Striped Capacitors

As I was going thru my stock of capacitors, it came to my attention a non-polarized capacitor having a black stripe at one end. A question came to my mind having new engineers and hobbyist in mind *"if they know what this stripe means and how to use it properly?"*

I would like to have some feedbacks from *newbies.*

The stripe on the end of some of the older capacitors such as the paper type and some polystyrene ones was to show on which end the outer foil is connected. This is designed to show which end of the capacitor (striped end) should be at the lowest AC potential which is quite often ground. In this way the capacitors were at least partially self shielding.

Hello Floy,
It will be of great help if you can please give a link of such capacitors or attached the picture of it.

You will have a good explanation.

Kindly do the needful.

There you go capacitor colour code
http://www.electronics-tutorials.ws/capacitor/cap_5.html

thanks Mark for the link

here's the pics

Wow! These are indeed the old paper capacitors! They would have to be about 50 years old or more! They were notoriously leaky (electrically) when they have been in service for many years. They would be good for historical projects or for a museum as they look new! The red capacitor is somewhat more modern and these do not leak like the old paper ones. Great stuff.

I'd like to add something here. Supposing you would like to use this kind of cap to a simple low pass filter, (knowing the characteristic of this cap), it's good practice that we connect the stripe side to ground to shield the signal from electratiscally coupled interference. But how about if your filter is a simple high pass filter, when neither side of the cap is grounded? Assuming that your circuit is of discrete parts or an opamp that would drive your filter it is assumed that the output of such is of low Z. Again it's good practice that we connect the stripe side to the low Z side, since it will be less susciptible to noise. Am attaching a sample circuit.