Antique Engines and Old Iron
[Home] - [HELP] - [Forums] - [Library] - [Photo Gallery] - [Groups] - [Classified Ads] - [Subscribe] - [Links] - [Books] - [Sponsors] -

Go Back   SmokStak > SmokStak® Antique Engine Community > Magnetos, Ignition Coils and Spark Plugs
Forgot Password? Join Us!

Notices

Magnetos, Ignition Coils and Spark Plugs Discussion about magnetos, buzz coils, spark plugs, ignitors and low tension coils.

Magnetos, Ignition Coils and Spark Plugs

Condensors


this thread has 16 replies and has been viewed 1715 times

Reply
 
Thread Tools Display Modes
  #1  
Old 06-22-2018, 01:56:21 AM
cobbadog cobbadog is offline
Registered-III
 
Join Date: Aug 2009
Location: Coopernook. N.S.W. Australia
Posts: 1,589
Thanks: 2,958
Thanked 674 Times in 466 Posts
Default Condensors

Ever wondered what is inside the old condensors in the flywheel magneto of our mowers? I have, of course. Know I've stripped one down I want to know how it actually worked. It is made from 2 thin sheets of aluminium alfoil that is insulated by some very thin paper. Overall length is about 30" in old speak and the connections are just laid against the alfoil to make contact. this is obviously the most obvious point for a failure as it relies on a firm contact and in this case there was a type of corrosion between the contact and the alfoil. The braided wire is what went through the bottom of the brass outer casing and then soldered in place. The other end was soldered to the bottom of the threaded section that the points wire is connected to. The threaded section runs through an insulated washer.
With the alfoil I am not sure if it was all one length and I think it should be but when I got this apart it crumbled a bit and is no longer joined if it was originally. The wonders of electricity still astound me as to how this would hold a current until it was required to let it all go at once as designed.

Any takers on how this worked?
Attached Thumbnails
Click image for larger version

Name:	20180621_113103.jpg
Views:	187
Size:	112.5 KB
ID:	312861   Click image for larger version

Name:	20180621_113457.jpg
Views:	183
Size:	166.7 KB
ID:	312862   Click image for larger version

Name:	20180621_113855.jpg
Views:	164
Size:	139.5 KB
ID:	312863  
Reply With Quote
The Following 3 Users Say Thank You to cobbadog For This Post:
Sponsored Links
  #2  
Old 06-22-2018, 06:08:07 AM
Elden DuRand's Avatar
Elden DuRand Elden DuRand is offline
In Memory Of
 
Join Date: Nov 2004
Location: Port St. Joe, Florida, USA
Posts: 7,833
Thanks: 13,117
Thanked 7,895 Times in 2,966 Posts
Images: 11
Default Re: Condensors

A capacitor is simply two foil conductors (plates) held apart with an insulator (dielectric).

The area of the plates and the distance of separation of the two plates determine the "capacity" of the capacitor. The voltage the capacitor is capable of operating at is determined by the type and thickness of the dielectric.

The only reason some capacitors are rolled up is to make them fit into a smaller space.

Simply stated, capacitors work by storing a charge, sort of like a small battery but not having to use a chemical reaction to do it.

Capacitors resist a change of voltage between the plates sort of like a battery draws current from the charger until it's voltage matches that of the charger.

Now that you are totally confused, what else may I help you with?
__________________
[SIGPIC][/SIGPIC]
Take care - Elden
http://www.eldensengines.com
Reply With Quote
The Following 3 Users Say Thank You to Elden DuRand For This Post:
  #3  
Old 06-22-2018, 07:52:17 AM
PaulGray's Avatar
PaulGray PaulGray is offline
Subscriber
 
Join Date: Nov 2004
Location: Manson/Nixon Line, Maryland, USA
Posts: 621
Thanks: 1,097
Thanked 587 Times in 264 Posts
Images: 38
Default Re: Condensors

I've torn apart Model T coil condensers and seen waxed newspaper used as the dielectric...
Reply With Quote
The Following 2 Users Say Thank You to PaulGray For This Post:
  #4  
Old 06-22-2018, 08:07:12 AM
Thaumaturge Thaumaturge is offline
Subscriber
 
Join Date: Mar 2014
Location: Beryl, Utah USA
Posts: 4,457
Thanks: 3,492
Thanked 4,674 Times in 1,961 Posts
Default Re: Condensors

All just extensions of the technological principles of the original Leyden jars, which were just glass or ceramic jars coated with a metalic film on both the inside and outside, but inside and outside issolated from each other. The walls of the jars serving as insulating dielectric. You can create your own by lining both the inside and outside of a Mason caning jar with aluminum foil... but if you do treat them with respect, for even such a simple capacitor can (and will) bite HARD!
Doc
__________________
In my younger days my focus was more upon hedonistic pursuits and behavior.... I really miss those days.
Reply With Quote
  #5  
Old 06-22-2018, 11:17:18 AM
turbo's Avatar
turbo turbo is offline
Subscriber
 
Join Date: Dec 2006
Location: Heron Lake, Minnesota, USA
Posts: 1,095
Thanks: 627
Thanked 1,050 Times in 443 Posts
Default Re: Condensors

Quote:
Originally Posted by PaulGray View Post
I've torn apart Model T coil condensers and seen waxed newspaper used as the dielectric...
I guess Henry Ford was serious when he let nothing go to waste!
Reply With Quote
The Following User Says Thank You to turbo For This Post:
  #6  
Old 06-22-2018, 11:50:55 AM
Power Power is offline
Registered-III
 
Join Date: Aug 2011
Location: New Jersey
Posts: 5,110
Thanks: 1,176
Thanked 3,014 Times in 1,775 Posts
Default Re: Condensors

Be careful with old capacitors

Due to the electrical insulating properties, lack of flammability,
chemical and thermal stability of polychlorinated
biphenyls (PCBs) were often used as dielectrics in paper capacitors.

Because of their hazardous impacts on human health (BAG 2006) and their extraordinary stability, the production and application of PCBs was internationally
banned, first in open systems in 1978 and then prohibited in 1986 (UNEP 1999).
Reply With Quote
The Following User Says Thank You to Power For This Post:
  #7  
Old 06-22-2018, 01:56:24 PM
Harry's Avatar
Harry Harry is offline
Administrator
 
Join Date: Oct 2004
Location: Sarasota, Florida USA
Posts: 6,672
Thanks: 558
Thanked 13,696 Times in 2,338 Posts
Images: 319
Default Re: Condensors


Condensor Construction

A capacitor or condensor is used across the contacts to aid in the rapid field collapse and to reduce contact arcing thus extending the life of the points. (The condensor absorbs the self-induced current of the primary winding, preventing it from opposing the rapid fall of the primary current.) Early condensors were made up by alternating layers of tin foil and paraffined paper, cut to the same size, like the pages of a book. Even numbered foil sheets were connected together for one polarity and odd numbered sheets were connected together for the opposite polarity. These connections were then routed to each side of the breaker points.

Old-Engine Magneto Page: https://www.old-engine.com/magbuz.htm

Changing the condensor (capacitor) on a Bosch AB-33 https://www.smokstak.com/forum/showt...746#post152746



AB-33 magnet charging setup: https://www.smokstak.com/forum/showt...962#post146962
__________________
-- Harry Engines Ignitions Videos Photos
Reply With Quote
The Following User Says Thank You to Harry For This Post:
  #8  
Old 06-23-2018, 12:58:48 AM
Beanscoot Beanscoot is offline
Registered-II
 
Join Date: Oct 2007
Location: Victoria, BC Canada
Posts: 360
Thanks: 23
Thanked 106 Times in 68 Posts
Default Re: Condensors

You can understand how they can fail after a few decades, especially in damp storage, when you see how they are made.

For that matter, you can see why modern Chinese ones often are BOOB (bad out of box).
Reply With Quote
The Following User Says Thank You to Beanscoot For This Post:
  #9  
Old 06-23-2018, 01:57:45 AM
cobbadog cobbadog is offline
Registered-III
 
Join Date: Aug 2009
Location: Coopernook. N.S.W. Australia
Posts: 1,589
Thanks: 2,958
Thanked 674 Times in 466 Posts
Default Re: Condensors

Thank you so much to ALL who have replied and in a way that my simple mind has understood. Now for the big challenge, remembering it all.

It is help like this that makes these Forums so very helpful.
Thank you once again.

On another topic that was touched on, Henry ford. his use of waxed newspaper was just one of many items he recycled. He used the wooden engine crates to make the floors in the old "T" model. One very clever man way ahead of his time.
Reply With Quote
  #10  
Old 08-21-2018, 08:06:17 AM
dkamp dkamp is offline
eMail NOT Working
 
Join Date: Oct 2007
Location: LeClaire, Iowa, USA
Posts: 1,525
Thanks: 32
Thanked 783 Times in 517 Posts
Default Re: Condensors

Actually deeper than just using the crates to build his floors: He SPECIFIED the shape of the crates, the type of wood, and the FILLER MATERIAL. One of my dad's Model As was in original, unrestored condition, and the seat filler material was spanish moss, apparently from Florida. Some part, component, or supply was ordered, and the packaging material was specifically identified.

There's nothing spectacular about this- it's simple conservation, at least on Henry's end. On many cases of his suppliers' end, it cost substantially more to contract those supply sales.

As for making condensers, he may have started out making his own, history proved that specializing had it's advantages, specifically in the quality control aspect of more sensitive parts. It's one thing to make a condenser, it's yet another to make one that is consistent, accurate to its desired value, durable, AND inexpensive. From what I see, Henry seemed to always be most concerned about inexpensive, and he was very protective about keeping all manufacturing in-house so as to never be under the 'leverage' of others, but often faced music of reality when stuck with poor parts. He may have made his own condensers for prototypes, but didn't make condensers in production quantities for the Model T... the condenser was an integral component to the buzzer coil, which he had produced by others. K-W was the most common, IIRC.
Reply With Quote
  #11  
Old 08-21-2018, 11:31:20 AM
I like oldstuff I like oldstuff is offline
Subscriber
 
Join Date: Jan 2012
Location: Milwaukee, Wisconsin, USA
Posts: 5,953
Thanks: 1,483
Thanked 6,692 Times in 2,520 Posts
Default Re: Condensors

A while back some enterprising techs in the shop discussed stacking 4 foot square sheets of raw circuit board material to create a capacitor. When I heard a couple loud bangs coming from the shop I went downstairs to see a few guys laughing. They charged this thing with a 1 kV supply and had it connected with some 200 MCM cable.

They had fun vapourising some wire etc. After I turned on my Mr. manager personality they got hella lecture out of me. One guy was bitching about the lecture which earned him a three day suspension. What they didn't realise that something as big as this stack of about 50 sheets is prone to some charge migration. It'll recharge itself a bit after the initial pop. I had them short everything out for a few hours and put the non damaged sheets back in inventory. Yes, about ten of them were junk from the internal arcing.

I have no idea as to the farad capacity of this stack but it had to be big.
Reply With Quote
  #12  
Old 08-21-2018, 11:56:38 AM
Beanscoot Beanscoot is offline
Registered-II
 
Join Date: Oct 2007
Location: Victoria, BC Canada
Posts: 360
Thanks: 23
Thanked 106 Times in 68 Posts
Default Re: Condensors

Well at least they weren't electrocuting each other!
Reply With Quote
  #13  
Old 09-28-2018, 05:10:33 PM
Pennsy Pennsy is offline
Registered
 
Join Date: Jul 2012
Location: Mifflintown, Pennsylvania
Posts: 35
Thanks: 27
Thanked 6 Times in 4 Posts
Default Re: Condensors

So what is a GOOD brand name condenser for these engines if there is such a thing? I need one for in a Wico EK mag. And how do you know what condenser to use
Reply With Quote
  #14  
Old 09-28-2018, 10:40:39 PM
JoeCB JoeCB is offline
Subscriber
 
Join Date: Feb 2008
Location: Farmington Hills, Michigan
Posts: 577
Thanks: 99
Thanked 354 Times in 181 Posts
Default Re: Condensors

Quote:
Originally Posted by Pennsy View Post
So what is a GOOD brand name condenser for these engines if there is such a thing? I need one for in a Wico EK mag. And how do you know what condenser to use
I'm into old outboard motors , most have simple flywheel magnetos, Eisemann, Wico, Johnson, Evinrude etc. Within the antique outboard community ( aomci.org) much research has been done to record info about magneto components, especially the capacitors. capacitors are the only component in a classic mag that has a "shelf life". Yes, a capacitor, especially the old style waxpaper/ foil ones will deteriorate with age even if not used.
If you look at many mag spec sheets for capacitor size ( electrical capacitance. micro- farads) you will see that very many call for a cap in about .22 mf rated for at least 300volt. A modern plastic foil capacitor that we have found that does a super job in all the instances that we have tried is made by Vishay, .22mf rated at 850v .(available from electronic component supply houses , I us Digikey) These are small enough to fit in any mag. and for those that want to keep the original look, the Vishay cap can be creatively fit into the metal can of the old waxpaper cap.


Joe B
Attached Thumbnails
Click image for larger version

Name:	V condenser.jpg
Views:	41
Size:	107.1 KB
ID:	319808  
Reply With Quote
The Following 2 Users Say Thank You to JoeCB For This Post:
  #15  
Old 09-29-2018, 12:41:19 AM
cobbadog cobbadog is offline
Registered-III
 
Join Date: Aug 2009
Location: Coopernook. N.S.W. Australia
Posts: 1,589
Thanks: 2,958
Thanked 674 Times in 466 Posts
Default Re: Condensors

For my vintage mowers and magnetos for the stationary engines I too use a film capacitor rather than a condensor now.
I buy them from the local electronic store or buy them in bulk online at the usual auctions sites.
These come in various physical sizes and again as described can be inserted inside the original canister if required. I get 0.22Mf 640V and made with a ceramic coating to help insulate from any heat.
Reply With Quote
The Following User Says Thank You to cobbadog For This Post:
  #16  
Old 09-29-2018, 07:35:28 AM
Pennsy Pennsy is offline
Registered
 
Join Date: Jul 2012
Location: Mifflintown, Pennsylvania
Posts: 35
Thanks: 27
Thanked 6 Times in 4 Posts
Default Re: Condensors

Quote:
Originally Posted by cobbadog View Post
For my vintage mowers and magnetos for the stationary engines I too use a film capacitor rather than a condensor now.
I buy them from the local electronic store or buy them in bulk online at the usual auctions sites.
These come in various physical sizes and again as described can be inserted inside the original canister if required. I get 0.22Mf 640V and made with a ceramic coating to help insulate from any heat.
Could you post a link of one that you'd typically buy on ebay?

Here is a picture of my existing one. There's no markings on them, that's the thing.
Attached Thumbnails
Click image for larger version

Name:	DSC00122.jpg
Views:	40
Size:	149.5 KB
ID:	319820  
Reply With Quote
  #17  
Old 09-29-2018, 07:36:42 AM
Pennsy Pennsy is offline
Registered
 
Join Date: Jul 2012
Location: Mifflintown, Pennsylvania
Posts: 35
Thanks: 27
Thanked 6 Times in 4 Posts
Default Re: Condensors

I've got spark, its just weak and I was aware the condensors deteriorate so are suspect for weak spark.
Reply With Quote
Reply

Bookmarks


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

F o r u m Jump


Use "Ctrl" mouse wheel to change screen size.
All times are GMT -4. The time now is 02:22:20 PM.

Smokstak and Enginads site search!


All use is subject to our TERMS OF SERVICE
SMOKSTAK® is a Registered Trade Mark - A Community of Antique Engine Enthusiasts
Copyright © 2000 - 2019 by Harry Matthews P.O. Box 5612 - Sarasota, FL 34277