Replacing ZX81 power input

Discussions about Sinclair ZX80 and ZX81 Hardware
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Shaun_B
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Joined: Wed Apr 22, 2009 10:22 am

Replacing ZX81 power input

Post by Shaun_B »

Is it possible & relatively easy to change the power input on the ZX81 to use a Spectrum PSU?

Thanks,

Shaun
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Paul
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Re: Replacing ZX81 power input

Post by Paul »

The ZX81 pcb isn't ready to take a different input.
So an adapter cable is the best way to get a spectrum psu to work with the ZX81.
Be aware the spectrum plug is quite common and in 99% it's polarity is inverted. So there is possible danger of destroying your ZX81.
A simple diode that is capable of 2A load should prevent this. Or a full rectifier. Then you can use spectrum and other 7-14V power sources without any harm for your Zeddy.
Kind regards Paul
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Shaun_B
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Re: Replacing ZX81 power input

Post by Shaun_B »

Thanks Paul.

Is there a suitable replacement for a ZX81 power supply that I may purchase?

Regards,

Shaun
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Paul
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Re: Replacing ZX81 power input

Post by Paul »

There are plenty.
E. G. https://www.amazon.de/gp/aw/d/B002TQ220 ... th=1&psc=1
Put it on 7,5V and plug in the 3.5mm Jack (TIP Is plus)
Kind regards Paul
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1024MAK
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Re: Replacing ZX81 power input

Post by 1024MAK »

I give advice on replacement power supply units here.

Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp

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ts_mike
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Re: Replacing ZX81 power input

Post by ts_mike »

A power supply from an old Atari 2600 VCS game console has always worked well for my TS1000 (the US version of the ZX81). Careful if you buy a 3rd party supply. You'll want to have at least 700 mAmps and not all of the 3rd party ones supply that amount.
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