I was redoing my idiot lights and a capacitor attached to my clock area broke off (rusted somehow...). It is 25v 47uF. Apparently, Radio Shack (the only one out of 3 I could find that actually had capacitors) decided to carry every other capacitor but that one. However, I did find a 50v 47uF (and I think a 35v 47uF) that looked the exact same. Could I use that as a replacement?

Cliff notes: Can I use a 50v 47uF in place of a 25v 47uF capacitor?



P.S. Radio Shack blows.

 

Paging AaronCake. You should try Digikey et. al.

(Edit: Aaron made me use my brain. Trust him.)

 

Digikey.com has proper capacitors from $0.15-$1.50 depending on some measurements you didn't give. Since you're smart enough to fix it, you're smart enough to measure it and find the one you want from them. Enjoy.

 

50V is fine.

But a general tip regarding electronics is to NOT SHOP AT RAT SHACK! Grab the Yellow Pages and find a real electronics store.

 

I found one but they were currently out. It was kind of a general knowledge question.

To further it, is it basically about the Farad's being the same? Is the voltage stated on the capacitor the max it should see?

I actually haven't fixed anything. I've managed to take it apart. Which, as with anything, is the easy part. I've never soldered anything past about 10 wires in my life... so... here's to jumping in head first.

I bought my soldering iron about 2 months ago and my de-soldering iron about 1 week ago.

Here's my thread about my "progress" so far: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/warning-cluster-teardown-corrosion-other-issues-w-pics-614646/

 

The only measurement you are concerned about matching is the capacity (ie. the uFarads). Even that is not very critical since 9x out of 10, larger value electrolytic capacitors are just used for filters and standard capacitors have a 20% tolerance value. So you could put anything around 47uF in there and likely not have issues. Hell, you could probably stuff 330uF part in there and still not experience problems but since I don't have the schematic handy I can't say for sure.

The voltage measurement is simply the maximum safe working voltage of that capacitor, so anything over 16V is fine for automotive use 99% of the time. Note that you don't want to get into higher voltage parts because the physical size of the capacitor and it's leads starts to get fairly large. Also running a HV cap at lower voltages all the time will reduce it's life...So the 50V unit is fine. I almost alway use 50V capacitors in all applications unless they call for a really low voltage (6.3V) or a much higher voltage.

 

50V is fine.
Remember, this is a maximum rated voltage the cap can handle.
If you overvoltage the cap max rating, that thing will pop.
Keep it under the max, and the cap will stay happy.

As others have said, just as long as the farad rating is the same, everything should be cool.


-Ted

 

You could probably get it free if you when to a local college. anyway I may have one I could send you.. let me look through my stuff.

Edit: sorry I could only finda bunch of 6.3 volt ones. Keeping broken DVD players and **** helps when you need to repair other broken electronics. Though I never really have fixied anything it was a phase I went through.

Edit again: Oh yeah, Radio shack over prices their stuff by a ridiculous ammount What's a .05 cent cap they'll sell for 2 bucks.

 

How could I get it free if I went to a local college (I go to UT...)?

I'm going to get one from Shields Electronics (they have on in Bristol too). It will probably be about .05 or something. It's good to know I could use a different (higher) voltage though.

 

Uh, I got stacks of 47u @ 35 volt I will send you for the price of a stamp (I work in a electronics repair facility..).

 

If I can't find one today I might take you up on that. I need some more stuff anyways so I was already having to go to the electronics store.

 

Whatever works for you man! Just let me know.

Rat

 

Since I'm asking about interchangeability... might as well keep asking.

Are radial and axial capacitors interchangeable?

 

Radial vs. axial just refers to mounting. Radial capacitors are the tall ones (what you are replacing). Axial capacitors are "horizontal" in that one lead exits from each side.

You can probably use either in this application since the radial will fit exactly how the old one did, and an axial capacitor can be mounted with one lead through the original hole and then the lead at the other side bent to run along the body and underneath to the other hole.

 

Ok, thanks for confirming that. That's pretty much what I figured, just wasn't 100% sure.

 

Make sure you put it back the same way you toke it out, electrolytic caps are polar.

 

Just to be a jerk (a bit too technical), operating electrolytic capacitors way below their rated voltage tends to lower the voltage limit of the capacitor. Also, ESR is voltage dependent on those things - the impedance changes with voltage - so if that's a cap used at some frequency, changing the voltage rating might change the output.

None of the things I just brought up should come into play here though, unless you get a cap way above the original voltage rating!

 

Thats exactly what I was thinking. I am finishing up an electronics techinician degree and we have caps laying around of damn near any value up at school.

Also, My5ABaby, I didn't know you went to UT. Is it UT Austin? If so, we gotta meet up sometime. I live about an hour away in Killeen, but come down to Austin periodically. Once I get my car running (hopefully in the next week or two) I'm gonna try to get do to the TexasRX's meetings.

 

Ut is Uni of Tennessee. And I don't know if you could get it for free or not from a college but the professor at my local community college (Walters State) just gave me a few things once.

 

No problem...
More technical is always appreciated.
I've never touched this stuff since freshman year in college! :P


-Ted

 

No jerkiness there, more info's always good. However, you lost me after about the first sentence . From what I gather, just don't use a 309483v 47uF capacitor. Check...

Uhhhhhhhhh, how do I tell. It kind of fell of so I didn't really measure (or whatever you would call it).

University of Tennessee.


Anyways, I went to the electronics store (only one I know of in town...) and they wanted ~$1.50 for one or ~$5 for a pack of 15 or so.

So, my options are, using a random example:
A) Pay $8 for a steak dinner and get 1 steak. (local)
or...
B) Pay $1 for a steak buffet and get 10 steaks. (J-Rat)

J-Rat now has a pm in his inbox.

 

and if youre bored, try running a cap with too much voltage, it will put on quite a show with lots of interesting noises lol

 

Huh?

 

It will blow up if you overvoltage it or connect it backwards (with a high enough voltage).

 

and STINK too.