Pictures of my ZX81 fitted with a RECOM 5V Regulator

Discussions about Sinclair ZX80 and ZX81 Hardware
Lardo Boffin
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Re: Pictures of my ZX81 fitted with a RECOM 5V Regulator

Post by Lardo Boffin » Mon May 21, 2018 4:45 pm

Try this MuRata one - it is 1.5a

https://www.retroleum.co.uk/spectrum-128-modifications

I have bought a bunch of stuff off this site.

As I understand it the toastrack sucks up most of the output of the original regulator so if you run it with anything plugged in it is not good.
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1024MAK
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Re: Pictures of my ZX81 fitted with a RECOM 5V Regulator

Post by 1024MAK » Mon May 21, 2018 7:37 pm

1.5A and 2A types are available from the large electronic companies. For example, RS components in the U.K. have some (link to listings of Recom types).

Mark

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adonet
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Re: Pictures of my ZX81 fitted with a RECOM 5V Regulator

Post by adonet » Wed May 23, 2018 9:11 pm

I found this one for ZX Spectrum 128K for sale in Holland:
https://www.conrad.nl/p/tracopower-tsr- ... -x-1511338
traco2.jpg
traco2.jpg (19.75 KiB) Viewed 353 times
and this one for ZX Spectrum 48K and ZX Spectrum + 48K and ZX 81
https://www.conrad.nl/p/tracopower-tsr- ... 1-x-156673
and in UK
https://www.conrad-electronic.co.uk/ce/ ... archDetail
traco1.jpg
traco1.jpg (17.55 KiB) Viewed 353 times
I have been ZX computing since 1981, Zx81, 16Krampack, ZX Spectrum 48, Alphacom32, ZX Spectrum +, Lo>>profile keyboard, ZX Spectrum 128K
Ubuntu 18.04 and Raspberry PI

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gammaray
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Re: Pictures of my ZX81 fitted with a RECOM 5V Regulator

Post by gammaray » Fri May 25, 2018 10:26 pm

Mandatory equipment in my mind. Makes room for fan and minimizes power rejection causing heat. I used a uncased 'Chiner' model mounted at right angle.

https://www.sinclairzxworld.com/viewtop ... 036#p20770
Finish what you start. Truth is over the mountaintop or six feet under.
4 x TS1000, 2 x TS1500 , 2 x timex 2040 printer, 1/2 x timex 2020 cassette deck, ZXPAND+AY, ZeddyNET, ZXBlast..., unfinished Spectrum...Still no life!

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adonet
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Re: Pictures of my ZX81 fitted with a RECOM 5V Regulator

Post by adonet » Fri May 25, 2018 10:54 pm

Now it looks like this. The colour of the regulator is Both black instead of rose, but they are the same. 1amp for the zx81 and ZX. Spectrum. 2 amp for the zx spectrum 128k.

And they stay cool.
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I have been ZX computing since 1981, Zx81, 16Krampack, ZX Spectrum 48, Alphacom32, ZX Spectrum +, Lo>>profile keyboard, ZX Spectrum 128K
Ubuntu 18.04 and Raspberry PI

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gammaray
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Re: Pictures of my ZX81 fitted with a RECOM 5V Regulator

Post by gammaray » Fri May 25, 2018 11:10 pm

I just got a refurbed Spectrum from the Netherlands and intend to convert to NTSC with that version of the ULA and the right oscillators.

I'll need to change regulator as well. The heatsink seems to be 3 times the surface area as the TZX81000 heatsink but only twice the current.

Strange the ULA did not have provision for both markets like the ZX81 but I guess the change in oscillators prevented that.

Addendum:
I had bought a larger heatsink 30 years ago for ZX but I am not sure it lowered the overall case temperature given physics Andy's prior comments mention elsewhere. If anything it just delayed time it took to start reach
Last edited by gammaray on Sat May 26, 2018 2:28 am, edited 1 time in total.
Finish what you start. Truth is over the mountaintop or six feet under.
4 x TS1000, 2 x TS1500 , 2 x timex 2040 printer, 1/2 x timex 2020 cassette deck, ZXPAND+AY, ZeddyNET, ZXBlast..., unfinished Spectrum...Still no life!

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1024MAK
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Re: Pictures of my ZX81 fitted with a RECOM 5V Regulator

Post by 1024MAK » Sat May 26, 2018 1:37 am

Drifting way off topic here :shock:
The ZX Spectrum ULA picture circuitry is far more complex than the ZX81 ULA circuitry, and as Sinclair had a time limit and a limit on the number of gates in the first generation of ULA chips for the ZX Spectrum, it was not really practical to include the extra circuitry to support both TV standards in the same chip.

Mark

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