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Inductive voltage and signal transfer

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Eric Larson

Jan 1, 1970
0
I am looking for information on creating a 12 to 24V power/signal source
that will cross a small air gap (10 - 15mm).

Thanks.

Eric
 
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default

Jan 1, 1970
0
I am looking for information on creating a 12 to 24V power/signal source
that will cross a small air gap (10 - 15mm).

Thanks.

Eric
Have you tried Google for it? There's lots of information on creating
high voltages from low sources. Lots of circuits for driving auto
ignition coils

One assumes 10-15 cm requires 10+ KV unless your working in some
atmosphere other than air at sea level. Electrode shape will affect
the distance as well.
 
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default

Jan 1, 1970
0

Oh, that's a horse of a different color.

Are you intent on getting information / data across the divide or
power, or both?

Say you had a 4-20 ma industrial control sensor that had to transmit
info to the other side of a sealed glass block. You might put a cup
core on both sides of the glass, excite the one outside the glass with
a square wave. It's opposite number is on the inside of the chamber
and connected to a sensor. The 4-20 sensor is connected to the full
wave rectified and filtered cup core coil on it's side of the glass.
As long as the gap remains constant that might be all you'd need . . .
measure the current used by the square wave driver and massage it to
replicate the 4-20.

You mention a voltage level. Power across the divide . . . That is
usually done using two halves of a ferrite cup-core and a high
frequency drive square wave. The distance is critical to both the
voltage and current in that scheme so if the distance will vary the
power transfer efficiency will vary too.

Basically just a transformer with a gap in the magnetic circuit.
Bigger cores work better over larger gaps.

They use something like that on a prototype electric car - the coil
with pole pieces is excited at a high frequency and slipped into an
opening in the body of the vehicle that contains a pair of cup cores
with windings that pick up the AC signal and use it to charge the
batteries (a consumer safe way to transmit power in any environmental
condition)
 
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Eric Larson

Jan 1, 1970
0
Thanks for your comments.

Seeing as I am not a full fledged EE I was hoping to find a schematic or
tutorial with an example of this sort of device that I could use as a spring
board. I could spent months trying to figure out the math involved on my
own. I want to communicate and transfer power across an air gap less than a
half inch. I would like to keep the size of the inductors down to at least
1" in diameter. The power transfer would be to change either a capacitor
array or a battery. I'm looking for a device powered in the 12V to 24V range
for now.
 
D

default

Jan 1, 1970
0
eeing as I am not a full fledged EE I was hoping to find a schematic or
tutorial with an example of this sort of device that I could use as a spring
board. I could spent months trying to figure out the math involved on my
own. I want to communicate and transfer power across an air gap less than a
half inch. I would like to keep the size of the inductors down to at least
1" in diameter. The power transfer would be to change either a capacitor
array or a battery. I'm looking for a device powered in the 12V to 24V range
for now.


Damn, thought I posted a rely days ago

There's no way that I know of that you can do what you want. A small
gap in a magnetic circuit is a big change in energy transfer. The
magnetic field decreases with the QUBE of the distance.

Want enough energy to charge a battery across 1/2" with a one inch
core and it may take a kilowatt or two to get a fraction of a watt
out.

Likewise capacitance transfer won't work - even assuming your space is
a good dielectric.

That leaves radiation - light, IR, microwave etc. - assuming the space
between the transmitter and receiver can pass the energy.

Sound energy?

Post what you are trying to do maybe there's another way.

There is a design for a auto battery charger . . . a coil / core with
a diameter of about 5" is excited with a high frequency and is slipped
into a notch to charge the vehicle. Inside the vehicle are a pair of
coils and cores that are on opposite sides of the exciter coil. They
use a 5" coil/core with a high frequency power driver to transfer
energy across a 1/8" space on either side of the coil.
 
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