Arlene, Simply put, the capacitor's function is to store electricity. The basic construction is two electrode plates facing each other, but separated by an insulator (dielectric). The capacitance is dictated by the area of the plates and the "strength" of the dielectric. The reason some capacitors have polarity and some do not is because different kinds of capacitors use different materials for the dielectric. Electrolytic capacitors use a very thin dielectric, so they are not as "strong". The trade off is that it can be packaged tightly it really tight and get a lot of capacitance in a small package. Other capacitors use a polyester film or mica as the dielectric, which is very strong, but also thicker, so you get less capacitance in a given package size. Kevin -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Cicchiani, Arlene M. Sent: Tuesday, October 24, 2006 2:37 PM To: [log in to unmask] Subject: [TN] capacitor polarity or not As a trainer, how would I explain to a manufacturer, in simple terms, the reason some capacitors have polarity, and some do not. --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------