIMILAR, but NOT IDENTIAL to the +2 PSU. The +3 needs more current, so the +3 power supply can be used on a Black +2. BUT NOT THE OTHER WAY AROUND. The Black +2 PSU should NOT be used on a +3.

This article will be updated with some photos of the internals, in the near future.

If you are looking to buy any Sinclair power supply or want one checked, please get in touch. I will happily sell you one – fully tested and working – for the Spectrum 16/48k/Plus, for the grey +2 or the black +2 or +3. I also have a lot of other Spectrum parts, working computers and games for sale. I will happily put together a custom bundle for you.

I will be writing more about the Spectrum power supplies in the near future. This series will conclude with the Amstrad-era models of the Spectrum, the Black +2 (Part 4) and the +3 (Part 5). When I finally get my Spectrum Next (that I’ve already paid for via the Kickstarter 2), I might even do an article on that, too! Watch this space!