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Old 10-08-2012, 04:39 PM
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radiotvnut radiotvnut is offline
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The 1uf/50V, the 10uf/25V, and the 470uf/500V are very likely to be electrolytic capacitors and if that's the case; then, yes, they are polarized and the new capacitors will need to be installed correctly or you will likely experience some unwanted excitement.

There should be markings on the old electrolytic capacitors that indicate which terminal is negative (-) and which is positive (+). The new capacitors will have to be installed with the same polarity as the old ones.

The newer electrolytic capacitors usually have the negative terminal indicated by an arrow with a "-" symbol inside the arrow.

In most cases, anything under 1 uf will be a non-polarized, non-electrolytic cap and it won't matter which way the cap is oriented in the circuit.

There are exceptions; but, most caps that are 1 uf and above will be the polarized electrolytic type and they must be wired in correctly.

Often, a new capacitor won't quite match the value of the old cap. It's hard to find modern day 50 uf capacitors; but, a modern 47 uf cap will work just fine in it's place. Same goes for using a 33 uf in place of an old 30 uf and using a modern .047 uf in place of a .05 uf, etc.

It is perfectly OK to use a replacement capacitor with a voltage rating that's higher than the original capacitor; but, it is never OK to use a replacement capacitor with a voltage rating that's lower than the voltage rating of the original capacitor. For example, you can use a 630V cap to replace one that is rated at 100V, 200V, or 400V. However, it's not OK to use a 630V cap to replace one that was rated at 1KV and it's not OK to use a 450V cap to replace one that is rated at 500V.
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