Saturated Inductor Current Increaser

[antijon]

Hey everyone, I'd like to start a new topic.

I have just done some experiments with inductors and magnets, and I'd like to know if anyone has any experience.

My initial thought was based on observations of Lenz's law in inductors.
If we take an inductor and apply a magnetic field, the inductor will produce a current whose magnetic field opposes the initiating magnetic field. Now, if the external magnetic field is static, no current will be induced, however, we know that the inductor will be more biased towards positive or negative current, which can be seen with magnetic amplifiers.

Now, if we take a large inductor with a saturating, external static field, and we apply a current, Lenz's law says that a current will produced to oppose the applied current. However, the applied current, if alternating, will either try to increase, or decrease, the externally applied magnetic field. Because the field is saturating, the effect will be induced immediately upon the entire coil. Also, this induced current will be very near the applied voltage. So if I have a very large inductor, and I apply 120V at low current, the inductor will immediately produce an opposing current near 120V, but with the entire current of the inductor. Therefore, larger inductor, larger magnets, equates to larger currents matching incoming voltage.

Okay, in some brief tests with a small inductor- I'm using a small transformer with the upper I block removed, and two MOT, err, magnetron magnets on the top and bottom. Also have a weight on top to prevent the magnets from vibrating.

My voltage was line supply, 120V fed through a 5mfd capacitor to limit current. At 60 HZ, the capacitor has a reactance equal to 530 ohms, which gives me a total power input of ~27watts. In the schematic you see I have the capacitor feeding the inductor, which is in parallel with the load. My load was a light bulb that measured 35 Ohms when hot. Now, without the load the open circuit voltage was 150V. With the load attached, the voltage read 50V, and the bulb was dimly lit. Now, I really don't know this stuff that well, but if this is correct, that 50V across a 35 Ohm resistance equals 71 Watts, yes? Or am I wrong? haha, please someone let me know.

Aside from current gain, the "saturated inductor" is also acting like some type of transformer. This may be resonance effects from the capacitor in line, but with a larger capacitor, 40mfd, the output voltage increased to 190V, and dropped to 150V across the load. But of course, this was too much power and my "little boy" inductor is now off-gassing.

So, anyone interested in trying this, or giving me your feedback? Thanks very much, everyone. ^^

[MarkE]

Power measurements:  You need to account for the reactance of the coil.  Reactance stores and returns energy.  It does not dissipate it.

When you bias the coil so that it can saturate in one direction, then you will not have nice clean sine waves.  You will need to integrate instantaneous power over the time interval of one cycle. That will give you the total energy across the cycle, and you can divide that value by the cycle time to obtain average power.

[antijon]

Great, thanks MarkE. I see what you mean about the dirty sine waves. Where i have 120V- 60V peak to peak- coming in, the biased coil may be outputting 150V to -30V peak to peak, or less.

So the increase in voltage could be due to the inductor storing energy, similar to a DC pulse on an inductor, where the crashing field creates a higher voltage, short-duration pulse, but the average istantaneous power remains the same.

Okay, thanks, I think you explaining it to me has helped me realize what I wanted to do with this.. although i need to read up more on inductor reactance.

Do you have any thoughts about the possibility of this working? For instance, I saw a patent before about pulsing an inductor and collecting the output with rectifiers, then using that for the input.

[forest]

Excuse me, I didn't understood. What is that circuit supposed to do ?

[antijon]

haha, that's okay Forest. The theory behind it was, well..
1. the large inductor blocks incoming AC current. This is like a typical low-pass filter that reduces current drawn from the line.
2. The static magnetic field was there to increase self-induction, and aid in blocking incoming AC.
3. Power is drawn from the circuit in parallel. This is because at high frequencies, the inductor is blocking incoming current by producing it's own opposing current. So the load sees, say if my supply is 1 volt at 1 amp, the load sees 1 volt, but 2 amps, 1 from the supply, and 1 from the inductor.
But in reality, it may not work this simply.