The Sinclair QL Forum

After the recent discussion about the power connectors, I have a QL power supply here which is untested (at the moment).... It has some sort of battery backup module inline in the power cable from the PSU to the QL - the power cord has been cut to attach to the battery backup.

The battery backup is quite heavy, so probably not worth the postage...

So, I guess I can offer the short end of the power lead for £2 plus postage - this is only about 10cm (4 inches). Otherwise you could have the power supply as well and I will test it for £5 plus postage - you could then use a standard electrical joining block to re-connect the cables, or if you want the battery backup too I can throw that in, but it will double the weight..

The battery backup mod sounds like a right tinkerers mod, very interesting

RWAP wrote:I have a QL power supply here which is untested (at the moment).... It has some sort of battery backup module inline in the power cable from the PSU to the QL - the power cord has been cut to attach to the battery backup.

I'm intrigued
Any chance of some photos?

But don't get excited and think that I'm interested in buying it. I'm just curious

Mark

The pack probably contains 8-10 1.2v NiCad cells. These can take a charge and then, if power is withdrawn and the cord is still plugged in, they can maintain the QL's logic for a considerable time - great for areas where power is unreliable.

Dave wrote:The pack probably contains 8-10 1.2v NiCad cells. These can take a charge and then, if power is withdrawn and the cord is still plugged in, they can maintain the QL's logic for a considerable time - great for areas where power is unreliable.

Oh, fantastic, I'll have 10 packs then please
(Having just had the umpteenth short power cut in the high winds recently)

I once had a 8V sealed lead acid battery. I forget the Ah rating, but it was around 6 to 8Ah.
Great for powering all things that ran on 8 to 9V DC supplies out of range of the mains supply. Alas, this voltage sealed lead acid battery is not common . Also off the shelf chargers for this voltage are just as hard to find .

There are now cheap DC-DC converters, so you could use a regulated 12V battery charger (that produces 13.8V suitable for a sealed lead acid battery). This feeds a 12V sealed lead acid battery. Which then feeds a cheap DC-DC converter (set with the output to 9V). That can then feed a QL.
Or if the microdrives are not needed, by-pass the 7805 regulator on the QL, set the output from the DC-DC converter to 5V and you will not waste energy (battery life) as heat from the 7805 regulator.

Mark

Some pics of the battery backup....

Don't think I would risk those batteries....

This was actually a commercial item if I remember right - I seem to recall a review from an old QL World (yes the one in the missing box )

Tobias

RWAP wrote:Some pics of the battery backup....
Don't think I would risk those batteries....

Ah, a frequency precision unit. never actually seen a real live one, only in pictures.

This was mentioned in Quanta Vol 4 Issue 8 page 23 according to the index, although I haven't a copy of that issue to hand to know what it says.

Dibbs