How to tell the positive and nagative pole?

[kuer]

Hi, bought 2 supercapacitors, see the pic, don't know which side is positive (Left or right)? Please help.

Thank you very much.

 

[rayma]

Hi, bought 2 supercapacitors, see the pic, don't know which side is positive (Left or right)?

Show us the left side, looks like the polarity marking is there.

 

[jkuetemann]

The black stripes to the left should indicate the negative pin, this is common practise for most types of electrolytic capacitors.

 

[rayma]

The black stripes to the left should indicate the negative pin, this is common practise for most types of electrolytic capacitors.

I've seen stripes like that with ++++++ in between, so let's wait and see the photo.

 

[kuer]

Pls, see the other side ( item in the pic is exactly the same as mine) , no more information, even on the top.

Thanks.

 

[CBS240]

no datasheet?

 

[DUG]

Or go to digikey and find a supercap datasheet.

 

[DUG]

And of course Tantalums have to be different.

 

[kuer]

Thank you very much everybody, So, I got wrong side.

This morning checked online, it is said the longer leg should be the positive, and the left side leg (with 2 stripes) on the pic is longer than the right. so totally wrong.

Now, do I need to switch +/- terminals? seems the tuner can store energy, not sure how long it is so far.

Thanks.

 

[rayma]

Or go to digikey and find a supercap datasheet.

According to the manufacturer, this is the right way, stripe negative.

 

[Ian Finch]

.... seems the tuner can store energy, not sure how long it is so far....

Supercapacitors are used like batteries. In tuners, they maintain the charge that stores station frequency data in CMOS memory. It was necessary back in the day, to use batteries or supercaps to hold this type of memory when power was off.

The memory time can vary according to the CMOS type and circuit leakages but 3 weeks was about the maximum time you could leave a tuner unpowered before a supercap memory died. Needless to say, they aren't intended for audio.

 

[kuer]

Supercapacitors are used like batteries. In tuners, they maintain the charge that stores station frequency data in CMOS memory. It was necessary back in the day, to use batteries or supercaps to hold this type of memory when power was off.

The memory time can vary according to the CMOS type and circuit leakages but 3 weeks was about the maximum time you could leave a tuner unpowered before a supercap memory died. Needless to say, they aren't intended for audio.

Thank you for your explaination.

Unluckily, after I replaced the old one, the new supercapacitor doesnot work as expected. Seems there is no difference with old one, not able to hold the momery over two or three hours after turning off.

I think the issue may be in other places.

 

[djk]

The stripe is on the lead connected to the case as well.