How To Build A Magnet Charger (Guide)

[Joe Gwinn]

I built Gingery's magnetizer myself a few years ago, but IMO it didn't really have quite enough oompf to get magnets completely charged even at 10A measured at 120VAC input. I was thinking about some kind of power amp for it to raise the energy going to the coils to do a better job. I used modern 150C rated coil wire, and a cap bank made of 500VDC caps (mil surplus) too.

I don't have the Gingery book. Is this a capacitor-discharge unit, or are the 500-volt capacitors used for filtering the rectified AC?

[rhgwynn]

I don't have the Gingery book. Is this a capacitor-discharge unit, or are the 500-volt capacitors used for filtering the rectified AC?

I think it's a cap-discharge; which is common for a industrial magnetizer.

-Rob

[Joe Gwinn]

typo

I think it's a cap-discharge; which is common for a industrial magnetizer.

Maybe there are two Gingery designs. I recall discussion of one that was just a big electromagnet driven by a rectifier off the AC line.

If it's capacitor discharge, one problem is that the capacitor can resonate with the coil, causing field reversals, which demagnetize the magent, and will destroy the caps if they are electrolytic and not in a protective circuit.

Does anybody have the book? If so, if they publish a scan of the circuit from the book, I'll be able to tell.

[copperheadroads]

Maybe there are two Gingery designs. I recall discussion of one that was just a big electromagnet driven by a rectifier off the AC line.

If it's capacitor discharge, one problem is that the capacitor can resonate with the coil, causing field reversals, which demagnetize the magent, and will destroy the caps if they are electrolytic and not in a protective circuit.

Does anybody have the book? If so, if they publish a scan of the circuit from the book, I'll be able to tell.

Here's a crude pic of Gingery's schematic

[Joe Gwinn]

Here's a crude pic of Gingery's schematic

This is not a capacitor-discharge circuit.

This is a simple full-wave rectifier (25 A, 200 V) with smoothing filter capacitor (100 MFD) driving a field coil (Coils) with the resulting direct current.

What is the DC resistance of the coil, and how many turns of wire does it have? The intent is to compute the ampere-turns.

[nutgone]

Hi, I got directed to this forum when doing a google search for building a magneto charger, but the images aren't coming up. I've tried everything, are they no longer hosted? Anyone know where I can get this building guide from?

Still, it's been fun looking round here. Nice friendly forum with some surprisingly helpful stuff.

[Joe Gwinn]

Hi, I got directed to this forum when doing a google search for building a magneto charger, but the images aren't coming up. I've tried everything, are they no longer hosted? Anyone know where I can get this building guide from?

Still, it's been fun looking round here. Nice friendly forum with some surprisingly helpful stuff.

You mean posting #10, above? Just tried it. It works for me. It's a video, not a still picture.

[J M Fahey]

Maybe he means post #1 , the one which claims "BIG images", it's empty in my browser.

FWIW I have 2 brute force speaker magnetizers, and of course they easily magnetize any kind of pickup.

[nutgone]

Thanks guys. I did indeed mean post number 1, the original post. It's completely empty in my browser (I use Google Chrome, maybe that has something to do with it).

But, I have since found a link which displays all 5 pages of the device build. Should I put it up here? (never know if I'm allowed to when new to a forum). It might help stop any future newbies coming along & digging up old threads (like I just did ).

[Joe Gwinn]

Thanks guys. I did indeed mean post number 1, the original post. It's completely empty in my browser (I use Google Chrome, maybe that has something to do with it).

But, I have since found a link which displays all 5 pages of the device build. Should I put it up here? (never know if I'm allowed to when new to a forum). It might help stop any future newbies coming along & digging up old threads (like I just did ).

It's empty in my browser too. Feel free to post the links and/or material

[David King]

Doesn't Gingery sell all his booklets on ebay? It's undoubtedly copyrighted material and TBoy may have taken it down as a result.

Here, I found it on Amazon. http://www.amazon.com/Build-Magneto-.../dp/1878087452
There are plenty of photos and discussions on a forum called smokestack -whatever that is.

[nutgone]

This isn't actually Gingery's plans, this one was made by a man called John Rex & the entire plans were published in the January 1989 edition of "The Gas Engine Magazine". The link below is from another website, so I'm not posting anyone else's material, just a link to another web page (where someone else is showing other people's material )....

Magnet Charger Contruction Page 1

I have since downloaded the images to my computer & printed them off for future reading (when funds & workshop facilities eventually allow me to build such a device).

[David King]

Wow, 20,000 Amp turns is at least 2 x more than we'd ever need for pickup magnets but as the guy says it can't hurt anything. I assume the 150 pounds is partially the car battery. If it's all iron and copper it's going to be a rather expensive item to put together.

[ken]

That new magnetizer design would NOT be cheap to make either. Gingery's basic design was OK, but I thought it just didn't get enough power.
I wonder what would happen if I took all the rectifier stuff out of mine and hooked it up to a car battery?

ken

[nutgone]

I plan to power mine from my workshop welder. It's around 20 volts (or so) & goes from 10 right up to 150 amps. But I also have a pretty heavy duty car battery I can use as well if the welder doesn't like magnetising.

The welder is an inverter based machine (basic model for TIG & Stick welding), I have no idea what the output wave looks like though. I would guess these magnetisers prefer the flat-line DC of a battery to an non-smoothed rectified AC current. But I could also smooth out some AC if I had to, I was going to build my own welder a while back & wound 2 large smoothing chokes onto old microwave oven transformer cores. Sure I could pick up some good sized capacitors as well, if needs be.

I also have an oscilloscope, maybe I should dig it out & connect the welder up, see what the output looks like. I could experiment with my home made smoothing chokes (otherwise known as reactors in welding speak, I believe) see if they actually do anything.

As for cost, no it definitely wouldn't be cheap, but finding a good used magnetiser is next to impossible, especially here in the UK. If I had to I would turn the amps down slightly & increase the number of turns on each coil, meaning I could use thinner (cheaper & more readily available) wire whilst (in theory) keeping the same ampere-turns ratio, thus the same "power" (this, I believe, is where the Gingery plans differ from these plans). Not sure i this actually rings true though as more resistance is introduced with thinner wire & more length.

I'm guessing multi-strand cable or flexible wire is a definite no-no here? Our household cable here in the UK is a kind of semi-flexible stuff, usually made up of just 7 cores of smaller copper (sometimes shaped to fit together more snugly) twisted & insulated. Flex of the same gauge would probably have 50-100+ separate cores twisted together (like welding cable). I understand multi-strand cables & flexes don't work well in transformer cores due to eddy-currents circulating each separate core/strand of the cable??? (Guess that leaves me looking or some hefty single strand wire).

I also wonder if aluminium conductors would be cheaper as copper but just as effective (or as close as necessary)???