4000uf50v capacitor replacement 4700uf50v?

Zinfer

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I can't seem to find any 4000uf50v axial caps. However there are 4700uf50v axials available. This is the large cap on an old Death Race pcb. Would this be a good replacement for it?
I'm thinking it's fine, but wanted a second opinion. This electrolytic is older than dirt and is probably pretty well dried out.
 
if anything itl filter current better .on power supply or power filtration caps u can go bigger on your farads and voltage. but normally use the same farrad rating if u can and u can increase voltage. because the voltage rating just says how much the cap can handle, higher voltage rating the longer it lasts.
 
because the voltage rating just says how much the cap can handle, higher voltage rating the longer it lasts.

Not true!

Electrolytic Caps are rated for a Working voltage. You should run them at 20% under the rated voltage - when running new designs. IF you replacing caps in an existing design.. be at LEAST as good as the original part.

Running a 500V cap at 50V is a waste of cash and does NOT prolong it's life:

"Among these factors, temperature (ambient temperature and internal heating due to ripple current) is the most critical to the life of aluminum electrolytic capacitors.

Voltage within the allowed operating range has little effect on the actual life expectancy of a capacitor. However in certain applications or misapplications, the applied voltage can be detrimental to the life of an aluminum electrolytic capacitor.

When in service at voltages equal to or below the rated value, the life of electrolytic capacitors is affected less by applied voltage than by operating temperature. [...] The curves show that the life of the capacitor has not been significantly increased by a reduction in voltage. "

http://www.chemi-con.com/u7002/life_ms.php

The best thing to do is spend the cash on higher temp rated caps... IE longer times at 120C instead of the cheaper low life at 80C.

For example; If I was designing a new Powersupply with a 5VDC input... I'd run the next higher voltage grade. usually 6.3V or worst case 10/16V. IF I know the caps going to be in a hot monitor or some other non-airflow enviorment... I'd get 120/150C rated caps with as long hours as I could.
 
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Ok, I ordered the 4700uf50v cap to replace the 4000uf50v. Thanks for the input.
 
Reminder: THIS ONLY APPLIES TO POWER SUPPLY FILTER CAPS. You can always use a higher rated voltage. But in tuned circuits and coupling circuits it's pretty critical to keep it identical.
 
I agree. I'd never normally want to do anything like this but apparently a 4000uf50v axial isn't even manufactured any longer.
 
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