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
