17 votes

How to make a 1 H, 10 A inductor

Here's a 0.1H 10A inductor. It weighs 35lbs. There is a limit to the magnetic flux the magnetic core can handle. Above that it will saturate and inductance will decrease. Large value inductors require ...
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14 votes

How to make a 1 H, 10 A inductor

I think your only option to get a small footprint 1H, 10A inductor is to redefine the word "small" to mean "humongous." This is a 1H, 240mA inductor It is a box an inch and a half ...
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9 votes
Accepted

Measure inductance of air core inductor

In theory the inductance is proportional to the square of the number of turns, so 2x the turns would be 4x the inductance; however that only applies if all turns couple to all other turns. That doesn'...
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8 votes

How to make a 1 H, 10 A inductor

Cryogenic cooling and superconducting wire. A "small" footprint is indeed possible with this method. Beware the stray fields: flux density inside the coil will be many tesla, and even at a ...
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7 votes

Oscillating instrumentation amplifier with transformer coupled input

You are using the LT6230-10 opamp which is only guaranteed stable for closed loop gains of 10. At high frequencies the capacitative feedback you have will set a closed loop gain of much less than 10 ...
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5 votes
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Help identify schematic symbol

Perhaps it's a feedthrough capacitor. From the linked site, this image may approximate what you are seeing there: You can see the use of a wire through the center of a capacitor to illustrate that ...
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5 votes

Techniques for Compensating Inductor SRF

Put a 2nd lower value (and higher SRF) inductor in series with the 1st.
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5 votes

Techniques for Compensating Inductor SRF

As @jp314 said, series combinations can be used. Note that the smaller inductor will be series-resonant with Cp of the larger, so the common node between them may need damping (R+C across one, or to ...
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  • 5,126
4 votes

Techniques for Compensating Inductor SRF

If the filter is set to deliver a cut-off frequency of 100 kHz and the SRF of the inductor is 5 MHz, the ratio of the two frequencies is 50. This means that the parasitic capacitor associated with the ...
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3 votes

What is this ringing in the inductor current?

Ringing is not unusual in dc-dc converter circuits. Every inductor has some capacitance, and every capacitor has some inductance, and pair of conductors has both. The only way to definitely avoid ...
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3 votes
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Do power inductors having an aluminum winding (or a light weight winding) exist?

I'm not aware of aluminum being chosen for on-board inductors, but perhaps they are out there. The gains from pushing to higher frequencies, are far greater than the gains from using different ...
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3 votes

Purpose of stacked cores

I do not understand what is the purpose of the stacked core. Magnetics Inc (the company mentioned in the question) have got a great range of cores and, I have used several of them on jobs where a ...
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2 votes
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Purpose of stacked cores

Consider what each core experiences: For one core, you have N turns and I current, for N*I magnetization. And with \$l_e\$ and \$\mu_r\$ and all that, some inductance, flux, whatever... If you repeat ...
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2 votes
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What's causing MOSFET driver failure in my coilgun circuit?

So after much trial and error (and about 25 drivers blown up for testing), I've come to find a number of problems and their solutions. Thank you everyone for the comments, and I hope this helps ...
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2 votes

Voltage across the inductor

Intuitively, an inductor resists sudden changes in current by delivering sudden (and for an ideal inductor, arbitrarily large) changes in voltage. A capacitor is the complement: it resists sudden ...
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2 votes

Designing an RC snubber for AC solenoid lock (inductive load)

The most efficient solution would be to switch the coil with a triac. This handles turn-off gracefully, as the triac will keep conducting until current in the coil reaches zero. The same triac can ...
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2 votes
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Oscillating instrumentation amplifier with transformer coupled input

Be aware for wideband transformers. The output parasitic capacities can create a "spike" in AC analysis. Example: here for Cs = 2pF.
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2 votes

What is this ringing in the inductor current?

When the high side turns on (after the slow side turns off), the low side has been acting as a diode, and this diode has a stored charge (capacitance). Turning on the high side means it has to supply ...
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1 vote

Switching an active inductor controller with a high-side MOSFET

I am afraid, that you will be very disappointed about the result later, but if you want to give it a run, ok. You applied an AC voltage in the range of 100 V at the inductor tap. The AC current, that ...
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  • 3,572
1 vote

Voltage across the inductor

Find the steady-state conditions with the switch closed and open, then plug them into the differential equation for the switch-open condition. Namely at \$t=0\$ and \$t \rightarrow \infty\$.
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1 vote

DC-DC boost converter theory / principle / testing

Having spent all week tying to rebuild my burnt-out boost converter, the biggest problem I faced was heat in the MOSFET under any real load. After days of trying to make it work I found my problem to ...
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  • 145
1 vote

What do phase dots on an inductor mean?

In support of what Marc & Jose said, the inductor dot indicates where the wire starts to be rolled on the core. Because that dot point is below the rest of the windings, it is shielded by them. In ...
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