The Sinclair QL Forum

... if both QLs are equipped with Teroid switching regulator ? Would the better efficiency of the switching regulator be enough to reduce power consumption by half ?

These PSU are difficult to come by so using a single one for two QLs would be nice.

What if one of these QLs has a GoldCard ? (My understanding is that the Goldcard is powered directly by the 9V coming from the PSU and has its own 7805 regulator). Would power consumption for that QL be higher than a BBQL ?

François

You should consider also the 16V AC input divided between 2 QLs... I know the AC power requirement is very low, but would it be sufficient once split?

Even if it worked for some time, I wouldn't load that good 'ol PSU with nearly twice its rated current. The switching regulators do in fact slightly reduce current input, but not that much.

Even if you made it work, you'd still be faced with the nonstandard power connector.

Stitching together a 9V-/15V~ PSU actually isn't that hard. Buy a cheap Chinese 9V PSU plus a small 240/15V print transformer. Solder/Glue that to a piece of perfboard, add a case, voila, you're done. (And still faced with no proper connector).

Tobias

tofro wrote:Even if it worked for some time, I wouldn't load that good 'ol PSU with nearly twice its rated current. The switching regulators do in fact slightly reduce current input, but not that much.

Even if you made it work, you'd still be faced with the nonstandard power connector.

Stitching together a 9V-/15V~ PSU actually isn't that hard. Buy a cheap Chinese 9V PSU plus a small 240/15V print transformer. Solder/Glue that to a piece of perfboard, add a case, voila, you're done. (And still faced with no proper connector).

Tobias

The power connector is not a problem, I'll manage. Routine work for me. I understand now that the Teriod regulator is not reducing overall power consumption that much. So not a good idea.

I have thought about putting a PSU together using a 15VAC + a 9VDC PSU, but I must admit I don't know how to wire both together, i.e. 9 volt ground is common to what 15VAC wire ?? Any ? Also, what would be the required current capacity for both PSU ?

F.

FrancoisLanciault wrote:

tofro wrote:E
I have thought about putting a PSU together using a 15VAC + a 9VDC PSU, but I must admit I don't know how to wire both together, i.e. 9 volt ground is common to what 15VAC wire ?? Any ? Also, what would be the required current capacity for both PSU ?
F.

Common GND is in fact either side of the AC transformer output, which one doesn't matter (BTW I managed to scavenge several 12V transformers from some cheap Chinese Christmas lights my wife wanted to throw away - They seem to be a good source for this and are even outdoor rated ). The Tetroid (as well as the original) regulator will not source much more than 1, maybe 1.5A from the 9V=. I guess the AC currrent is way less, maybe 0.5A or even less.

Tobias

tofro wrote: Common GND is in fact either side of the AC transformer output, which one doesn't matter (BTW I managed to scavenge several 12V transformers from some cheap Chinese Christmas lights my wife wanted to throw away - They seem to be a good source for this and are even outdoor rated ). The Tetroid (as well as the original) regulator will not source much more than 1, maybe 1.5A from the 9V=. I guess the AC currrent is way less, maybe 0.5A or even less.

Tobias

So, is it 15VAC, 16VAC or 12 VAC that is needed? Or any of the above ?

Francois,
I might have a last spare PSU still available. It's handmade and provides more power (2.5 Ampere or more). I've sold 4 similar PSUs. A person asked for it years ago. I may ask that person: he might no longer be interested.

Cristian wrote:Francois,
I might have a last spare PSU still available. It's handmade and provides more power (2.5 Ampere or more). I've sold 4 similar PSUs. A person asked for it years ago. I may ask that person: he might no longer be interested.

Sure I would be interested, however I am located in Canada, so it needs to be 110Volts... Also shipping consideration might make the final cost quite high compared to an home brewed solution.

François

FrancoisLanciault wrote:it needs to be 110Volts

BIG problem

Cristian wrote:

FrancoisLanciault wrote:it needs to be 110Volts

BIG problem

Figured it might be but thanks for the offer!