# measurement

Discussion in 'General Electronics Chat' started by Robert123, Mar 21, 2010.

1. ### Robert123 Thread Starter New Member

Feb 12, 2010
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measurement

Last edited: May 11, 2010
2. ### SgtWookie Expert

Jul 17, 2007
22,202
1,792
One easy way to measure current is to use a fixed resistance in series with the load, and measure the voltage across the fixed-value resistor.

Ohm's Law says:
E=IxR, or Voltage = Current time Resistance.
Similarily,
I=E/R, or Current = Voltage/Resistance.

So if you have a resistor that measures exactly 1 Ohm, you can read the current flowing through the resistor by measuring the voltage drop across the resistor. In the case of a 1 Ohm resistor, 1V drop = 1A current.

You can scale the resistance down if desired. If you use a 0.1 Ohm resistor, then a 1 Volt drop = 10 Amperes current through the resistor.

PackratKing likes this.
3. ### Von Active Member

Oct 29, 2008
65
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A current transformer is another alternative.

It is a ring device and requires that the conductor pass throught the center.

No voltage drop or other issues with inserting a device in series.

Feb 4, 2005
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