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2 volt module needs to read 100.0 with 1.000 volts input

Posted: Sat May 07, 2011 11:55 pm
by rickety_goodman
I have an EPM-8145B2V (2 volt 8145 digital panel meter).

I want it to read 100 (%) when a potentiometer delivers
10 volts to a resistor wired in series with the input.

How do I determine what (input) series resistor will
reduce the 10 volt input to an apparent 1 volt input?
(i.e., what is the input resistance of the module?)

How do I move the decimal point over 2 places to
the right so that 1.000 volts input will show as 100.0?

Thanks

Re: 2 volt module needs to read 100.0 with 1.000 volts input

Posted: Tue May 10, 2011 10:10 am
by rickety_goodman
I found some markings on the PC board saying that the 2volt
module has R2 = 100k and R3 = 11k.
If those are the input scaling resistors, then a 1Meg
resistor in series with the input would cause a 10.00 volt
signal applied to that resistor to display as 1.000 volts.

O.K.

Now, how do I move the decimal point over so that it
reads 100.0?

I see solder jumper pads D1 thru D4 and D1 is jumpered.
If I jumper D3 instead, will the decimal point move?
Also, what are the "F" and "H" jumper pads for?

Thanks

Re: 2 volt module needs to read 100.0 with 1.000 volts input

Posted: Tue May 10, 2011 10:22 am
by Tech_Marco
F = digital filtration (noise reduction). Ideal for used in an application if a lof of static or electro-magnetic field happen to have. Enable it will slow down the display though

H = Hold. I think you can guess what it is.

I'm sorry I don't know about the resistor things as the manufacturer really don't want people to play around with it.


Marco

Re: 2 volt module needs to read 100.0 with 1.000 volts input

Posted: Tue Mar 27, 2012 5:16 pm
by tonka1020
I am also looking for a similar answer, only mine is from 20.00v to 2.000v. If I change D5, it jumps to 200mV max..

thoughts?
T