[SEL] Recharging of Maytag coils

[bill at antique-engines.com]

Having a degree in automotive technology, earned when points were still in
use to some degree, here's why I state that it MAY, mind you MAY not start
and/or run, or run properly:

When the points open, the sudden loss of primary current causes a quickly
collapsing magnetic field in the coil which induces a larger voltage in
the secondary windings. The voltage traveling through the secondary
winding in turn induces a current flow, in reverse, in the primary circuit
- enough to cause the points to arc.
This “back emf” is due to the design of the ignition coil and its inherent
inductance.  This feedback of electrical energy causes a spark to occur at
the points that pits and erodes the contact surfaces.  To suppress this
energy, a condenser is used.  It acts like a shock absorber (absorbing the
back emf), ** and in so doing it helps to interrupt the primary current as
quickly as possible when the points open.
Without the condenser, the back emf would form an arc across the points as
they separate, ** slowing the collapse of the coil’s field, thus delaying
and thereby reducing the voltage rise in the secondary coil winding -
~possibly~ reducing it enough to cause it to not span the plugs gap.  The
condenser suppresses most, but not all of the back emf. So points still
burn or erode.

Bill

> It should start and run without the condenser but only till the
> points burn which can be fairly quickly. The condenser has little to
> do with the actual generation of spark, more to do with the
> protection of the points from arching and burning quickly. If you try
> it without a condenser gap the points a bit wider then the spec .020
> to get a clean break or so that the arc flame between the points does
> quit due to width of gap.        Mark
>
>
> At 02:11 PM 6/8/2009, you wrote:
>>Good chance it won't start at all without the condenser - may cause
>> points
>>to arc and not break cleanly.
>>
>>Bill
>>
>>
>> > Hi Mark,
>> >          (Actually to Mark Shulaw but kept on the lists for others to
>> read
>> > and learn!!)
>> >          Just a quick update.
>> >          I took the drive to my friend (70 miles away) yesterday and
>> he
>> > recharged the magnets for both twins for me. Very impressive, I've
>> never
>> > seen this done before.
>> >          They previously only attracted a screwdriver - now you can
>> pick
>> > the whole flywheel up with a lathe tool !!
>> >          Unfortunately this was quite late yesterday so I could not
>> "play"
>> > with the engine but it did appear to start easier (still with the
>> electric
>> > drill) and ran a little smoother. Today was work (day job) again so
>> I've
>> > not been able to do anything to the Maytag - next step is to try and
>> start
>> > without the condensor. (I still cannot start it easily with the kick
>> > start!).
>> >          I will first try with the condensor disconnected (but will
>> not
>> > run
>> > it for any length of time like this). If this gives me a better spark
>> then
>> > I'll replace the condensor. Can you tell me if I can use any car
>> condensor
>> > (I've ordered from you but in the meanwhile should I go out and buy a
>> > condensor from a lawnmower engine (eg. Briggs & Stratton) to try with.
>> >          I do not know anything about how condensors are "rated" and
>> also
>> > know that if I went to one of the local "auto spares" shops that they
>> > would
>> > also not know the difference. My friend (who recharged the magnets)
>> > suggested a lawnmower engine condensor as these are for a magneto.
>> >
>> >
>> >
>> >
>> >
>> > Keep the revs up (or down)
>> > Jerry Evans
>> > Near Johannesburg in Sunny South Africa.
>> > Etched Brass Engine Plates made to order:
>> > <www.oldengine.org/members/evans/plates/index.htm>
>> >
>> >
>> >
>> > _______________________________________________
>> > SEL mailing list
>> > SEL at lists.stationary-engine.com
>> > http://www.stationary-engine.com/mailman/listinfo/sel
>> >
>>
>>
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>
>
> Mark Shulaw
> 454 Co. Rd. 33
> Bluffton, OH. 45817
> USA
>
> Frappi at wcoil.com / 419.358.5206  Home / 419.516.2996 Ver. Cell.
> Hobby Collector and Dealer in Maytag Multi-Motor Engine parts.
> VISIT the Maytag Collectors Club at  www.Maytagclub.com
>
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