On Tuesday, January 12, 2016 at 10:46:12 PM UTC-5, Clare wrote:
On 13 Jan 2016 03:32:00 GMT, "DoN. Nichols"
wrote:

On 2016-01-13, wrote:
On Tuesday, January 12, 2016 at 8:28:47 PM UTC-5, DoN. Nichols wrote:


I did not know where to buy one, but I was able to find out how
to *make* one using neon lamps, resistors and capacitors, IIRC.


Enjoy,
DoN.

I was curious and searched the internet.

http://webspace.webring.com/people/g...se/3phase.html

You could use two 120 volt lamps in series for each 240 volt lamp. So
home free if you have a suitable capacitor.

Yes -- that is one version. I do see potential problems in
it, however:

================================================== ====================
You'll need 2 incandescent bulbs with a rated voltage equal to the line
voltage,

[ ... ]

Measure the ohmic resistance R of the bulbs. The condition to fulfill is
that the three reactances must be equal, so the reactive capacitance
should be:
================================================== ====================

The problem is that incandescent lamps have a resistance which
is quite low when cold (the condition under which you are measuring it),
and quite a bit higher when hot. (Easily an order of magnitude change
from cold to fully lit.)

But -- it may get you close enough for the thing to work.

You don't measure the resistance of the bulb. You calculate it
from the wattage and the voltage.

DMM's (digital meters) can measure the loads of light bulbs. Now, a digital oscilloscope is quite a leap from something like an analog oscilloscope (like the one I think rangerss was talking about). Digital oscilloscopes are more accurate in measurement than analog ones.