http://www.rfcafe.com/references/electrical.htm I am brushing up on my theory for some local exams. 25 years is a long time ! Some of those formulas are long forgotten. Anyone remember how to add up total "Z" vectors ??? I do now, but I had forgot. Audio/Video Doctor (formerly BEM) Keith Trumbla Winnipeg, MB Canada Phone. 204-832-6237 ----------------------------------------------------------------------------- This Email List is Public. Remove: http://www.tech-assist.org/remove.htm Lost Password: http://www.tech-assist.org and select "Login Problems?". Appliance Repair List: http://www.tech-assist.org/secure/tip/chatjoin.htm#app Email Archives: //www.freelists.org/archives/techassist/