[Voodoochile]

After making erix's version of the Stokes PS PCB, I thought I'd take a crack at making a mock Welborne PS1 PCB:

It is mostly the same, except my bridge bypass caps are .33uF, and the larger caps are Nichion Muse rather than the Elnas that Welborne offers. Same Linear Tech regulators. I also flopped the silkscreen layer and printed that out, ironing it on the topside of the board. There are some discrepancies between the trace side and the screen side, but only a couple near the output end. They have made some revisions to the copper side it seems.

Here is the link to Welborne's PS1.
And here is the link to my other somewhat-similar, the original Father of PS **** PSU.
I have not done any side-by side testing as of yet.

 

[grinch]

i wanted to post in this thread because of the really great title heh. what kind of case are you going to put this one in, an old scanner?

i'm interested in hearing some comparisons. also.. what voltages do these power supplies run at? i'm guessing any voltage you want?

 

[jamont]

Looks good, nice job! Can you hear a difference in PS noise with this version?

 

[Voodoochile]

Quote:

...what kind of case are you going to put this one in, an old scanner?

Heh... I do have an old Scitex flatbed (huge). But no. Maybe an old KitchenAid mixer chassis?

You can wire the toroid for 110v or 220v. I have no specific plans for this one yet.

Jamont- I just finished this at about 1:00 this morning, so all I have done is test it. It's going to be tough for it to be quieter than the original one (father of...).

I am looking forward to comparing it to both my mack-daddy PSU and the simpler stokes psu. My stokes has normal diodes in the single bridge, whereas the other two have dual bridges with soft-recovery hexfreds. Also, the original one has 42,000uF of Panasonic FC caps, while this one has 20,000uF of Nichion Muse caps. The Panasonic giant is actually very fast, as it has quite a bit of film cap in it as well, moreso than the PS1/Welborne knock-off.

 

[jamont]

I should try to put something like this together. Can you recommend a source for the transformer?

 

[Ghostie]

Lookin good!

 

[Voodoochile]

Digikey. A 15v 2.33A is 16.83 (30v at 1.16A), the 18v 2.77A (36v 1.38A) is 18.83. You can wire them up for either 110 or 220 operation. Not cheap, but for a decent toroidal tranny, it's a helluva good deal. They run quiet (Talema, BTW).

edit: Thanks, ghostie!

 

[jamont]

That sounds pretty reasonable for a good toroidal transformer, thanks VC!

 

[Voodoochile]

The total cost was about $75.00 for this. Before anyone chokes, see the Welborne link at the top of the thread.

 

[jamont]

VC, what part do you use for the bridge bypass cap? I'm trying to pick out some and I'm not sure what to get, thanks!

 

[Voodoochile]

You can use these MKP type from BC (philips). Digikey P/N is BC2132-ND. I have these on order for another bridge.

I used another small metallized polypro box cap I had on hand, a .33uf Arcotronics type.

 

[jamont]

Thanks! Ordering parts is harder than actually building stuff...

 

[jamont]

Hi VC-

I notice that you don't have heat sinks in the TO-330 regulators, is that unnecessary for low power applications? I'm working on a layout myself and it would save a lot of space not to use them...

 

[Voodoochile]

Jamont-
I hope this isn't causing you to have many seperate orders!

On my first beefy PS, I used the HS220-ND clip-ons from digikey. They are about .45 each, and just get warm only. That PS was using the 317/337 regulators. This PS1 knock-off uses the LT regulators, which are very low droput. The tabs barely even warm up, even with a 7 volt difference between the input and output voltage. I have not installed anything so far, but am using it with a multiloop amp for now. If I connect this to my KGSS, they may heat up more with the added current draw. That said, the clip-on 'sinks from the first PS will easily fit without moving anything around.

The packages are TO-220, BTW.

If your input voltage is significantly higher than the output voltage (say- anything more than 7 volts

), you will surely want to use something, and if it's more than 10 volts, you will want to get something heavier, or get a smaller transformer. The regs will technically dissipate quite a bit of power, but heatsinking becomes critical as the difference increases. Ideally, they say about 3-4 volts over on the input to provide proper regulation.

It's hard for me to say you don't need them. I don't seem to need them for my application, so far.- while using the Linear Tech regulators specified by Welborne.

My 317/337 PS is driving +/-15.5 volts into a multiloop amp that has four BUF634s per channel, and a pair of 637 OPAs in it. It draws quite a bit of juice for a solid-state amp, and the tabs get hot fast. With even the small clip-ons, they keep 'just warm' to the touch. Maybe 115 degrees farenheight.

If you use the 317 and 337 regs, I would definitley 'sink them, even if the 'sinks are small.

 

[jamont]

I'm using 317/337 regulators, so it sounds like I should plan on using heat sinks. It's interesting that the LT regulators don't seem to heat up as much. Those are probably better parts, I'll go with them next time.

Thanks again for your help VC, exactly what I needed to know. Now for another parts order...