Assorted capacitorsAn electrical device which electricity can flow into, but not through. This makes it suitable for briefly storing electrical charge. There are many uses for capacitors in automotive electrical circuits.

For example, ever notice how the interior lamp in your car does not go out the minute you close the door? And when it does eventually go out, the lamp dims down to nothing, rather than suddenly extinguish? This is a capacitor at work.
Capacitors are also useful for suppression to avoid sound interferance on radios, or can be used in time delay circuits, such as those used to control glow plug circuits.

The picture here shows a variety of capacitors. The first three on the left are ceramic capacitors and the two on the right of the picture are electrolytic capacitors.

Symbols for a capacitorThe symbols shown here are for a non-polarised capacitor on the left and a polarised capacitor on the right.

During your time on Phase 2, you will come across electrolytic capacitors during your studies of basic electronics and time delay circuits.

Note: if a capacitor is polarised, it must be connected correctly into a circuit, otherwise damage to the capacitor and/or the circuit will result. Capacitors can only store  DC electricity, they cannot conduct it. AC passes through capacitors as though they weren't there.

Capacitors will have markings to indicate how much energy they can store as well as the maximum voltage they can be exposed to. NEVER EXCEED THIS VOLTAGE.

When replacing a capacitor, use one rated at the same (or higher) voltage.

Capacitors on YouTube:

Ultra Capacitors

» Course Glossary


Please note, if you want to contact the main Training Centre in Baldoyle, you need to ring 01-8167400.

If you want to contact the CP Fitters' Section, you can Contact Us by email, admin@cpfitters.info, or by telephone: 00 353 1 8167543 This number gets you through to the CP Fitters' Section, Baldoyle Satellite Unit.

Our Address is : Construction Plant Fitters' Section, Unit 116, Grange Way, Baldoyle Industrial Estate, Baldoyle, Dublin D13 CA48.
We operate in a satellite unit which is about 300 metres away from the main training centre. You can see the location of this unit here, in Google Maps. You can also Check here for directions to the Baldoyle Training Centre.

Find Us on Find us on YoutubeFollow cpfitters on Twitter

Is Féidir Linn! You can view all the menus on this site as Gaeilge by going to the homepage, top right hand corner, and dropping down the language selection menu. By default it reads English (en), so just select Gaeilge (ge) instead.