Looking for electrolytic caps 5000uF 100VDC with M8 mounting stud in Germany

[frozenfrogz]

Dear all,

lately I bought another Oltronix B60-1T Lab Pac power supply. Sadly this on has at least one leaking output capacitor. I cleaned up the mess - luckily the electrolyte only gunked up the bottom cover - no other parts were harmed. The original part is 40mm in diameter, 83mm tall and features a threaded fastening stud. There are two caps in parallel.

The part is labeled:
Wicon (?)
electrolytic capacitor
5000uF
100 V.DCW
Type KG1 (?)

Can any of you recommend a suitable replacement? I looked at a lot of caps and it seems I will have to opt for 6800uF or 4700uF. The ones with mounting stud are hard to find though.
I might also replace both caps with just one 10000uF cap if it is not bigger than 45mm in diameter and no taller than 120mm.
If there are no parts available with mounting stud I can turn a suitable mounting bracket on the lathe - stud option is preferred though

Thank you and kind regards!
Frederik

P.S. Here are two parts I found, but no threaded mount: Rubycon Nippon Chemi-Con

P.P.S. I already bought some Sangamo 4700uF 100VDC caps via small ads but I was fooled by the pictures. These are HUGE! (76mm diameter, 105mm tall + screw terminals, but no mounting stud) So if anyone is going to build a big bug zapper: Send me a message

[Benta]

Wicon Kondensatorfabrik was a Danish manufacturer of electrolytic and bipolar caps, but AFAIK no longer exists. Finding a direct replacement or NOS is not really plausible.
Good luck hunting

[Twoflower]

Can you post the specs and/or pictures of the PSU? Especially the max. output voltage. Because having a 100V filter cap in there sounds interesting.

5000uF are very uncommon these days. So you should decide 4700uF or 6800uF. And if it's a linear (no switching) PSU and the blown cap is the main filter cap the exact value isn't very important. It has some influence on the ripple under load. And with 'modern' caps might be able to life with 4700uF.

How about this one:
https://www.reichelt.de/Becher-Elkos/4-700-100M8/3/index.html?ACTION=3&LA=446&ARTICLE=2450&GROUPID=3146&artnr=4.700%2F100M8&SEARCH=4700uf%2B100v

[MadTux]

I would go for the 6800uF ones, bigger is better

I'm usually rather creative when replacing electrolytic buffer caps in PSUs. They will go bad in 20years again, so why bother finding exact replacements if you can bodge in something cheap that works just as well.

[edpalmer42]

A few years ago I had to replace a stud-mounted capacitor.  Rather than try to find one (are they even manufactured in that form factor any more?), I put a long bolt through the mounting hole and used cable ties to attach a radial capacitor to the bolt.  It's a bit ugly, but it works fine.  If there isn't room for the capacitor to sit beside the bolt, maybe you could use smaller capacitors in parallel and mount them around the bolt.  Heatshrink tubing would help stabilize the assembly.

Ed

[frozenfrogz]

The PSU is 60V 1A max. And yes, it is a linear power supply.
Specs, schematics and pictures are in this thread.
That ROE cap looks about right

Edit: Last post in the thread is a link to an imgur album I uploaded, in case you like looking at 1960s tech internals. These pictures are from the other unit I have (fully working and no leaking caps).

[Twoflower]

That's one nice PSU. Good catch. Yes the 100V make sense. I was a bit surprised to see such high voltage. But with up to 60V output voltage that is required.

And while you're in there: Look out for other caps showing some unusual signs. I'm a bit torn to recommend to pro actively replace the other caps or not. The problem is you can't (reliable) measure them in circuit.

In case you need it I found the schematic of your gem here: http://bkg405h.se/OLTRONIX_LABPAC_B60-1T.htm (click on the image to get a very high-res image)

[mariush]

I just checked the pictures in your imgur album and it looks like you have plenty of room there for taller capacitors... you could just solder longer wires.

Farnell has lots of capacitors but not necessarily with that spacing and m8 studs... but what's wrong with just soldering the wires?

epcos 4700/100v 35x40 : http://uk.farnell.com/epcos/b41231b9478m000/cap-alu-elec-4700uf-100v-snap/dp/1839295
vishay 5600/100v 35x45 : http://uk.farnell.com/vishay/mal225659562e3/cap-alu-elec-5600uf-100v-snap/dp/2474604

TME.EU has a listing (but not stocked, though ask maybe they get for you) Samwha 4700/100 WITH screw terminals , 35mm x 60mm : https://www.tme.eu/en/details/gt2a478m35060sb/screw-terminal-and-others-el-capacitors/samwha/

Otherwise snap-in ones

(a bunch of 4700uF ones you can find your self)

nichicon LS 3000h/85c 4700/100v 35x40 : https://www.tme.eu/en/details/lls2a472melc/85c-snap-in-electrolytic-capacitors/nichicon/
nichicon LS 3000h/85c 5600/100v 35x45 : https://www.tme.eu/en/details/lls2a562melc/85c-snap-in-electrolytic-capacitors/nichicon/
nichicon LS 3000h/85c 5600/100v 35x50 : https://www.tme.eu/en/details/lls2a682melc/85c-snap-in-electrolytic-capacitors/nichicon/

[frozenfrogz]

Thanks guys for all the suggestions
Re. schematic: I managed to get a hold on a copy of the service manual. It is a very nice read, even if you do not own one of those! Link to a PDF version I put together is in the B60-1T thread.

I will screen through the suggested parts and keep you posted when the unit is back up running.

Re. caps without stud: I consider using other form factors, but if I end up using the simple type without studs, I do not want to go the zip-tie and duct-tape route. The caps will get some custom mounts then that utilize the original mounting holes and Bakelite nuts.

[2N3055]

Instead of screw (stud) mount type you might want to take a look a these:

https://www.tme.eu/en/details/als30a103de063/screw-terminal-and-others-el-capacitors/kemet/

And corresponding mounting clamp...
 https://www.tme.eu/en/details/2736/screw-terminal-and-others-el-capacitors/kemet/

These are pro grade caps for exactly this purpose.. They should last you years to come..

Regards,

Sinisa

[frozenfrogz]

Since the 10.000 µF 100VDC Kemet ALS type were on backorder (as were the 6.800 µF ones) when I wanted to get them, I ended up ordering two 4.700 µF 100VDC caps.
KEMET ALS31A472DE100

I turned two small aluminium mounts from some stock material to hold the caps in place and attached them with a dab of hot glue.
Since I did not have fitting connectors for the screw posts I made them from thick braided wire.

The lab supply still needs to be calibrated, but that is a job for another day