Using the 48v Phantom on JLM PSUs to drive 24v (etc.) relays

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I got one of the JLM PSUs (The power station one) - to drive a number of 18-0-18v boxes (eg Calrec EQ)
You can set the voltage to be anything from +/-2v to 37v on 2 rails.. (so I set mine to +18/-18)
In addition I am using relays on my calrec (24v) and I wanted to use the 48v phanotm rail with adjustments to drive the relays...

Joe has kindly provided the following info on how to do it...
He has also provided info on using the rail for any relay (or what you have) from +5v to 34v.


The above two images show how to disable the pump charge and
use the 48v power rail as an extra +5v to 34v rail. You will need a 22vac -
0v - 22vac transformer to get enough volts for the 24v relay rail.

Do not fit the parts with a cross on them or the 3 large caps that will be linked over. Also change the zener to a normal 1N4004 or 4007.
And on the power station link out the 47ohm resistor as well.

JLMACDC%20low%20volts%20on%2048v%20rail.jpg

PowerStation%20low%20volts%20on%2048v%20rail.JPG
 
Right - built it...
Only change I did was to use Bourns trimmer pots with the screwdriver change rather than the 25 step stuff..

One little problem (well a big one)
Checked all my soldering - looks fine...

The negative rails - no problem at all.... set them via the trimmer at -18 and -18
However the positive rails....

There are supposed to be three positive rails - these should be set at +24, +18, +18
(the circuit change is to change the 48v slow ramp into a 24v line)

If I set any one of the positive rails then that becomes the range of all three positive rails...

i.e. set the 24v to 24v and all three go to around 24v...
Set the third 18v to 18v and I can'g get more voltage ont he 24v rail past 18v...

I am doing something daft - anybody want to point me in the right direction...
 
Interesting problem.
Make sure the 24v rail is not connected directly to the 18v rails on the calrec as this would do what you describe. If 2 regulator outputs are connected the higher one will turn off the lower one and take over from it.
The 48v (now 24v) is independent so should have no control over the other rails otherwise.

What power transformer are you using ?
How is it connected to the Power station? one 0v and AC in or 0v and both AC ins etc?
Do you have a circuit or PCB overlay for the Calrec you are talking about?
 
Joe I haven't connect it up to the Calrec....
Just stuck a multimeter in the bottom right pin of the DC out... and then check pins 1-3 above it (the three positive voltages) - pins 4 and 5 above that (the negatives are fine)

I haven't connected any 0V on the AC line - it's just ont he bench at the moment - there are no 0V lines anywhere...
(there will be once it is in a box)

Using a 18-0-18 medium VA torroid - AC voltage looks fine
 
There would be the problem
Your Toroid should be connected 18vac to AC in, 0v centre tap to 0v at AC end, 18vac to other AC in. Just like the schematics show. You cannot run the Powerstation or AC/DC without a centre tap going to the AC end 0v in.
If there is nothing connected to the AC 0v then the output voltages will shift as the 0v has no reference point and can move up and down depending on the load of each regulator.
 
Joe
Sorry for the blonde moment
Connected up as suggested
Everythign fine
Now have a lovely little PSU delivering

+24v, +18v, +18v, 0v, -18v, -18v

I ran out of space on the board due to using some bigger screw connectors that I had in my spares box - so I soldered the non electro capacitor (I used a little Wima MKS) underneath the board
Also used 1N4007s instead of 1N4004s (I ran out of them - but I think the 1N4007s where a higher voltage rating, I think, - so I figured they should be fine)
Also used a side trmmed Bourn pot (not ideal - cos you have to screwdriver adjust between the two small Electro capacitors)...

Cos the highest voltage rating was only 24v - I think I used 35v caps... for some og them (I forget which ones...)

But everything was built using bits from my spares box - so apart from the cost of the boards - it didn't cost me a penny
 
BTW ...
Panasonic FCs will fit in the small electro cap footprints
The big electros - the footprint is too small for FCs.

I used a load of purple Elnas I had around.
 
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