[SOLVED] Powering a DC circuit via induction via 220VAC

[Maverick001]

Hi All!

Electronics is something I studied at college, and that is such a long time ago that I will not profess to remembering anything.

I was wondering whether it would be possible to derive 12VDC (1 Ampere) from a 220VAC line through induction alone. I've often seen 220VAC wreak havoc with 1Vp-p (Co-axial video surveillance signal) through induction and was wondering whether windings in a coil in close proximity could be maximised to provide 12VAC which I could then smooth out and rectify.

Also, if this is at all possible are there any calculations that I can do around such a conundrum

Thanks in advance for any info.

Maverick001

 

[Audioguru]

Some products have induction chargers.

 

[Maverick001]

This of course is absolutely correct with the main difference that such chargers typically take AC in to provide inductive coupling output. I would like to inductively (non-contact) "parasitically" take power off my AC line to power something small.
Think of being able to take power for an LED illumination array off the power coming into my laptop while laying in bed. (I don't need to turn bedside lamps on and wake my wife)

 

[BradtheRad]

I once tried a similar method in an attempt to construct an led-On indicator to show when my refrigerator was running.

I could not find a convenient place to tap into the motor/compressor wiring. So I thought of a way to detect heavy current going to the unit.

I took a transformer, and wrapped a few turns of heavy wire around it. This wire carried current to the refrigerator. (It is essential to split the twin mains lead, so that the two wires together do not neutralize each other's AC magnetic field.)

There was no galvanic contact between the transformer and mains AC.

Then I attached an led across the windings. I tested different connections. I found there was one arrangement where the led lit dimly.

I am not sure if I created an inductive coupling, or a step-up or step-down transformer, or what.

 

[Maverick001]

Thanks BradtheRad, interesting point you make also, to use either live or neutral but not both. It makes sense :-D
Dim LED must mean 1.8V or thereabouts also and not the 5V~12V I was hoping to achieve. Could it simply be that you were experiencing a PWM type effect where your "light on/led forward bias" had a low (50%) duty cycle due to AC?
My search continues ����

 

[FvM]

If you supplement the speculative thoughts with a calculation of expectable field strength you'll realize that the idea can't work.

 

[Audioguru]

Maybe the products that use induction for their charger uses a high frequency.

 

[Jibby Benjamen]

Refer the below links

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[Audioguru]

HEE, hee. "The (high frequency) power is transferred a considerable distance. 3cm.

 

[microntechgro]

Refer the below links

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