On 9/23/19 3:11 PM, Ralph Mowery wrote:
In article , elson@pico-
systems.com says...

Without a Wattmeter, you have no idea what the actual power draw is.
Some of that 2.3 A is reactive current, at 90 degrees to the voltage, and
you are not billed for that. Measuring the current and voltage
separately, you only get the VA (volts * amps) which is NOT the power in
Watts


I never could get it in my head about AC power either. I know how volts
or amps can lead if there is any reactance in the circuit. I have an
inline power meter that shows voltage, current, and power (watts )_ A
heater element will show about the same watts as the voltage times the
courrent. A load with a large transformer in it will show a much
differant V times A than the watt meter. I understand it doing that,
but not how the power company realy charges for the power.


I did all of these AC calculations, but it was at least 20 years ago.
I've mainly worked with DC since that time & I've always found DC a lot
simpler. Speaking of which, I understand there's actually a way to run
these MV bulbs from DC. I wonder if it's like is done with certain
x-ray tubes and just using a diode to convert to DC, or more elaborate?