Re: Wattmeters

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Steve Ward <steve.ward@xxxxxxxxx>

Hey Steve,

Well, since i got my boost converter working today, i can comment at
least on the kill-a-watt readings for my tiny DRSSTC.  The coil
usually drew about 400W when i had it cranked up, but the PF read
about .8-.85 usually with just using the old voltage doubler input.
With the boost converter, the PF is .99, and the power is still in the
400W area.  I can do a double check tomorrow, keeping everything
constant except the power supplies and compare PF and W between the 2
supplies.

I think i will also be testing my DRSSTC-1 on the new converter.  The
K-W should be happy at reading that power too... hopefully it is
indeed around 1200W like i expect it to be!

Sorry, i cant give up *my* meter... just too useful, but i do want to
see your results along with my own.

Steve

On 7/22/05, Tesla list <tesla@xxxxxxxxxx> wrote:
> Original poster: Steve Conner <steve@xxxxxxxxxxxx>
>
> Hi all,
>
> I just got hold of an old-style moving-coil wattmeter which I intend
> to use to measure my coils' power draw from the mains. It's totally
> electromechanical with air-cored coils- no electronics to overload or
> iron to saturate- so I expect it to read accurately even at high
> crest factors. I've got it hooked up right now and it says the PC I'm
> typing this on is burning 70w. I checked it against a true RMS DMM
> using a resistive load and it seems good within 5%.
>
> Does anyone want to donate me a Kill-A-Watt meter so I can compare
> the two on loads with high crest factor? I have a suspicion that the
> Kill-A-Watts clip when they are hit with loads that draw very high
> peak currents, which would make them read too low. DRSSTC power
> supplies draw extremely high peak currents and I'm wondering if this
> is why they look so efficient :-o
>
> Or has anyone else done similar tests (for instance, comparing a
> kill-a-watt against a more expensive electronic wattmeter that has an
> overload indicator)
>
> I would go out and buy a Kill-A-Watt, but they don't sell them over
> here in the UK. I can get other brands of electronic wattmeter but
> they're not the ones you all use ;)
>
> Steve Conner
>
>
>