Current detection

Tnbshr

Jan 10, 2015
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Jan 10, 2015
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Hi,
What I'm wanting to do is probably fairly simple but my background is not in the electrical/electronics field.
I want be able to detect current flow through a 16ga wire and turn on a LED when current is flowing.
As a mentioned I'm working with 16ga wire and will be connected to 110 volts running about 6 amps but would need to be safe up to 15 amps. The whole set up needs to be as small as possible! I know how I could make it work with a current donut but they are to big for this application, what else could I use to pull this off?
Thanks for the help
 

Bluejets

Oct 5, 2014
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As you have no background with electrical/electronics, best solution is an AC tong meter.(assuming your supply is 110V AC...you did not say...there are also DC tong meters available)


EDIT ..... Clamp-on meter in other countries
 
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(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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I'll presume that you're talking AC. The easiest solution is to place a toroidal core around the conductor and wrap some turns of wire around the torroid and then connect a LED (with an parallel diode (in anti-parallel) to the ends of this winding. This will create a current transformer where the current through your LED is proportional to the current in the conductor.

For this to work you MUST place the core around only a single wire. If you place it around a power cord that contains the active and neutral wires, the net current is zero, so your LED will never light up.

To do this requires that you access the insulated active (preferably) wire. This involves some risk. Make your turns of wire using fine, but insulated wire. To avoid having to cut the conductor, break the core in half, place your winding on one half, and reassemble it around the wire

There should be no direct connection between the mains conductor and your wiring (i.e. don't strip the mains wiring to see the copper!).

More turns will give you more current and therefore a brighter LED. For safety, ensure the LED and the diode are connected before applying power as the voltage can rise to a high value without a load.
 

Arouse1973

Adam
Dec 18, 2013
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Is this correct? I thought more turns will give more voltage and less current?

I think Steve means more turns of the live wire. This will drop the voltage and increase the available current.
Adam
 
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