PSU alternative?

Nagging hardware related question? Post here!
User avatar
Lurch666
ROM Dongle
Posts: 14
Joined: Sun May 10, 2015 3:54 pm

Re: PSU alternative?

Postby Lurch666 » Fri May 15, 2015 11:35 pm

Good question.
I've collected quite a few retro computers and the Q.L. was one of the few Sinclair computers I have never owned so I since a lot of the computers I've collected are ones I could never afford when I was younger I finally got a Q.L.

Once I've got it reading microdrive tapes I'll have a mess around with the business software that came with it and then see about getting some games on it.


You rang......
User avatar
Derek_Stewart
Aurora
Posts: 771
Joined: Mon Dec 20, 2010 11:40 am
Location: Runcorn, Cheshire, UK

Re: PSU alternative?

Postby Derek_Stewart » Thu Jul 09, 2015 6:22 pm

Hi,

I only have 1 QL PSU for 3 QLs, so I tried to buy another, I was shocked at the prices on eBay for a QL. Which I am not prepared to spend over £300 for a QL and PSU.

So I thought about a more update to date QL PSU, as mentioned earlier in the thread, there are designs available and the case could be reproduced by laser scanning the original case. Assuming no copyrights are in force.

I thought maybe the PSU plug connecting the QL would be hard, but is really just a 3 pin plug with a shaped key on top.

Would there be a market for this...


Regards,

Derek
RWAP
RWAP Master
Posts: 2244
Joined: Sun Nov 28, 2010 4:51 pm
Location: Stone, United Kingdom
Contact:

Re: PSU alternative?

Postby RWAP » Thu Jul 09, 2015 9:04 pm

Most definitely there would be a market for a replacement PSU.

Don't worry about the design rights on the PSU case - they expired some tme ago, although you would need permission to put Sinclair on the case...


User avatar
1024MAK
Gold Card
Posts: 459
Joined: Sun Dec 11, 2011 1:16 am
Location: Looking forward to summer in Somerset, UK...

Re: PSU alternative?

Postby 1024MAK » Fri Jul 10, 2015 10:31 am

If a forum member would like me to take the design in this post from a theoretical design to a built and tested design, let me know.

Mark


QL, Falcon, Atari 520STFM, Atari 1040STE, more PC's than I care to count and an assortment of 8 bit micros (Sinclair and Acorn)(nearly forgot the Psion's)
User avatar
Derek_Stewart
Aurora
Posts: 771
Joined: Mon Dec 20, 2010 11:40 am
Location: Runcorn, Cheshire, UK

Re: PSU alternative?

Postby Derek_Stewart » Fri Jul 10, 2015 10:39 am

1024MAK wrote:If a forum member would like me to take the design in this post from a theoretical design to a built and tested design, let me know.

Mark



Hi Mark,

Looks like you have done most of the hard work.

Do you think the case needs to look similiar to the old PSU, without the Sinclair branding.


Regards,

Derek
User avatar
1024MAK
Gold Card
Posts: 459
Joined: Sun Dec 11, 2011 1:16 am
Location: Looking forward to summer in Somerset, UK...

Re: PSU alternative?

Postby 1024MAK » Fri Jul 10, 2015 10:50 am

I think this is an individual taste question. Myself, I'm not bothered about a replacement PSU looking like a Sinclair PSU, as the PSU normally lives out of site on the floor, or behind the monitor/TV.

When I built a replacement PSU for a Memotech MTX, because it is hard to get an off the shelf transformer with the required rating, I went for a larger transformer, so had to use a much larger case. This larger case allowed plenty of room inside to fit a IEC mains input connector (for a mains lead), the small strip board (that holds the rectifier diodes, smoothing capacitors and a fuse) and the DC-DC converter. The larger case also makes it easier for home construction.

Mark


QL, Falcon, Atari 520STFM, Atari 1040STE, more PC's than I care to count and an assortment of 8 bit micros (Sinclair and Acorn)(nearly forgot the Psion's)
User avatar
dilwyn
Mr QL
Posts: 1231
Joined: Wed Dec 01, 2010 10:39 pm
Location: Wales
Contact:

Re: PSU alternative?

Postby dilwyn » Fri Jul 10, 2015 10:59 am

Derek_Stewart wrote:
1024MAK wrote:If a forum member would like me to take the design in this post from a theoretical design to a built and tested design, let me know.

Mark



Hi Mark,

Looks like you have done most of the hard work.

Do you think the case needs to look similiar to the old PSU, without the Sinclair branding.


Personal taste would be for as small a PSU case as we could. While I appreciate some people would want it to look like a Sinclair one (as far as copyrights etc allow), I find the original Sinclair one too big and clumsy for my desk, it ends up gathering dust and being kicked on the floor out of the way.


Dilwyn
All things QL: see www.dilwyn.me.uk
User avatar
tofro
QL Wafer Drive
Posts: 1154
Joined: Sun Feb 13, 2011 10:53 pm
Location: SW Germany

Re: PSU alternative?

Postby tofro » Fri Jul 10, 2015 11:02 am

Right, same here.

What definitely should look like the original is the QL-side plug :) - That's non-standard (At least I haven't seen one like that anywhere) and would probably be a 3D-print job - Contacts could be made from brass tubing pressed into the connector and soldered to the wires.

I guess most people wouldn't really accept anything that doesn't fit into an un-modified QL.

Tobias


User avatar
1024MAK
Gold Card
Posts: 459
Joined: Sun Dec 11, 2011 1:16 am
Location: Looking forward to summer in Somerset, UK...

Re: PSU alternative?

Postby 1024MAK » Fri Jul 10, 2015 12:35 pm

If small is what is wanted, then we need to ditch a 50Hz iron cored transformer and use a mains switch mode power supply (SMPS) like this one. I strongly recommend buying from a normal retail outlet. Some of the mains SMPS available on line (from for example eBay) are cheap rubbish and do not comply with European or British safety requirements.

The output from the 9V DC PSU then needs to be fed into a small module (in a small box). This will convert the 9V DC into an AC output, which will then feed the 15V AC input.

But as I have not thought about the design of this module/circuit, let alone built or tested it, it will be a while before I post the details...

Mark


QL, Falcon, Atari 520STFM, Atari 1040STE, more PC's than I care to count and an assortment of 8 bit micros (Sinclair and Acorn)(nearly forgot the Psion's)
User avatar
vanpeebles
Commissario Pebbli
Posts: 1762
Joined: Sat Nov 20, 2010 7:13 pm
Location: North East UK

Re: PSU alternative?

Postby vanpeebles » Fri Jul 10, 2015 1:00 pm

Can it have a blue LED too? 8-)



Return to “Hardware”

Who is online

Users browsing this forum: Bing [Bot] and 1 guest