Author Topic: Meter readings (mA,V)  (Read 1718 times)

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Offline gregfox151@gmail.com

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Meter readings (mA,V)
« on: March 17, 2013, 05:59:36 pm »
Hi,
I have a panel meter that reads in volts, from 00.01 up to 30 volts.
I also have a circuit I want to connect it to, that puts out 0-199 mV.
When I connect to the circuit and try to read say, 140mV, my meter reads 00.01.
Is there any way (other the easy way out, of simply getting a meter that reads in mV) for me to be able to read the 140 mV more precisely?
I thought of an H bridge or something along those lines, but ahhh, the must be an easier way.
Any thoughts appreciated.
 

Online Simon

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Re: Meter readings (mA,V)
« Reply #1 on: March 17, 2013, 06:38:51 pm »
you need to find out how to alter the meters settings, or it has one scale only and your stuffed
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Offline toster

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Re: Meter readings (mA,V)
« Reply #2 on: March 17, 2013, 06:42:10 pm »
wouldn't an op-amp do?
 

Offline gregfox151@gmail.com

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Re: Meter readings (mA,V)
« Reply #3 on: March 17, 2013, 06:43:48 pm »
op amp? how would you use it?
 

Online Simon

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Re: Meter readings (mA,V)
« Reply #4 on: March 17, 2013, 06:44:40 pm »
not really as the meter reads on a certain scale, amplifying the value will just  mean that the scale will be all out and you've changes the meter, say he does a x10 on it that means it now only good to 3V and misreads everything
https://www.simonselectronics.co.uk/shop
Varied stock of test instruments and components including EEVblog gear and Wurth Elektronik Books.
Also, if you want to get ripped off: https://www.ebay.co.uk/usr/simons_electronics?_trksid=p2047675.l2559
 

Offline qno

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Re: Meter readings (mA,V)
« Reply #5 on: March 17, 2013, 08:05:41 pm »
usually these meters have a full scale of 320 mV or 400 mV.
With a voltage divider and a variable decimal point you can expand the range.

Check for a part of type number.
Google for data. Usually the manufacturer wants to sell as much as possible by showing how easy it is to use the part in the datasheet.

You have to change the input voltage divider and change the position of the decimal point.
Why spend money I don't have on things I don't need to impress people I don't like?
 


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