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Topic: Arduino Uno R3 as miliVolt meter? (Read 2178 times) previous topic - next topic

jremington

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I used Current Transformer I have a full bridge rectifier circuit on its secondary side and the rectified current goes through a 560 Ohm resistor which yields about 4,5V with 1 kW load on the primary circuit
That won't work well. The diodes in the bridge rectifier have a voltage drop that depends logarithmically on the current passing through them. Normally, either the AC voltage across the resistor would be measured directly, or you would use a precision rectifier circuit to convert the AC to DC without the diode voltage drop. This post has an example circuit: http://forum.arduino.cc/index.php?topic=236085.0


Darkbound

They have 1V voltage drop I checked their datasheet, since the current at all times goes through 2 diods, that gives a total of 2V voltage drop. Not an issue:) but thanks for the warning!

jremington

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They have 1V voltage drop
No, they don't. For all diodes, the voltage drop is highly nonlinear and depends logarithmically on the current through them.

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