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-   -   1st cap heats up... (http://www.diyaudio.com/forums/tubes-valves/86809-1st-cap-heats-up.html)

JojoD818 20th September 2006 01:57 AM

1st cap heats up...
 
the 1st cap of my test psu heats up. it's a 4.7uf/450V electrolytic and is used in a setup like this:

280-0-280->5y3gt->4.7uf->1.8K->220uf->2.2K->220uf->load.

the load is constant at 20mA. is it too much ripple?

AJT 20th September 2006 02:29 AM

what is the voltage accross that cap?

JojoD818 20th September 2006 02:35 AM

i forgot to mention...

around ~330V max during warm-up and ~310V after 60 secs.

djQUAN 20th September 2006 03:19 AM

slightly OT: hey jojo, do you know where to get tubes in our area?

ray_moth 20th September 2006 07:31 AM

As long as you're sure the cap isn't getting warm from being too close to some other part that gives off heat, then it could be due to ripple. The first cap must be rated for high ripple current.

JojoD818 20th September 2006 01:33 PM

Quote:

Originally posted by djQUAN
slightly OT: hey jojo, do you know where to get tubes in our area?

hi,

there is Spin Electronics in Mandaluyong, I think Deeco also stocks some tubes.

Quote:

As long as you're sure the cap isn't getting warm from being too close to some other part that gives off heat, then it could be due to ripple. The first cap must be rated for high ripple current.
It is actually near a the 5W 1.8K resistor which feeds the second cap. I will try to put some space between them. I am just worried since out of the three caps, the first cap is the only one that heats up. :hot:

AJT 21st September 2006 02:07 AM

Pacific Electronics near DEECO is a good source for GE tv tubes and japanese 12au7, 6cg7's cost is 250 per tube.

jarthel 21st September 2006 02:10 AM

Quote:

Originally posted by Tony
Pacific Electronics near DEECO is a good source for GE tv tubes and japanese 12au7, 6cg7's cost is 250 per tube.

Where in Manila is deeco and pacific eletronics?

what tubes does spin electronics sell?

any contact number for these places?

thank you.

AJT 21st September 2006 02:22 AM

i am in russia at the moment, sorry...

JojoD818 21st September 2006 07:41 AM

Quote:

Originally posted by ray_moth
As long as you're sure the cap isn't getting warm from being too close to some other part that gives off heat, then it could be due to ripple. The first cap must be rated for high ripple current.
I moved the cap away from the resistor and run the test jig for 10 minutes and the cap really is the one heating up by itself and not through passive transfer.

I guess one solution is to remove that cap completely. :o

:)


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