Polorized capacitor re magnet charger

The stored energy in even one of those capacitors is more than enough to kill you several times.

Best thing for you, who only understands + and -, is to get assistance from a local electrician, or we shall be reading your obituary in the near future.....

Not quite THAT dumb. Do understand electricity fairly well. Built my own trouble free 110-220 volt dc power supply for my Monarch 10EE lathe some 20 some years ago with NO outside help. Finaly blew 1 of the 2, 10 amp line fuses with accidently locked rotor.(replaced with 15 amp) If someone would answer original questions with clear cut diagrams and info,will be appreciated.Never had the luxury of schooling beyond grade school and am never absolutly sure of symbols as many are similar. Am probably wasting everyones time with this post and will probably delete site from my files,yours,Ben

Thanks for input. Please READ replies # 3 & #17. Better yet,take the time to read ALL. I have been portrayed as a FULL bloomed retarded IDIOT!! AM only partialy bloomed!! The rotor being charged will be retained between poles of N & S coils via 1 3/4 in.mild steel bars bolted to steel cores which are in turn bolted to mild steel base. The afore mentioned plates are machined to fit the 1 1/2 in. dia magnetic rotor and locked against same. It will NOT move when being charged . My apoligies if i came across a little brisk in any of my replies. Again thanks to everyone.

Consult an experienced circuit designer, for safety reasons.

Not quite THAT dumb. Do understand electricity fairly well. Built my own trouble free 110-220 volt dc power supply for my Monarch 10EE lathe some 20 some years ago with NO outside help. Finaly blew 1 of the 2, 10 amp line fuses with accidently locked rotor.(replaced with 15 amp) If someone would answer original questions with clear cut diagrams and info,will be appreciated.Never had the luxury of schooling beyond grade school and am never absolutly sure of symbols as many are similar. Am probably wasting everyones time with this post and will probably delete site from my files,yours,Ben

Ben,

The answers that you have received were to deter you to kill yourself. What I can tell you is that those capacitors will hold a large amount of charge. By an accidental discharge, at the voltage seen across your capacitor, you might take a fair amount to knock you down, in the best of situations. Anyways, your capacitors are not rated for the voltage you intend to use, so even if you have a "bench" to charge them, they will explode. Do not know your configuration but, from a 120Vac, you can get up to 340Vdc. This is why you better take your project to an electrician, to be on the safe side.

You seem to get quickly upset when somebody tries to give you a friendly warning, you should be pleased that they took the time to do that as we can see from your post, that you have little knowledge or experience in this area...

I am not even sure that a normal electrician will be good enough here, they usually (in my experience) have little understanding of caps.....!

Sorry to be pedantic, but the other posters are correct, you can easily "Pop your clogs" with a finger in the wrong place here.....even with power removed. Therefore you must install "Bleed" resistors and carefully design to ensue that safety voltages (working voltages) are not even approached, let alone exceeded. Exploding caps will blind and deafen you.....the contents are generally poisonous too....

A silly question time - What is a magnet charger anyway?

The US and other Governements built magnetic rail guns for shooting down ICBM Missles using this force!

Original postee, What are the magnets for? Experimentation with motors?

WoW!! seems a bit tame after your post!!!!

Have you any interesting web sites for this process? I don't want to try it, it sounds more than a little dangerous if not carried out in the correct manner, anyway I buy my magnets when I need one!!

Quote:

The mechanical forces involved during such a discharge may be calculated, and are huge..

Unquote

I add to your comments

WARNING

Really it can Explode like a BOMB if the JIG is not STRONG enough to withstand the INSTANT FORCE

A well written description.

Such people should not do such job & may be dangerous for locality. Should deploy qualified & Experienced in manufacture of magnetisers.

Thanks for input. Please READ replies # 3 & #17. Better yet,take the time to read ALL. I have been portrayed as a FULL bloomed retarded IDIOT!! AM only partialy bloomed!! The rotor being charged will be retained between poles of N & S coils via 1 3/4 in.mild steel bars bolted to steel cores which are in turn bolted to mild steel base. The afore mentioned plates are machined to fit the 1 1/2 in. dia magnetic rotor and locked against same. It will NOT move when being charged . My apoligies if i came across a little brisk in any of my replies. Again thanks to everyone.

This idea (bank of super-capacitors suddenly discharging lots of energy) reminds me of another dangerous hobby that uses this approach -- making "shrunken" coins:

http://205.243.100.155/frames/shrinker.html

Thanks for input. Please READ replies # 3 & #17. Better yet,take the time to read ALL. I have been portrayed as a FULL bloomed retarded IDIOT!! AM only partialy bloomed!! The rotor being charged will be retained between poles of N & S coils via 1 3/4 in.mild steel bars bolted to steel cores which are in turn bolted to mild steel base. The afore mentioned plates are machined to fit the 1 1/2 in. dia magnetic rotor and locked against same. It will NOT move when being charged . My apoligies if i came across a little brisk in any of my replies. Again thanks to everyone.

I will not help ya to kill yourself, ya don't have the right stuff to work with

Thank you,Thank you. You have answered my questions and more without making me look like an IDIOTIC MORON. Can not thank you enough for such an intelligent reply.Will be attempting to charge alnico magnets on magneto rotor,not rare earth type. Hopefuly can restore the original charge on these 50 plus year old misused, tired rotors. PS the 10EE is a sweetheart.I bore all size Harley cylinders on it, in reverse, with extreme accuracy and finish. Anything you turn is easy and accurate.Thanks again,Ben

I don't want to trivialize the potential hazards when building and operating a magnetizer. When dealing with 1000Joules of energy you are talking greater than the muzzle energy of a 45ACP and less than a 30-06. However, unless you are committed to construct this thing, I suggest you look at eBay for a used motor. Even better, try http://www.practicalmachinist.com/vb/forumdisplay.php?f=10
These guys are converting their Monarchs to VFD drives and getting rid of the old motors cheap, sometimes free. Your ROI will be very poor if you construct a magnetizer for only one set of magnets. Please let us know how you decide to proceed.

Thanks for intrest.You are a few miles off track. The DC ,110-220 volt power supply i built over 20 years ago for my 10EE is still working fine.Please look at my original question and my othe replies,Re caps & mag charger.Yours,Ben

Ben,

These wouldn't be old Bendix magnetos would they? If so Bendix (Allied Signal) sold a unit to do this. All you had to have was an adequate D.C. power supply. One would place the rotor in the fixture, push button A to align the rotor magnetically, push button B, Bzzzzzt! re magnetized rotor. Nice hot mag every time! I don't know if they are even being sold new anymore as Bendix mags have fallen out of favor these days, but look around the net, I bet there are many used ones for sale. If nothing else a look at one my help you with your design.

shart

Thanks for reply. These are F.M. Very similar. Am on low budget,hence trying to use what i already have. The only used charger i have seen was priced WAY out of reality.Don,t think new charger is available any longer, plus price would be outrageous if still made.I realy DO appreciate everyones concern for my SAFTEY but Am NOT constructing a cycletron or a levated train,etc,etc, just want to recharge alnico rotors using 2 large coils with N. and S. orientation and give them a good momentary charge via the discharge of previously charged caps. Have worked with and used large caps in my DC welders and other equipment for 50 plus years. PS, any tips on winding coils on my lathe??

If you have a capacitor discharge welder, you have 95% of what you need to magnetize your magnets. Just put a well built magnetizing coil on the output transformer and you are finished.

Thank you for reply. Need 2 solenoid type coils, 1 south and 1 north oriented as am charging N & S poles of rotating magnetic rotor. (alnico) Original question,could 60 volt DC caps be wired to accept 110 volt dc charge?? In series?? Aparently no one reads ALL the posted questions and answers. Not sure what you mean by a cap discharge welder. My 300 amp P &H tig welder has several large caps,some as large as a small car battery,when i perform maintainance i double check they are discharged!! Yours,Ben

In short the answer is NO. A previous post stated that you should use a power supply to match the DC rating of the capcitors or they may explode.

As I understand them, capacitors have DC leakage. Unless that leakage is identical (not guaranteed any very unlikely) in each capacitor connected in series, they will charge to different voltages. The one with the greater leakage will charge to less than 55 volts, the lower leakage above 55 volts (possibly over 60 volts) and explode.

In order to make capacitors in series charge to the same voltage, resitors of identical resitance that are low enough in value to pass a current that is greater than the leakage current are connected across the capcitors. These discharge the capacitors and make the magnet charger inefficient and useless.

Please be careful, sudden powerful forces will be present during magnet reforming, as well as lethal voltages. Keep your hands behind your back, stand on a rubber mat, and dont touch any terminals!!

Connect a shorting stick to earth via a low, high wattage resistor, swith off the power supply and discharge the circuit fully before touching anything. I work with 20kV on linear accelerators, and these are the precautions I take

I don't know the configuration of your Alnico magnets. To charge a cylindrical magnet, you only require 1 solenoid because it creates both the North and South poles as any solenoid does. I suggest you do NOT attempt to wire your 60 volt capacitors to operate on 110 volts. Others are correct when they advise it is very risky. Better to use a DC/DC converter, however since you are not looking for efficiency, just use a voltage divider to obtain your 60 volts (MAXIMUM). No, you can not use your TIG welder. You could use a capacitor discharge spot welder. It sounds like you might think about letting someone who has the proper equipment, do this for you.

Thank you for knowlegeable answer and not treating me as an idiot. My initial question was-- Can 60volt,DC caps be wired to accept 110 dc charge-- If i was going to atempt this I WOULD NOT have bothered this site to ask. Short answer from ALL is NO. (Question answered,Thanks) I do have 2, DC 200 volt caps that should have more than enough amps to do the job. They should be safe to charge with 110 dc supply??? Would start out with 1 cap to see if coils i am making have enough gauss to charge the alnico magnets. The rotating magnets consist of a north and south pole,used to create high enough voltage to fire spark plugs as used on internal combustion engines(magneto) so will need 2 coils one S and other N .There are chargers and plans for chargers,but these will only charge the old horseshoe type magnets, not enough power(gauss) to recharge alnico.There are still a few places i could send them out to for a reasonable cost, but for my OWN reasons do not wish to.Thanks again everyone,yours,Ben.

http://www.freepatentsonline.com/5852393.pdf

http://www.freepatentsonline.com/5852393.pdf

Just stumbled on this thread. This comment is doubtless too late for urganb, but may be relevant for others with less extreme requirements
I strongly recommend against attempting series wiring urganb's conditions, even though it is possible in theory.

Capacitors can be wired in series, but you really need to know what you are doing. For example, you can use 60-Volt Zener diodes in parallel with each to equalise the leakage. However, the capacitors have to be of equal value, or you could easily blow the Zeners during charging; the energy involved is rather large, so that would be dangerous.
Similarly, if you are charging to a voltage, any defect in any of the capacitors could prove more than a little interesting. Once you have got all that correct, the biggest issue would be whether the capacitors are sufficiently rated for the discharge pulse - if not, they will all explode, taking you with them as like as not.

http://www.oldengine.org/members/rotigel/Magnet/

Thanks.Any chargers or plans listed there are not stromg enough for alnico, only for steel type.

Another plan might be to call 1-800-HUNTMAGS. They will rebuild your magneto for a reasonable fee. If the magneto is going into a stock engine, freshly charged alnico should be okay. If the engine is high performance, you might want to consider switching to rare earth magnets. They are the HOT set-up these days. Hunt can advise.

Thanks for reply. Have conversed with Hunt,also Morris. Please look at reply # 27, near end. yours,Ben

http://www.freepatentsonline.com/5852393.html

Thanks,but useless, does not adapt,nor apply to my application

If any-one has the experience of operation OR its Maintenance & Repairs of Manetisers he knows that:

1. Polarized [Electrolytics] are not used in Magnetisers as in spite of connecting Protecting-Diodes across Magnetising-Coil to suppress Hi-Energy Hi-voltage-peaks REVERSE due to Pulse fed to coil may destroy the capacitors. [ Back-EMF ] Electrolytics can withstand very-low reverse voltage.
This is the reason that Non-Polarised Caps are used.
one other reason is that it can be used as De-magnetiser just by disconnecting the Diodes Circuit & allow Ringing-Pulses due to back-emf effect across the Manetising Coil.

As the hi- DI/DT is needed for magnetising of a magnets Hi-Energy [Hi-Voltage Stored Energy ] so charged-energy @ lo-voltage are not considered suitable.

The construction of Magnetising Coil [Jig] is a very sophisticated job. It should be Heavy & Strong Structure with very Hi Permeability & lowest Retentivity.

Simple cables / wires are not used in Hi-Current, but Bus-bars are needed.

Switching by contactors or switches is not deployed, but Thyristors with very short
Turn-on-time & Hi I² * t

We have been constructing magntizers and welding equipment for more than 10 years using electrolytic capacitors. We have experienced no failures. We used to use non-electrolytics, but they are very large and expensive for this type of service. If the electrical and magnetic design is correct, one can get more than 50E6 discharges without failure. You can not expect an electrolytic to have a longer life than an oil filled, but you can get amazing performance for at least 10 years. Our equipment stores up to 8100 Joules.

Thank you for reply. Your reply realy does not lend itself to questions asked in original post.If you were to fully read posts# 22,24, 27 AND 35.you will better understand project.Thanks again,yours,Ben. (Better yet IF you have time,read all.)

Don't try using the 100 watt bulb as a resistor its resistence will change with the tempeature of the fillament, IE the bulb will have only couple of ohms when engerized and about 110 ohms when fully lite.

Hooray!!! Hooray!!! Sombody actualy read entire original post!!! And gave inteligent reply!!! I will now fry my feeble brain attempting to figure proper ohms resistor, as i am now scared to ask further questions on this site for fear of more ridicule.Thank you very much for your reply,yours,Ben.

Hello urganb, Ben,

"........as i am now scared to ask further questions on this site for fear of more ridicule....."

It is good to get feedback from you, thanks.

Just to say please don't be scared to ask questions on this site.

Many readers find that a pinch of humour, or a graphic in the reply makes for more reader interest.

As you may notice, CR4 is a public access website, and there are often some very unusual questions asked here, along with the frequent "impossible" question as posed by the most frequent question asker, with the User-name of Guest.

Because CR4 is a Community of people from different backgrounds and life experiences, as you ask more questions, and do some research to help others with their questions, you should find the CR4 Forum more interesting.

That is because you invest some of yourself into the lives of others, and thus have a sense of belonging more to this widespread Community.

Most at CR4 are not all folk who "ridicule" others, but some have a sharper sense of humour, and I am sorry you were unable to see that.

How about it then, Ben, forgive those whom may have offended you, and have another try, I'm sure you should find the Community an interesting place.

Hoping to see much more of you, on the CR4 Community Forum....