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Universal power supply board

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cowasaki:

EDIT: Please see latest design in post number 4......


I'm building a universal PSU PCB for my projects so I can have a load made and build them differently for whatever I'm making.

If I need current limiting I'm thinking of an LT3080 but if I need to limit the current on the negative rail is this the correct setup?

I'm happy with the rest of the project and the values are still for sorting.....

StillTrying:
If you reverse D13 and D14 the +Ve current limit would look correct to me.

I don't think there's any way to make a -Ve current limit using a +Ve regulator with a center tapped transformer, you'd need 2 separate floating windings and bridges at least.

cowasaki:
Whoops! Re D13 & D14, that was a typo!! I think I swapped them round whilst moving them about :-)

My original design started with two sets of diodes and I thought that I might need to take those outputs and have two identical current limiting circuits then connect the pos of one to neg of the other and create the two from that but then I thought I’d just ask as there are a lot of people on here with much more experience than me. I may well do the current limiting with a 78 & 79 then go to the voltage regulation OR back to 8 diodes and use a couple of 78s. I’m trying to make a power supply board that I can have 25 made of and use for virtually anything I need by fitting the right components. Still might go back to 8 diodes.....

cowasaki:
OK, I've completely redesigned the entire board now.  The whole idea is that this is a universal board that I can use to power my projects.  I will probably have it made 20+ times and just keep a stock of them.  In most cases only a few of the options will be installed.  So I might have just the first bank of diodes and the LT3050ET or I might have a positive and negative 12V rail.  There is an optional current limiter as well.

Can anyone see any obvious issues?

Kleinstein:
Using a L7818 for current limitation is really odd, as 18 V over the current setting resistor is really a lot.
If at all a LM317 would be suitable, but it has a different pinout.
The 3 pins regulator already have a current limit inside, though fixed, but there are a few types to chose from:
78Lxx for some 100 mA
78Mxx for some 500 mA
78xx  for some 1000-1500 mA
78Sxx for some 2 A
For just protecting a circuit in case of a short or failure, this is often good enough.

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