Mr Lester J Hendershot's magnetic generator.

[thx1138]

CapCoil calculations

Different capacitance values have been quoted, but there is no way the 96" long by 2.75" wide element mentioned could have had a capacitance value as low as the 7.8nF.

Hence I decided to use a web based capacitance calculator -
Tesla Coils - Capacitance Calculator

An inner core 5.25" dia. gives a length of 16.5", by 2.75 inches high for width.
For Kraft paper and first insulation layer I have estimated a 5 thou plate spacing.
For dielectric constant I have estimated and entered 3.5.
When the number of platesis 2, and the dimensions are in inches,
the estimated capacitance of the first core-cap turn came out as 0.007139uF.

Clearly this is in the ballpark of 7.8nF, and PROVES that the centre core itself must have been circuit connected, for otherwise, and without its own tag connection, that figure would not even have been measureable.

I started on that document to compare the different documentation on the Hendershot device and immediately ran into discrepancies other than connections. The doc in the Mar-Apr 1989 JBR,Pg25 drawn in 1963 by Edward O'Brian RE the Aho build shows the inner can as 3" tall. Going by Fritz Lowenstein's work on capacitances, the smaller of the plates has the most affect upon capacitance. The second plate can be very much larger without adding even 1% to the capacitance value. The innermost cylinder must, by definition, be the smaller of the plates if it is connected. I used the calculator you linked to above with the parameters given but changed the 2.75" to 3" as stated in Edward O'Brian's work and the result was 0.007788uF. which would be 7.788nF. That's not to deny that the wrapped foils are 2.75" wide but the wrapped foils being so much longer means that they don't have as much affect on the capacitance as the innermost cylinder.

Now that I have most of my materials list together I found another reason to justify using 3" rather than 2.75". In all of the photos I've seen the inner cylinder extends above the coils somewhat and if you add up the number of turns of each coil and the thickness of the wire used in each coil there is no way that the L1, L2, and L3 coils would be less than 2.87" which would cpmpletely cover all of the inner cylinder if it were 2.75" and none of the photos show that. In fact they all show the inner cylinder extending above the uppermost coil.

I also found out that PVC was first used as wire insulation around 1950 so it seems I've been chasing my tail searching for the 0.100" O.D. wire. That 2.87" height above comes from using PVC jacketed 20 AWG solid with an O.D. of 0.066" for the top 2 coils at 12 turns each.

All of that also depends on the assumption there is indeed a connection to the inner cylinder since it would have to be the smaller plate of the capacitor part of the CapCoil.

I'm wondering how you came up with the dielectric constant of 3.5 and the 5.25" diameter in your calculation.

I also found notes in the From The Archives of Lester J. Hendershot document by Mark Hendershot that are hand written by Lester J. that say ".0078 MFD or posibly 1.3 MFD (see notes Orig.)" Emphasis added. Page 45 of the PDF document.

One other thing on the CapCoil: I don't think it said anywhere that the foils were taken from a Pyramid 80/40 cap. The statement was a Pyramid TM58, but that might just be the the part number for the 80/40 cap. I'm not sure.

I did find a Pyramid 40/10 cap and it is on its way. Its not for use in this project but it can give us the thickness of the foil and paper when I disassemble it. That brings me to another thought - the electrolyte in the old capacitors was basically a salt solution and failing to completely remove the electrolyte may be what led to the rusting of the coffee cans. It could have leached through the 3/4" inch gap in the shorter foils to the inner paper around the inner cylinder.

More to come on materials list.

In the mean time here's an article you may find interesting: Magnetic vortex oscillator driven by dc spin-polarized current

[GSM]

Great to see the thread has moved on without me. Will catch up soon.
I ended up as an unconcious hospital emergency with kidney infection
( atmosphere or water supply bourne ? our skies here have been filthy ! ).

Just home, and I look forwards to catching up, but I'm very shaky-weak-shattered.

So life's kinda on hold at the moment, but I do hope to be back kicking ball with everyone shortly.

Stay safe folks;

Cheers ............... Graham.

[john_g]

Can you share information on the magnet shown in post #173? Where you obtained it, overall size, space between poles, pole sizes, etc?

I'm putting together a parts list and am having trouble locating a suitable magnet. I can put together 10 pieces of neo magnets to make one but it's roughly $350 just for the pieces. That's more than half of the parts cost and I would like to get that cost down.

I did find some cloth covered wire that is 0.105" so that might have to do. The O.D. is not specified at the site but I left a message and they replied back with 0.105" O.D.
20 awg Solid Core, Cloth

Hi THX1138

You asked re the magnet-

Where you obtained it:

Given by a friend, it was ex railways, not sure what it was used for.

Overall size, space between poles, pole sizes, etc:

3" width,2" depth, 1 1/2" height. pole face 3/4" width x 1" height. Distance between pole edges 1 1/2"

Regards

John

[thx1138]

Pierce Arrow energy box

Re your Tesla (top ten) link, strange that there was no mention of his Pierce Arrow energy box ! I think that what we read depends upon who is publishing !

The interview was 1928. The Pierce Arrow was 1931 or later. What I've read on it indicates it was a 1931 Pierce Arrow but that doesn't necessarily mean it was new and the year was 1931. So it could have been '32 or '33.

[soundiceuk]

Hi, this company that sends me marketing media from time to time looks to be selling horseshoe neodymium magnets.

Win Magnetics Co.,Ltd

Web: www.winmagnet.com

Tel: 0086-(0)574-87405552

Fax: 0086-(0)574-87405558

Cell: 0086- 18858026663

Skype:Alvin.winmagnet

Add: Room 506,Unit 10,XinTianDi Plaza,YinZhou District,Ningbo City,ZheJiang China PR 315040


It has been suggested to me that Hendershot was using Radium. How true this is I don't know, but it sounds likely to me.


Best regards,

Paul

btw folks are falling for that really long video. I know some rich guy that was about to pay someone to build it. Not good. Luckily I saved him.

[Bob Smith]

Great to see the thread has moved on without me. Will catch up soon.
I ended up as an unconcious hospital emergency with kidney infection
( atmosphere or water supply bourne ? our skies here have been filthy ! ).

Just home, and I look forwards to catching up, but I'm very shaky-weak-shattered.

So life's kinda on hold at the moment, but I do hope to be back kicking ball with everyone shortly.

Stay safe folks;

Cheers ............... Graham.

Take care Graham. Thoughts and prayers are with you.
Bob

[Beamgate]

I ended up as an unconcious hospital emergency with kidney infection
( atmosphere or water supply bourne ? our skies here have been filthy ! ).

Just home, and I look forwards to catching up, but I'm very shaky-weak-shattered.

So life's kinda on hold at the moment, but I do hope to be back kicking ball with everyone shortly.

Stay safe folks;

Cheers ............... Graham.

Resonance to you Graham! Drink some 'distilled-water' for a well-deserved flush!

[thx1138]

winmagnet.com

Hi, this company that sends me marketing media from time to time looks to be selling horseshoe neodymium magnets.

Win Magnetics Co.,Ltd

I looked at their web site but didn't see any neo horseshoe magnets although they did show some in AlNiCo. They appear to be a manufacturer. I didn't see any way to buy their products on their web site nor any links to retailers or wholesalers. I'm not able to afford custom manufactured magnets for a prototype.

It has been suggested to me that Hendershot was using Radium. How true this is I don't know, but it sounds likely to me.

I haven't seen anything about Hendershot and radium but I haven't yet seen all the documents out there. That is very doubtful to me.

[Tishatang]

hi tech approach to hendershot

Hi All,

I just found this video re engineering a modern approach to hendershot. He discusses his ideas and how he is going to go about it. First in a new series of videos about hendershot.

Beyond Lester Hendershot / Part 1 - YouTube

He is not attempting to replicate orig, but his theories might give a clue about how the orig one worked?

Hope this helps?

tishatang

[GSM]

This evening is the first I've managed to think more about our work, though I'm far from recovered from illness.

Hi thx1138 -
good to see your meticulous analysis and approach.
There have been so many different 'documentations' that genuine originality is near imposible to find.
Thanks; will check out your vortex oscillator reference shortly.

Hi Paul,
Radium ? I did wonder similarly myself about this aspect after studying the Hendershot Generator. Heck, I even stopped considering that a Mk3 could run as stated, especially as Lester likely had access to radium paint as used on AirForce aeroplane instrumentation.
However, Lester's children are said to have run his early generators when he was not there, and I don't think any father would have allowed their children near radioactive substances unattended.
Besides, Lester's original model plane was a fully operational child toy, and Mark Hendershot himself would have been most aware of any radiation risks relating to a radium powered device, yet he has never mentioned such warning.

What turned my attention around with regard to Hendershot was my observation of Schmitt Trigger like reversals of magnetic field within a keeper oscillating about the 'neutral line' of a horseshoe magnet as per the Wesley Gary free electricity generator of 1879.
Wesley constructed and Patented his *free* electricity generator a full 50 years before Lester attempted likewise, however that granting was within a technological 'steam age' before electricity really started to flow, and Wesley's Patent would not have been deemed a financial threat as seen by the 'big money' men of Hubbard's and Hendershot's times.

So whilst Gary got his Patent, from the 1900s onwards there appears to have been authoritative controls of Grant and information release, this extending so far into present times that schools are deliberately providing our children with a flawed education.

Thanks for the good wishes Bob and Beamgate; at least I am getting stronger, and my brain is thinking again.

Earlier last month I had been doing some 'hands-on' testing of coil/armature assemblies in the presence of permanent horseshoe magnet fields.
An entirely radial physical movement of a horseshoe magnet closer to and away from an overwound keeper (as per Wesley Gary generator) can produce similar output as would be generated were the magnet to be rotating with respect to the overwound keeper !!!

This effect is common to both Wesley Gary's and Lester Hendershot's designs, and yet it is NOT something we taught about in school physics or even University ?

Magnetism is a *three dimensional*, electron orbit related phenomenon, with an unavoidable (and gyroscope translation like) field reaction at 90 degrees to the induced cause, also with a speed/frequency relationship related to the resistance/inductance of any coil overwinds involved.

I have never been able to find mention of the physical gaps which must have existed between Hendershot's 'buzzer' armature and both the magnet and coil assemblies, and yet, these must have been highly critical alignments relating not only to physical armature oscillation, but also to the cyclical and Schmitt Trigger like induced armature field reversals (as per Wesley Gary equipment), with corresponding armature to ringer coils transduction, and induced tuned (harmonic?) twin core-cap oscillation.
ie. almost square wave electrical output from the ringer cores via which the core-caps are induced to oscillate.

Cheers ............... Graham,

[thx1138]

Historical context

This evening is the first I've managed to think more about our work, though I'm far from recovered from illness.

Easy does it. Glad to hear you're doing better.

There have been so many different 'documentations' that genuine originality is near imposible to find.

Boy, that's the truth. My recent conundrum is the use of the word "buzzer". My research on old telephones led me to the fact that there were telephone ringers and telephone buzzers back in the day. From the pictures I've been able to locate they had very different actuating coils. Judging by the size of the coils in the pictures it appears the coils in the ringers is what was used. The buzzer coils appear to be about half as long as the ringer coils. I'm guessing it was called a "buzzer" because they made a buzzing sound in the Henershot device.

Radium ? I did wonder similarly myself about this aspect after studying the Hendershot Generator. Heck, I even stopped considering that a Mk3 could run as stated, especially as Lester likely had access to radium paint as used on AirForce aeroplane instrumentation.
However, Lester's children are said to have run his early generators when he was not there, and I don't think any father would have allowed their children near radioactive substances unattended.
Besides, Lester's original model plane was a fully operational child toy, and Mark Hendershot himself would have been most aware of any radiation risks relating to a radium powered device, yet he has never mentioned such warning.

There were no government controls on radioactive materials until the 1950's after they had been used in atomic bombs. And it turns out that the exposure guidelines that were developed at the time were extrapolated from the exposures seen at the Japanese bomb sites. Those guidelines are a subtle form of suppression. They set guidelines linearly while disregarding a known fact that there aren't any detrimental effects until a threshold is reached. Below the threshold level of exposure there is very little risk of detrimental effects but that known fact was quietly ignored and that is one of the reasons that radioactive substances are such a bugaboo today. Just mention radioactive materials and people shy away yet they are used in many, many products today like smoke detectors and those "powerless" light fixtures used in building stairways for emergency lighting.
Toxicologist says NAS panel 'misled the world' when adopting radiation exposure guidelines

BTW, radioactive materials can be purchased over the internet but they aren't highly refined or, for that matter, refined at all. You can safely hold them in your hand.

What turned my attention around with regard to Hendershot was my observation of Schmitt Trigger like reversals of magnetic field within a keeper oscillating about the 'neutral line' of a horseshoe magnet as per the Wesley Gary free electricity generator of 1879.
Wesley constructed and Patented his *free* electricity generator a full 50 years before Lester attempted likewise, however that granting was within a technological 'steam age' before electricity really started to flow, and Wesley's Patent would not have been deemed a financial threat as seen by the 'big money' men of Hubbard's and Hendershot's times.

So whilst Gary got his Patent, from the 1900s onwards there appears to have been authoritative controls of Grant and information release, this extending so far into present times that schools are deliberately providing our children with a flawed education.

Also note that the patents were in Canada and in that day one had to physically examine the patents - no internet, no photocopiers, and not even a fax machine and it wasn't until even the 1920's that telephone service could have been used to dictate a patent. I found some interesting Tesla patents in Canada as well and suppose that was a form of patenting where the location provided a little obscurity. RE education - since the government takeover of education it has become nothing more than propagandized indoctrination, imo. The real problem I see in today's education is that they are teaching what to think rather than how to think for one's self.

I have never been able to find mention of the physical gaps which must have existed between Hendershot's 'buzzer' armature and both the magnet and coil assemblies, and yet, these must have been highly critical alignments relating not only to physical armature oscillation, but also to the cyclical and Schmitt Trigger like induced armature field reversals (as per Wesley Gary equipment), with corresponding armature to ringer coils transduction, and induced tuned (harmonic?) twin core-cap oscillation.
ie. almost square wave electrical output from the ringer cores via which the core-caps are induced to oscillate.

That's got to be a crtical adjustment but it must also be variable based on the strength of the magnet, the area of the poles exposed to the armature, the armature size and material, etc., i.e. different magnet/armature/coil/coil core changes that gap.

I received the Pyramid caps I ordered and have taken the 40uF one apart but don't have anything to get an accurate measurement of the thickness. I'm going to pick up a Vernier caliper today. I did notice one interesting thing that someone may be able to explain: the two foils are somewhat different. One is shiny on both sides and the other is a dull gray matt finish on both sides. Different materials or maybe just a function of them being used?

Still working on the parts list but need the above measurements to complete it.

[citfta]

Capacitor forming

Hi thx,

After an electrolytic cap is assembled it is connected to a low current low voltage source and left like that for a while. Time depends on the size of the cap. The low voltage forms the cap into an electrolytic by causing one of the plates (foils) to form a coating on it. I think it is aluminum oxide but don't remember for sure. This adds capacitance to the cap and prevents current flow through the cap after it is charged. If you reverse the polarity the cap will have the coating damaged and allow current to flow through the cap. That is why electrolytic caps are all marked with a + and - symbol. If you exceed the voltage rating of the cap you will also damage the coating and create a short in the cap. I don't remember if it is the positive or negative foil that gets the coating. I think for what you are using it for it doesn't really matter about the coating as you are not using the dielectric material that was originally in the cap. Hope this helps some.

Respectfully, Carroll

[thx1138]

Capacitor forming

Hi, citfta. That explains it. I won't be using these materials from the Pyramid capacitor because they are the wrong size but I did want to get the thicknesses and generally satistfy my curiosity. Thanks.

[mikec_ut]

My Version of the MkI

@pjotterkjen
Sorry for the delay, time is not always kind for those that wait. I have got a PDF doc on my project and will attach it here.

There are lots of small experiments that I need to work on, association with this build. Hopefully I will be able to get a better Wild Ass Guess (WAG) as to wire size and coil size and placement as these experiments are completed. With my limited time experiment are slow but I am still working on this project.

[thx1138]

5:1 transformers

I'm still working on the materials list. There are a lot of 5:1 power transformers available. The documentation, however, says "Vertical Oscillator Type". I'm wondering if and what the difference would be between a "vertical oscillator type" and a power transformer. I'm guessing the docs are talking about either a TV or radar vertical hold or vertical sweep circuit and I have no experience with such circuits. I'm trying to determine the needed VA rating for the transformers. Any guidance will be appreciated.