Capacitor marking

S

siyom

Member

• Apr 28, 2013

• #1

So i have this 640uF capacitor and its the last one,it's not properly marked or atleast its not marked according to what i'm used tne lead is shorter than the other and there's a band around the position of that lead.
I know it sounds like a stupid question but always confuse these things and i end up blowing caps this time its my only one and i dont wanna blow it,so how do i connect it?
1) long lead to Vcc short lead to ground
2) short lead to Vcc long lead to ground

Ashamed

 

audioguru

Well-Known Member

Most Helpful Member

• Apr 28, 2013

• #2

Simply look in Google Images like I did.
Modern capacitors have a minus sign and arrow on the side of the negative wire. It looks like the negative wire is the short one.

 

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N

Norator

New Member

• Apr 28, 2013

• #3

Connecting it to a 9v battery through a 10K or 100K resistor and monitoring the cap voltage after a few seconds may tell you the correct polarity with almost zero risk of damage.

 

D

DragonForce

New Member

• Apr 28, 2013

• #4

The negative lead will give continuity with the aluminium case

 

BeerBelly

Member

• Apr 28, 2013

• #5

Long lead Pos.......
Short lead Neg.......

Same as LEDs

 

pfofit

Active Member

• Apr 30, 2013

• #6

DragonForce said:

The negative lead will give continuity with the aluminium case

Click to expand...

Not always.

 

D

DragonForce

New Member

• Apr 30, 2013

• #7

Deleted

 

Last edited: Apr 30, 2013

Mr RB

Well-Known Member

• May 1, 2013

• #8

pfofit said:

Not always.

Click to expand...

Or never.

The aluminium cases are coated with epoxy paint on the inside to make sure they do not conduct in any way with the inner workings of the cap.

 

DerStrom8

Super Moderator

• May 1, 2013

• #9

Long lead +, short lead -. Just as beerbelly said.

Also, as AG mentioned, it should have a "-" sign on the negative side of the capacitor case.

Matt

 

Last edited: May 1, 2013