Help identifying cap/finding replacement

[digge]

Hi

Trying to find a replacement for a cap for a "motherboard" for a Central Vacuum. Ive tried Google it but seems that i'm unable to find out what the manufacturer of the cap is or find any datasheet for it so i know what to replace it with. Ill attach some images on the cap and the board. This is the second board that breaks for my parents so i thought id try to fix it, since it seems to be the same problem and its not within warranty anymore i think.

As you can see in the pics its rated at 470uF but measures 3.7uF and the ESR on my meter just says ---- so im guessing its in pretty bad shape.

[sofTest]

Re: Help identifying cap/finding replacement

I doubt very much a datasheet for this capacitor can be found. This is a typical cheap Chinese capacitor, often produced under different names for different customers, from the same factory.

As for a replacement, I doubt ESR is important for this application, so personally I would have gone for endurance. This based the location close to the transformer (= heat). I don't know where you buy your capacitors, but you being Swedish and if Elfa is your source, my first recommendation would be Rubycon ZLH and second Suncon (Sanyo) AX. You have not given dimension of your capacitors, so please observe before ordering.

[turbozutek]

Re: Help identifying cap/finding replacement

I might even be tempted to look for a 135'c rated cap for that application. Central vacs are not exactly cool running.

And yeah, an orange inside a sock would work better than that Chinese crap in there, so I don't think the replacment cap will be too fussy about ESR specification.

[Toasty]

Re: Help identifying cap/finding replacement

Linear power supply, not a switchmode type. What sofTest is correct. Any decent brand cap with good ripple characteristics @ 50 - 120 Hz would be fine. ESR is not important here.

Best Wishes!
Toast

[digge]

Re: Help identifying cap/finding replacement

Thank you for the suggestions, ordered some caps now, lets hope it works after this and the programing of that chip isn't screwed.

[kaboom]

Re: Help identifying cap/finding replacement

Linear power supply, not a switchmode type. What sofTest is correct. Any decent brand cap with good ripple characteristics @ 50 - 120 Hz would be fine. ESR is not important here.

Best Wishes!
Toast

I'll bet that's either a phase control or a soft starter for the big vacuum motor. The EMI filter on the AC line input is further proof. What holds that triac to the heatsink?

That cap is the filter for the small rectified supply derived from that little control transformer. I see 1N4004 diodes for the control power supply. If your line voltage is prone to dips n sags, you could use a 1000u cap there. None of the 'too big a cap' nonsense here- that is a Class 2 transformer.

It appears your board came in two 'versions.' The one you have has the triac to control the vac motor- there was an option of using a relay instead. Looks like DPST contacts would be used instead of MT1 & MT2 on the triac. Naturally, you'd only have on-off control with the relay.

Good luck
-Paul

[digge]

Re: Help identifying cap/finding replacement

This particular vacuum have 4 speed settings on the handle so i bet you're right with there being other revisions of the board with a relay instead.

What holds it in place is a little metal plate with threads and a screw through. Removed it to get access to the underside of the board.

[digge]

Re: Help identifying cap/finding replacement

Swapped out the 470uF cap and the vacuum went back to working like a charm. For future reference i can say that the make is Cyclo Vac and the model is DL 140 SV, just in case someone else have the same issue, since i have 2 boards with the same issue i bet its a quite common problem.