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Re: QL 34th Anniversary new hardware.

Posted: Thu Jan 11, 2018 4:48 pm
by Dave
Just waiting on one part and some testing... Or you'd have got the big one today. :D

Re: QL 34th Anniversary new hardware.

Posted: Thu Jan 11, 2018 9:07 pm
by johnh
Happy birthday, Dave.

If there are any left, I'd like a Miniplane with 3 connectors.

I'd also like a Minerva upgrade with the standard ROM images.

John Hall

Re: QL 34th Anniversary new hardware.

Posted: Thu Jan 11, 2018 10:16 pm
by Dave
Ok. All the Miniplanes have been reserved. If Paul has sold all his, should I get some more PCBs made? I could just add them to another order for something else and the cost would be quite low.

Re: QL 34th Anniversary new hardware.

Posted: Thu Jan 11, 2018 11:39 pm
by Sparrowhawk
Happy 50th!

Forgive my ignorance, but what exactly is a buck? And where on / in a QL does it go. Is soldering involved?

.

Re: QL 34th Anniversary new hardware.

Posted: Fri Jan 12, 2018 4:10 am
by Dave
You know that big black heatsink behind the microdrives? The little hot component on there is the 7805, a 5 volt regulator. It's grossly inefficient, and all that wasted energy is turned into heat.

A buck regulator is for practical purposes a switched, high efficiency transformer. They are much more efficient - 92-96% is common. My design is 96% efficient.

This means two things for your QL. First, there's much less heat behind the microdrives. Second, all that heat WAS energy drawn through the power brick from the wall. The load at the power brick is less, and your meter runs a bit slower. It's basically replacing 80s components with 2000s components from modern electronics.

Re: QL 34th Anniversary new hardware.

Posted: Fri Jan 12, 2018 9:20 am
by Derek_Stewart
Dave wrote:You know that big black heatsink behind the microdrives? The little hot component on there is the 7805, a 5 volt regulator. It's grossly inefficient, and all that wasted energy is turned into heat.

A buck regulator is for practical purposes a switched, high efficiency transformer. They are much more efficient - 92-96% is common. My design is 96% efficient.

This means two things for your QL. First, there's much less heat behind the microdrives. Second, all that heat WAS energy drawn through the power brick from the wall. The load at the power brick is less, and your meter runs a bit slower. It's basically replacing 80s components with 2000s components from modern electronics.


Hi,

Do you mean:

Sinclair QL Power Module ( 7805 replacement )

134x134x28469_QL,P20power,P2001_153px.jpg.pagespeed.ic.7xbRqH1UfU.jpg
134x134x28469_QL,P20power,P2001_153px.jpg.pagespeed.ic.7xbRqH1UfU.jpg (25.01 KiB) Viewed 324 times

Re: QL 34th Anniversary new hardware.

Posted: Fri Jan 12, 2018 10:35 am
by Dave
No, that’s tetroid’s version. Mine is smaller and configurable/adjustable.

Re: QL 34th Anniversary new hardware.

Posted: Fri Jan 12, 2018 9:06 pm
by Sparrowhawk
Hi Dave, thanks for the explanation. I reckon that would be worth having - as long as installation is not too complicated ?

I never have been any good at the hardware front. I just about managed to change the keyboard membrane without killing my bbql, but that's the limit of my tinkering skills.

Re: QL 34th Anniversary new hardware.

Posted: Fri Jan 12, 2018 10:03 pm
by Dave
You take off the top cover, undo the screw in the middle of the heatsink, pull off the heatsink and 7805, plug in the buck regulator, and seal up your QL.

Done!

Re: QL 34th Anniversary new hardware.

Posted: Sat Jan 13, 2018 7:08 pm
by Whopper
Dave,

Can the buck regulator replace the 7805s on the micro drives?

Whopper