Replacement PSU for ZX Spectrum 48K

[mores...@gmail.com]

Hi,

I have recently acquired a ZX Spectrum 48K without a power supply. I found out the original psu specs to be "9v dc, 1.4a, -ve, unregulated, 5.5mmx2.1mm". This is very hard to find in US (ebay, my local RadioShack), especially for "-ve". I tried with lower max amp (I heard about 850ma is enough for speccy alone), but still have trouble matching the "-ve" requirement.

Anyone knows where to find a good replacement psu in US? A link would be very appreciated.

Thanks,
Mark

[Brian Gaff]

Well don't know about the US, but there used to be some supplies made with
enough current and configurable to the right polarity and plug type. I used
to see them branded as Radio Shack, but as these folk no longer sell in the
UK, I'm a bit out of touch.
Mind you they were bigger and heavier than the old Spectrum ones were, maybe
now they are all switch mode.


Brian

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<mores...@gmail.com> wrote in message
news:09098404-c5e7-47c8...@googlegroups.com...

[Volker Bartheld]

Hi Mark!

On Sat, 5 Jan 2013 21:05:46 -0800 (PST), mores...@gmail.com wrote:
> I have recently acquired a ZX Spectrum 48K without a power supply. I
> found out the original psu specs to be "9v dc, 1.4a, -ve, unregulated,
> 5.5mmx2.1mm". This is very hard to find in US (ebay, my local
> RadioShack), especially for "-ve". I tried with lower max amp (I heard
> about 850ma is enough for speccy alone), but still have trouble matching
> the "-ve" requirement. Anyone knows where to find a good replacement psu
> in US?

Almost any 9V unit will do that delivers around 1.5-2 amps. I'd be careful
with cheap switching supplies (especially if they are not properly
shielded using capacitors etc.), as they could create some nasty spikes
and surges your Speccy might not be prepared to digest.

If the connector doesn't match: This is biggie at all. You can cut the
cable and solder on a power supply plug similar to this one here [1]. I
guess the Id 2.1, Od 5.5 mm version is correct (also works with the
Arduino Uno), but you might want to take out your caliper and check.

Good luck!

Volker

P.S.: I'm using [2] for my Speccy-experiments which works fine. It's a
little small for extended work but OK for typing a few commands to
activate the RS232-connection or run Microdrives. Make sure to apply the
"ZX Spectrum Composite Video Mod" which will save you from a lot of hassle
with the RF modulator.

[1] https://www.buerklin.com/default.asp?event=ShowSE()&search=40+F+102
[2] http://amazon.de/Zoll-Mini-Monitor-NTSC-R�ckfahrkamera/dp/B004VQD966
[3] http://womblesretrorepairshack.blogspot.com/2008/11/zx-spectrum-composite-video-mod.html

--
@: I N F O at B A R T H E L D dot N E T
3W: www.bartheld.net

[Brian Gaff]

Well if it willrun microdrives its not that bad. I was going to suggest a
bit of a bodge I used to do when not finding the right supply, simply buy
two and put the outputs in paralell. It might soundt a bit odd but no harm
ever came to anyting as long as they were the same types.

Brian

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Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email: bri...@blueyonder.co.uk
______________________________________________________________________________________________________________


"Volker Bartheld" <dr_ve...@freenet.de> wrote in message
news:2kisx4p3a6y9$.dlg@news.bartheld.net...

[Chris Cowley]

One of these wound do the trick, wouldn't it?

http://www.amazon.com/Velleman-Compact-Universal-Adapter-Supply/dp/B0006
8U44I/ref=sr_1_1?ie=UTF8&qid=1357512271&sr=8-1&keywords=universal+dc+pow
er+adapter

--
Chris Cowley

[mores...@gmail.com]

Thanks for every one info.

I have come across this webpage that talk about running zx spectrum in Japan.

http://pcbiroiro.blogspot.com/2012/01/running-zx-spectrum-in-japan.html

He used a sega megadrive psu which has 9v dc, 1.2a -ve. He said a speccy without any add-ons (my intended configuration) would draw about 800ma, so 1.2a-max psu should be sufficient.

This is the one I am going to buy from ebay. What do you think?

http://www.ebay.com/itm/Genuine-Sega-Genesis-AC-Power-Adapter-Model-1602-9V-/200870511554?pt=Video_Games_Accessories&hash=item2ec4d0c3c2&_trksid=bvizzzzzzOkz

Thanks,
Mark

[mores...@gmail.com]

One of these wound do the trick, wouldn't it?

http://www.amazon.com/Velleman-Compact-Universal-Adapter-Supply/dp/B0006
8U44I/ref=sr_1_1?ie=UTF8&qid=1357512271&sr=8-1&keywords=universal+dc+pow
er+adapter

This one looks very promising. At first, I was not sure about its polarity. After reading reviews, I found that it has configurable polarity (+/- ve). I am considering buy this one instead of the sega psu mentioned previously.

Mark

[hp]

On 1/6/2013 1:24 PM, Brian Gaff wrote:
> Well if it will run microdrives its not that bad. I was going to

> suggest a bit of a bodge I used to do when not finding the right

> supply, simply buy two and put the outputs in parallel. It might
> sound a bit odd but no harm ever came to anything as long as they

> were the same types.

> Brian

Since we used to deal in Spectrum/Timex when it came time to hardwire up
a nice enclosure for the TS1000 project, full sized keyboard, 64K ram,
and a few other little tricks that made it very usable, the simple way
to ensure the power was adequate for the whole thing that is exactly
what I did. We weren't lacking in power supplies back then.
Mounted 2 female mini power supply jacks to the case, plug in 2 brick
power supplies plenty of power for the TS1000, the extra ram and the
other assorted extras I wired into the thing.
Neither was stressed enough to heat up much at all.

Think I still have that setup stuffed away somewhere.

Used a few extra keys to hard-wire a 'reset' 2 key press combination too.