Was the meter linear to start with?
Did you check it with a variable DC supply and another meter?
How many resistors and what types are in the string?
What is theinternal resistance of the meter?
Also, your meter is interesting in that it has a 1 to 5 volt movement and
not a 0 to 5 volt.
73
bill wa4lav
________________________________________
From: amps-bounces@contesting.com [amps-bounces@contesting.com] On Behalf Of Ed
Heimbach [supermechanic18360@yahoo.com]
Sent: Saturday, July 09, 2011 8:06 AM
To: Amps@contesting.com
Subject: [Amps] What's wrong here- dropping resistor for DC meter?
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?
73 ab3ht
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