Re: Wattmeters

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Dmitry (father dest)" <dest@xxxxxxxxxxx>

Hello Terry.

Tl> Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>

>>Terry - could you do a simple analysis of a little circuit in MicroSim
>>for the comparsion of our programs?
>>scheme - http://cis.ru/~dest/s1.GIF
>>V2 - sine wave 50hz, amplitude 220v, internal resistance - 0.01 ohm.
>>all diodes - MURS320, a cap doesn`t have inductance & resistance.
>>spectrum of current (V2) - http://cis.ru/~dest/s2.GIF

Tl> If the voltage is 220VAC then the amplitude is really 220 x SQRT(2)
Tl> so I think you need to put in 311 volts for the voltage source so the
Tl> RMS value is 220.

i`ve wrote "_amplitude_ 220v" - it`s just for example ;-)

Tl> But I did it with the same voltage you did.  You can just multiply
Tl> the numbers by SQRT(2)...

Tl> Here is the schematic:
Tl> The voltage and current:
Tl> Here is the spectrum over 1 second to get good resolution:

ok, thanx. i see results are almost identical with mine, but
switchercad doesn`t have those restrictions that spice student has, so
i`d keep using it for the time being :-)

Tl> The iron vane ammeter I got is good to 400Hz so it works just fine
Tl> even if the input current is nasty.

if the spectrum is so wide as here (220v rms, 2000uf, 500w):
http://cis.ru/~dest/s3.GIF
how could my ferrodynamic wattmeter (50 hz) determine the power so
exactly? maybe yours wattmeter can do the same or even the better?

if you have a "powerful" generator, you can connect the voltage
coil to the 220v (mains), and current coil could be connected in series
with the generator load. then set the load current at 2a and
changing the generator`s frequency determine when wattmeter`s
indication would start to decrease.
maybe the generator should be synchronized with the mains - you may do
it with a little step-down transformer. what about such experiment?
the logo is "find out how good is your wattmeter" ;-)

---
All I saw was a bright white flash, an explosion like a high-powered
gunshot, and the thick smell of ozone and electrical damage.
(c) Richard Quick  22-01-95 00:13:00