official GDIY51PSU Help & Support Thread

[dandeurloo]

I just got back from a vacation and I will be trying to finish the PSU tonight or tomorrow.  What value resistors do I need to use for the LEDs?

 

[zayance]

What value resistors do I need to use for the LEDs?

Schematic on page 1 of this thread

 

[dandeurloo]

3. You can power the LEDs as in the below picture. Apply ground to LEDs by using a black wire. Then power each LED by using a series resistor from its respective fuse immediately below.

Sorry if this seems obvious but I looked on the schematic again and I don't believe the "series resistors" are on the schematic. I see R3, R13, R23, R33, R43 but I'm not sure those are the values in the picture above used to powering the LED's.  Am I wrong? 

If they are the same ones, could/should I pull them off of the PCB board since they aren't being used in that position and use them on the front panel?  Or should I just pull a tap off of the them from the PCB board.

Seems to me it would be easier and cleaner to pull them or just use new ones if these are the values needed for jumping the power to the LEDs on the front panel as in the photo?

Thanks guys for you help.

 

[[silent:arts]]

Hi Dan,

the frontpanel LEDs are not shown in the schematic. leave the LEDs and their resistors on the PCB, they don't hurt (they are there to have a min. load).
you want the frontpanel LEDs after the fuse. the resistor depends on your LEDs, if unsure take the same values like on the PCB.

 

[dandeurloo]

Ok, that is what I thought!

For the LEDs in Cemal's kit should I use these values to be on the safe side. 

+48v use 4k7
+-24v use 2k2
+-16v use 1k5


I just want to make sure I got it right before I move on.

 

[jsteiger]

Ok, that is what I thought!

For the LEDs in Cemal's kit should I use these values to be on the safe side. 

+48v use 4k7
+-24v use 2k2
+-16v use 1k5


I just want to make sure I got it right before I move on.

Yes, those are the correct R values Dan. I'm not sure what LED's Cemal has supplied but I'm sure they will be fine.

 

[dandeurloo]

Thanks!

 

[dandeurloo]

51x team.  I'm super close to having this up and running!  I have one more quick question about grounding for the PSU.

Is it better to run the LED's negative leads to the ground (pin 2) on the XLR and run the Ground from the PCB to the same pin 2 so the grounds meet at the xlr or is it better to try and run the LED's back to the PCB then from the PCB to the XLR.  I'm not sure that it matters but I figured you guys have something in mind as far as optimal grounding.


Also, should I run both Chassis from the PCB to Pin 1 of the XLR or does it not matter?

Thanks

 

[sahib]

Hi Dan,

Hello from Istanbul.

Yes, it would be more convenient to run the ground from the XLR.

I wouldn't be fussy about the chassis' either. But run them to the XLR, it does not hurt.

 

[dandeurloo]

hey guys, I powered it up!  Nothing blew but my Led's on all of the negative legs don't light up.  Any ideas on where to check?

I could post pictures if it would help. 

Also, is there any calibration that needs to happen with the trimmers on the PSU?

 

[jsteiger]

Dan, try turning them around. The will work then. 

Did you insulate the (4) 350 regulators? Are they connected to a common heatsink? Not sure what you got from Cemal.

 

[dandeurloo]

I'm pretty sure they are in the proper direction!  I'll do another look.

I did get some stuff from Cemal for isolating the 350's.  Should I maybe put the negative on one heat sink and positives on the other?

 

[dandeurloo]

just checked Led's are in properly.  Flat side to the ground and Resistor carrying power to the round side!


EDIT*****

I thought  about what Jeff was saying.  I at first thought it was a joke but it got me thinking.  Since its the Negative rail it does travel the other way.  So I flipped the LED around and it worked.  It is always something simple.

Thanks Guys!

 

[pacemaker]

Hi guys,
i am finishing a 51X PSU i bought from another member,
he bought the PSU components kit from Ptownkid,
the regulator are LM317T, i'm not sure if i have to change them for some LM350T
i've read JDB,Volker and jeff posts, but i'm not sure of the answer,
plus, my local shop sell LM350T for 2.5€ each !!!
and mouser are out of stock.
should i keep my LM317 ?
regards,
Francois

 

[dandeurloo]

I was told by all the 51x guys to use 350's.  I bought the kit from Ptown as well so I had to buy some 350's because Ptown wouldn't update the kit.

 

[sahib]

Pacemaker,

LM317 would certainly work but I would replace them with LM350.



Dan,

First check to see if you have voltage output on the negative rails at all.

Then make sure if you connected the negative rail regulators correct way round. It gives me an impression that you did not.

As long as the regulators are insulated from the heatsink you should not have any problems either. Obviously using a seperate heatsink is superior but not esential.

Disconnect the psu from the mains and check if there is a short circuit between the tabs of the regulators and the chassis. Both the heatsink and the case surfaces are anodised, therefore you may not read a short circuit if you check it on the surface. Check it between the regulator tab and the mounting screw of the heatsink to the chassis.

 

[jsteiger]

Dan, you are not talking about LED's mounted to Volker's pads on the PCB, you are talking about point to point for the front panel of the 51x PSU case right? Like the one in Cemal's pic a few posts up? Each current limit R (R3, R13, R23, R33, R43) is always on the anode side of all the LED's. For the two negative rails, that R goes to ground. If you take a close look at the skiz, you will see what I mean on the dif between the positive rail and a negative rail. Volker has all of this accounted for on the PCB mount LED's. You will have to wire your point to point components the same way.

Does that all sound confusing? Sorry of so. 
Best, Jeff

 

[Sammas]

Hi chaps,

I received my rack yesterday (thanks Cemal!). I was a little startled by the UPS man, I wasn't expecting it to arrive for at least another week. It is already build. I didn't think a kit could surpass JLM in terms of quality and organisation but I think this just might take the prize!

A question regarding PSU's though. I only need +/-16v (as the rack is almost full already!) so I'm using a JLM power station. It is capable of 1.5amp per rail and will to powered via a 160va 18v transformer.

Regarding rail LED's and fuses, is it just a case of wiring a fuse in series to each PSU rail output followed by an LED with current resistor going to ground?

 

[sahib]

Good to hear you got it safe and your comments.

In terms of the psu wiring, yes, wire the fuses in series to each rail. In terms f the current limiting series resistor for the LED it does not make any difference whether it is connected to the ground or to the rail.

 

[Ptownkid]

I was told by all the 51x guys to use 350's.  I bought the kit from Ptown as well so I had to buy some 350's because Ptown wouldn't update the kit.

It has been updated now. I'll send you a pm and work out a way to compensate you for your troubles.

Jeff...where are you at on the psu transformers?