Why some Capacitor rating in milliampere 1

[vivekgupta999]

I have a one inverter circuit in which capacitor are rated like this, 0.25 Microfarad,1000V & 50 Milliampere. They are connected in parallel with thyristors. I am not able to understand why capacitor ampere rating is given? What its significant? Can I use 0.25microfarad & 1000V capacitor without bothering its milliampere rating? Pl. advice me.

 

[davidbeach]

Obviously you can do what ever you want, but you might not like the results. Generally ratings are there for a reason.

 

[melone]

Perhaps they are trying to imply the ESR rating for the device...

 

[Henneshoe]

The current rating is the amount of continuous current that can flow through the capacitor before it gets too hot and dies. Very important for AC signals. Not as important for DC.

 

[OperaHouse]

If you have a good capacitance meter it is fun to wander through a box of capacitors and measure the ESR. Pretty amazing how bad the internal resistance of them most are. As a general rule, stay away from anything polyester in pulse applications. They do make some polyester that are AC Rated, but these are generally for line operated equipment at 60 Hz. 50mA is pretty timid, must have a fairly large resistor in series.

 

[DHambley]

If the rating is in milliamperes, the ESR is an issue.
I have to disagree with "sty away from poyester" for pulse currents. You'll get the highest pulse ratings in polypropylene and polyester are a close second choice. Look at the AC ratings for AVX BN,FFB, FFV series or EPCOS MKT series. These have very high pulse ratings.

DH