[Amps] What's wrong here- dropping resistor for DC meter?

Ron Youvan ka4inm at tampabay.rr.com
Sat Jul 9 05:37:48 PDT 2011


Ed Heimbach wrote:

>   Want to meter HV out. Power supply variable from 0 through 4.5 kv dc
>   Have 1 through 5 v DC movement.
>   I built dropping resistor string to multiply meter by 1000X.
>   Meter now has a non-linear response.
>   I.E., 1 volt position corresponds to 1000 volts, 3.25 volt on meter scale  equals 4.5kv.

> It would be nice if my max. volts (4.5 k) corresponded with the 4.5 mark on the scale card.

>   Easy way out would be to  jiggle resistor values to get mid point on scale (2.5 volts) to correspond with 2.5 kv, and then make new meter scale to agree with indicating needle.

>   Any better solutions?

   Put a 1 or 2 k Ohm resistor at the bottom of the bleeder string then put a 1 mA meter across it, 
re-calibrate the meter card for k Volts.
-- 
    Ron  KA4INM -   WARNING TO ALL PERSONNEL:
          Firings will continue until morale improves.


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