More Power from a AC coil
More Power from a AC coil
(OP)
I have a AC coil that I'm trying to get more stroke out of, any suggestions...I cannot add any diodes or rectifier circuits. I was hoping that I could add more windings? or something that I could do to make a new coil. Any help would be great.






RE: More Power from a AC coil
You can often get good results by having a PTC thermistor and a resistor in series with the coil. Or a simple timed switch that shorts the resistor and opens after about 100 milliseconds. There are many possibilities.
If you can think of adding a rectifier and a capacitor, you can get very efficient coils. Just design it so that the capacitor applies two or four times more voltage than the coil was designed for. That will pull it in quickly and with great force. The capacitor shall be chosen so that it has been discharged down to nominal voltage after the core has pulled in. A series resistor then reduces current to holding current.
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: More Power from a AC coil
RE: More Power from a AC coil
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: More Power from a AC coil
RE: More Power from a AC coil
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: More Power from a AC coil
RE: More Power from a AC coil
I see the dilemma. Rewind the coil. Use a wire with about ten times that area and wind as much wire there is room for. That's the simple solution. You may need to do a few tests before getting it right.
There are mathematical formulae for this. But let's KISS.
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: More Power from a AC coil
Do you mean a wire of size of .33" diameter? That is a big wire, I may can get a few turns, if I can find this wire size and fit it on the nylon bobbin.
RE: More Power from a AC coil
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: More Power from a AC coil
3x the diameter per turn
10x the area per turn
1/10 the turns
1/100 the impedance (I am assuming the impedance is primarily inductive, NOT resistive, which gives inductance proportional to turns squared)
1/10 the voltage
I = V/Z = (1/10)/(1/100) = 10 times the current (assuming your power supply doesn't droop under the heavier current).
Phi = L*I/N = 0.001 * 10 /0.1 = 1. Should roughly recreate the same flux and force.
Check of Current density:
Current / area per turn = 10 / 10 =1. Should create roughly the same I^2*R heating.
You mentioned you are exploring the mechanical aspects. Also the magnetic aspects deserve consideration. In some cases halving an airgap is equivalent to doubling the current.
There are I'm sure quite a few considerations for a successful design. Like for instance does it drop out when you want it.
I would mention that there are people who know a helluva lot more than me that design coils and put a ton of thought into it. A lot of them hang out in the magnetic forum.
If it were me, I would be looking for an off-the-shelf relay to meet my needs. Why reinvent the wheel?
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RE: More Power from a AC coil
Phi = L*I/N = 0.01 * 10 /0.1 = 1.
(stop laughing, you knew what I meant)
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Eng-tips forums: The best place on the web for engineering discussions.
RE: More Power from a AC coil
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Eng-tips forums: The best place on the web for engineering discussions.
RE: More Power from a AC coil
"In some cases halving an airgap is equivalent to doubling the current."
should have been:
"In some cases halving an airgap is gives twice the force per current drawn."
The effect of decreasing airgap can be to decrease current draw, but if you don't change volts/turn you don't change flux.
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Eng-tips forums: The best place on the web for engineering discussions.
RE: More Power from a AC coil
RE: More Power from a AC coil
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com