What is different about the Hendershot and Aho builds that worked and all the builds that don't work? And what is not shown in all of the schematics?


The guess about the polarities in the above image was correct. I received a Russian magnetron and disassembled it. That's also why it is physically different from the one shown in the Hendershot build. Keep in mind the Lester Hendershot worked with the air force so he would have had access to radar magnetron magnets.

If the Hendershot does use the Wesley Gary "neutral zone" it isn't where we were thinking it is. We can look at the center of the armature as both the physical AND magnetic pivot point.







The other piece is opposite - South pole in the center and North poles on both ends.

I don't understand the analog part of the circuit well enough to explain how it works. Could we look at the "buzzer coils" (close to the magnet armature) as both a pickup and a feedback mechanism? Look at Figures 6 and 7 at the bottom of this page Understanding The Western Electric Double Coil Coin Relay
They are using electricity to drive the coils to one side or the other to drop the coin in one chute or another. It seems to me that if the analog part of the Hendershot circuit was set up to do the same thing but continually changing the direction of the current flow  through the buzzer coils (via the push-pull transformer configuration) it could also possibly harvest electricity from those same coils when the magnetic flux switches in the armature. But, as I said, I don't understand that part well enough to know if that is possible.

Anybody in contact with Mark Hendershot might want to pass this along. He did not use a radar magnetron magnet in his build. His build is the center, left picture in the top image.

Comments welcome.

nice investigative work! :)

~Russ

This makes perfect sense and no sense at all unless...

When an armature is placed in front of the poles of the radar magnetron magnet shown above the entire armature is magnetized to the pole on the ends because the center pole is indented and not in close proximity to the armature. So if the magnet is N in the center and S on both ends the entire armature facing the buzzer coils is S because the N field is contained inside armature/magnet volume by the boundary of the inside surface of the armature. That makes perfect sense.

It makes absolutely no sense, however,  if we think of the buzzer device, as a whole, as the source of the circuit oscillation. There is nothing to oscillate. Both buzzer coil cores are facing a south pole.

If, instead, we think of the buzzer device as a whole as the battery in a magnetic amplfier circuit, then there must be another source of oscillation. Since the cap/coil is a self contained RLC tank circuit (the R is in the winding) that is my candidate for the oscillator. Exactly opposite of what everyone thinks.

How would that work? I'm shaky on that but I'm thinking the current through the first buzzer coil wakes up Mr. Lenz and he kicks back into the other coil. Or, due to hysteresis, he kicks back into both coils.

So the magnet and armature are a magnetic battery and the cores in the buzzer coils are the terminals, so to speak. The coils around those cores supply both the stimulus and receive the Lenz response. That being the feedback mechanism I have been looking for in the circuit.

That is the important part of using the magnetron magnet - to get a single pole field in front of the buzzer coil cores to irritate the heck out of Mr. Lenz.

It would seemingly also answer some other questions.

Why are the buzzer coils attached to both the high voltage and low voltage sides of the circuit? To make one side weaker to receive the kick - bias.

Why don't the horseshoe magnet circuits work? They are presenting both magnetic poles to the armature so the Lenz response is wholly contained in the armature, effectively neutralizing the Lenz response to the buzzer coils.

Deleted due to link to bad site.

Another part of the Hendershot Generator that most people miss - a 2nd ringer coil armature that is not shown in the schematics.
Ringer Coils 2nd Armature PDF


Russ here,
EDIT'ED( can you have a direct link here as that link was full of spam/bad stuff)

thanks.