> From:
> Victor Tikhonov <[EMAIL PROTECTED]>
> 5:55 PM
>
> Subject:
> Re: Sparrow Ammeter
> To:
> [EMAIL PROTECTED]
>
>
>
> John Lussmyer wrote:
> >
> > At 05:26 PM 10/9/2002 -0700, Victor Tikhonov stated:
> > >If you draw PWM 200A pulses 50% duty cycle (like
> > >200A-0A-200A-0A every 100us or so), the average current
> > >is 200*0.5=100A but your analog movement meter may show 60...70A.
> >
> > Is there any kind of simple circuit I could add to the ammeter to make it
> > useful?
>
> No need. Just re-calibrate it and draw new scale on it. It won't be
> too accurate, but will be far better than it is now.
>
> If you want to fix the situation electronically, the circuit should
> average independently of the wave form. I wouldn't bother, because
> it's not used to drive other instruments, it's only to give you an
> idea about how much you're consuming. Calibrate it with borrowed
> good true RMS am-meter in series with yours, and you can get 5%
> accuracy - enough for visual judgment.
>
> Victor
Can one assume that the emeter is reasonably accurate? If so, another
solution is to install the rs232 model and get a old serial palm from
ebay and run EVdash.
If it's not accurate ... well that's unfortunate :>
--
Keith H. Bierman [EMAIL PROTECTED]| 650-352-4432 voice+fax
Sun Microsystems Laboratories | sun internal 68207
15 Network Circle UMPK 15-224 |
Menlo Park, California 94025 | [EMAIL PROTECTED]
<speaking for myself, not Sun*> Copyright 2002
