[Prev][Next][Index][Thread]

Current peak from MMC



One thing that kept me away from considering a MMC to start with, was an
(erroneus) gut feeling, that these small caps would be unable to deliver
enough current. So I tried to plug some data into Excell, and I thought
you might be interested in the results.

The cap of my choise is the Philips KP/MKP 375 series, which is a
polyprop. cap for high pulse applic. like deflection circuits in CRT
monitors. There are datasheets at www.philips-dot-com.  and that is where I
got the Dv/Dt values.

Assuming a 0,025 µF cap at 30 KV DC, and using the formula that Marco
posted recently, I came to these results:
(The first row is marco`s example, I included it to check if the formula
was entered correctly.)

Urdc	µF	dV/dT		amp./string	Amp. Tot.
				
	0,001	10000		10	
1000	0,022	5000		110		3750
1000	0,033	5000		165		3750
1000	0,047	3300		155		2475
1000	0,056	3300		185		2475
1000	0,068	3300		224		2475
1000	0,082	3300		271		2475
1000	0,1	3300		330		2475
1600	0,0047	5000		24		2344
1600	0,0068	5000		34		2344
1600	0,0082	5000		41		2344
1600	0,01	5000		50		2344
1600	0,015	5000		75		2344
1600	0,018	5000		90		2344
1600	0,022	3300		73		1547
1600	0,033	3300		109		1547
2000	0,0033	5000		17		1875
2000	0,0047	5000		24		1875
2000	0,0056	5000		28		1875
2000	0,0068	5000		34		1875
2000	0,0082	5000		41		1875
2000	0,01	5000		50		1875
2000	0,018	3300		59		1238
2000	0,022	3300		73		1238

This doesn`t seem so bad, and since a cap like this can be built for
something like 300 $, that is the route that I will follow.

Finn

            gtl-at-lists.uni-marburg.de