Bill Turner wrote:
On Tue, 19 Oct 2004 01:39:57 -0700, Roy Lewallen wrote:


Voltage and current, by themselves, don't do any heating.


__________________________________________________ _______

I don't follow you on this. Voltage can be present without any current,
but current can only flow if voltage is present, so what is meant by
"current by itself"?

--
Bill W6WRT

An electron beam in a vacuum can flow current without any voltage drop,
as can a superconductor. Granted, these are not everyday occurrences,
but they _do_ occur.

The real point that Roy is talking about is that whenever a voltage drop
occurs simultaneously with a current there is power being consumed --
and if it isn't coming out of the system as some other form of power
then it's being dissipated as heat.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com