Black = negative Cap

Calebay · 9th August 2005, 12:58 PM

Hello

i have 4 older caps 22000uf 80V from a sony ES power amp

but i have no idear what is + and -

Black= negative or is it the other way araund? see pic if that help

Tnx

peranders · 9th August 2005, 01:01 PM

Do you have any text printed on the can?

Calebay · 9th August 2005, 01:10 PM

this is all it says

peranders · 9th August 2005, 01:38 PM

Take a DVM and measure the resistance between the terminals and case. Normal negative is more or less connected to case.

Calebay · 9th August 2005, 02:27 PM

im not able to measure anything infinity resistance

anything else i can try before i connect my 450VA trafos?

janneman · 9th August 2005, 02:42 PM

Try it with a 12V trafo through a resistor of say 100 ohms first to see if the caps are connected correctly. If not, you will see a very large current resulting in low voltage at the caps. Can you measure voltage? And oh, btw, you didn't mention the rectifiers, but you have those too?

Jan Didden.

Calebay · 9th August 2005, 03:26 PM

okay ill try that first yes i have a multi meter i did try to measure the but it seems like the non of the terminals have any connection to the case at all..

don't worry i have rectifiers in there as well

i have build an amp before

Calebay · 9th August 2005, 04:06 PM

okay i did this test using a 9v batt instead i connected my multimeter in serie whit the batt. to measure the current

when i connect it to the cap the same this happens no matter if its + or - it draw a large amount of current the first few seconds, then drop to zero. seems normal..

i also try to measure the voltage over the cap after its been charged. its drop for 9 volt slowly. the same speed + and -

Peter Daniel · 9th August 2005, 04:11 PM

Maybe this helps:

Netlist · 9th August 2005, 04:13 PM

Somewhere on the board there's a clever post how to measure polarity with a scope, looking at dropping waveforms. I can't however remember who posted it, when and where.

/Hugo

9th August 2005, 01:01 PM	#2
peranders Electrons are yellow and more is better! diyAudio Member Join Date: Apr 2002 Location: Göteborg, Sweden Blog Entries: 4	Do you have any text printed on the can? __________________ /Per-Anders (my first name) or P-A as my friends call me

9th August 2005, 01:38 PM	#4
peranders Electrons are yellow and more is better! diyAudio Member Join Date: Apr 2002 Location: Göteborg, Sweden Blog Entries: 4	Take a DVM and measure the resistance between the terminals and case. Normal negative is more or less connected to case. __________________ /Per-Anders (my first name) or P-A as my friends call me

9th August 2005, 02:42 PM	#6
janneman diyAudio Member Join Date: May 2002 Location: Where Germany, The Netherlands and Belgium meet Blog Entries: 6	Try it with a 12V trafo through a resistor of say 100 ohms first to see if the caps are connected correctly. If not, you will see a very large current resulting in low voltage at the caps. Can you measure voltage? And oh, btw, you didn't mention the rectifiers, but you have those too? Jan Didden. __________________ /New Linear Audio publication: Baxandall & Self on Audio Power!

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9th August 2005, 02:27 PM	#5
Calebay diyAudio Member Join Date: Jul 2003 Location: Denmark	im not able to measure anything infinity resistance anything else i can try before i connect my 450VA trafos?

9th August 2005, 03:26 PM	#7
Calebay diyAudio Member Join Date: Jul 2003 Location: Denmark	okay ill try that first yes i have a multi meter i did try to measure the but it seems like the non of the terminals have any connection to the case at all.. don't worry i have rectifiers in there as well i have build an amp before

9th August 2005, 04:06 PM	#8
Calebay diyAudio Member Join Date: Jul 2003 Location: Denmark	okay i did this test using a 9v batt instead i connected my multimeter in serie whit the batt. to measure the current when i connect it to the cap the same this happens no matter if its + or - it draw a large amount of current the first few seconds, then drop to zero. seems normal.. i also try to measure the voltage over the cap after its been charged. its drop for 9 volt slowly. the same speed + and -

9th August 2005, 04:13 PM	#10
Netlist diyAudio Moderator Join Date: Jan 2003	Somewhere on the board there's a clever post how to measure polarity with a scope, looking at dropping waveforms. I can't however remember who posted it, when and where. /Hugo

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