The Sinclair QL Forum

Sparrowhawk wrote:Drat, I thought that one said 5v, I'm not sure why I got that link.

Maybe I should not have searched after a ten hour work sprint.

Hi,

I have sent you an email with recommendations, but a UK 5v 1a Power Supply can be bought on eBay:

https://www.ebay.co.uk/itm/UK-3-pin-Plu ... 2749.l2649

I use that Power Supply and the Periexx PS/2 Keyboard and Mouse, all work perfectly, with the Q68/Belkin PS/2 Splitter.

Please note that if the Keyboard is connected to the Green Mouse port of the Belkin PS/2 Splitter, then the Q68 will not boot at all, it stops on the Boot Screen after displaying the PC.CLOCK.

This is the reason I colour coded the PS/2 Splitter to avoid wrong connection.

I also took the decision not supply a power supply for the Q68, mainly because I can only get UK power supplies at reasonable prices.

If anyone wants a power supply that will work with the Q68, I can supply this on request.

Thanks all.

Derek, I have ordered that PSU, thank you for the eBay link. I'd found another one on Amazon this morning but was almost too embarrassed to ask here in case I got it wrong again.

Been a busy morning reading about regulated, switched, stabilised, amps, voltages, watts, the dangers and pitfalls of getting it all wrong etc.

I think I'll also order that keyboard and mouse, as the Dell keyboard is so huge.

I'll keep you all posted - I'm sure you'll be anticipating my next cock up with great amusement!

I follow the reasoning that Peter over estimated our abilities in this area.

Dave wrote:I follow the reasoning that Peter over estimated our abilities in this area.

hah, too true in my case.

Dave wrote:I follow the reasoning that Peter over estimated our abilities in this area.

No, I simply assumed the Q68 would ship with power supply.

Pr0f wrote:Is there any protection on the 5V input against over voltage or reverse voltage?

Not onboard. There is a header with 5V input, 5V output and ground, where additional protection or other power related circuitry could be added.

[quote="Peter]"
No, I simply assumed the Q68 would ship with power supply.[/quote]

So I would required to stock the following power supplies:

UK: 240V 5V
EU: 240V 5V
USA: 110V 5V
Rest of World: No idea of the mains electricity in every country.

Too many options.

Derek_Stewart wrote:UK: 240V 5V
EU: 240V 5V
USA: 110V 5V
Rest of World: No idea of the mains electricity in every country.

Too many options.

Yes I know Derek. There have not yet been damages by wrong supply, no major problem.

Maybe it would be an option to offer a USB to 2.1 mm cable, so people can use USB style supplies. I use an angled version like this:

Peter wrote:

Derek_Stewart wrote:UK: 240V 5V
EU: 240V 5V
USA: 110V 5V
Rest of World: No idea of the mains electricity in every country.

Too many options.

Yes I know Derek. There have not yet been damages by wrong supply, no major problem.

Maybe it would be an option to offer a USB to 2.1 mm cable, so people can use USB style supplies. I use an angled version like this:

USB21cable.jpg

I had an asus transformer tablet that had a charging lead terminated in the standard USB type A male, but the charger / power supply provided a USB killing 21V ! Such adapters are I think quite rare, but even that solution can come to grief.

Peter wrote:

Derek_Stewart wrote:UK: 240V 5V
EU: 240V 5V
USA: 110V 5V
Rest of World: No idea of the mains electricity in every country.

Too many options.

Yes I know Derek. There have not yet been damages by wrong supply, no major problem.

Maybe it would be an option to offer a USB to 2.1 mm cable, so people can use USB style supplies. I use an angled version like this:

USB21cable.jpg

Hi Peter,

When started making the Q68, I made USB A to 2.1mm x 5.5 mm plug. Which pluged into a 5v 2a Samsung phone charger.

I can easily source the cable and supply, if that is required.

I had an asus transformer tablet that had a charging lead terminated in the standard USB type A male, but the charger / power supply provided a USB killing 21V ! Such adapters are I think quite rare, but even that solution can come to grief.

To get that charger in 21v mode you need to negotiate with it, by default it runs at 5V.