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Jul 10th, 2022
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Joined: Aug 2001
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Britbike forum member
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Britbike forum member
Joined: Aug 2001
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Hi, Harley dual output coils have no markings on the primary terminals... ... which probably reflects that, with ignition coils, doesn't really make any difference which way you connect 'em, they still produce an HT spark?  Regards, On an HD-type dual output coil, the secondary winding is electrically isolated from the primary winding, so it makes no difference which way the primary winding is connected, polarity speaking. On a single output coil, one end of the secondary winding (the end NOT connected to the HT lead) is connected to one end of the primary winding. This end of the primary winding should be connected to "ground". As was stated above, the coil will still produce a spark if hooked up "backwards", but then the secondary current must go through the primary winding on its way to "ground". Since the primary winding is only in the vicinity of 3 to 5 ohms, the effect is negligible, as observed by 68 royalstar tony.
Mark Z
'65(lower)/'66(upper, wheels, front end, controls)/'67(seat, exhaust, fuel tank, headlamp)/'70(frame) A65 Bitsa.
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Joined: Jan 2014
Posts: 2,167 Likes: 374
Britbike forum member
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Britbike forum member
Joined: Jan 2014
Posts: 2,167 Likes: 374 |
it's got to be a german thing.
i used to deliver steel to a german-owned warehouse in chicago. an immense place-- 60-foot high racks of bar, angle, tube, and strap, all shapes and sizes, stored lengthwise in little cubbyholes, hole after hole, rack after rack.
the unloaders would crane the steel off my truck onto a table, and then punch a series of buttons to tell the computer where to pick up the steel, where in the warehouse to take it, and which cubbyhole to shove it into. then the automatic overhead crane would loom into view and take it away.
as i remember, the keypad was about fifteen buttons across and a dozen buttons high. all the buttons were labelled with individual and unique icons to tell the operator which button told what to the computer. but because there were so many functions, the icons were incomprehensible-- squiggles, squares, lightning bolts, zigs, zags, stars, and triangles. the symbols were all unique, but there was no ergonomic symbolism visible anywhere. couldn't tell what the buttons did.
attached to the side the keypad was a manufacturer-supplied key to the buttons in english, with words to tell the operator what crane actions corresponded to what symbol, so he could go to the keypad and punch the correct buttons.
by doing it this way, the germans had to provide each destination country with two sets of instructions-- one universal keypad with the heiroglyphics, and then a matching language-coded sign to interpret the symbols.
nobody in germany ever thought to just put the language-codes (which they had to make up anyway for each country) on the buttons themselves, and then to just skip the icons. Ever heard of the Enigma machines?????
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3 members like this:
Mike Baker, kommando, JER.Hill |
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Joined: Jan 2004
Posts: 5,419 Likes: 177
Britbike forum member
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Britbike forum member
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"if hooked up "backwards", but then the secondary current must go through the primary winding on its way to ground" - yes, however, the spark is created by the points opening so for the secondary current to make a full path it has to jump the open points or go through somewhere else, typically the battery plates where the internal resistance is an Ohm or so. On a dual output coil with separate windings the polarity difference changes which plug is fired in reverse.
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Joined: Aug 2001
Posts: 5,905 Likes: 116
Britbike forum member
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Britbike forum member
Joined: Aug 2001
Posts: 5,905 Likes: 116 |
"if hooked up "backwards", but then the secondary current must go through the primary winding on its way to ground" - yes, however, the spark is created by the points opening so for the secondary current to make a full path it has to jump the open points or go through somewhere else, typically the battery plates where the internal resistance is an Ohm or so. Hmm right, I was thinking electronic ignition, where the coil is always grounded. That raises an interesting question though, in the breaker points case, how does the secondary current get back to the other end of the secondary winding, even when hooked up "frontwards" (i.e., correctly), if the points are open when the spark occurs? That would imply going through the battery is normal. I know there's not much current since most of it is consumed by the spark, so I guess that's ok, but it's not intuitive (to me).
Mark Z
'65(lower)/'66(upper, wheels, front end, controls)/'67(seat, exhaust, fuel tank, headlamp)/'70(frame) A65 Bitsa.
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Joined: Jan 2014
Posts: 2,167 Likes: 374
Britbike forum member
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Draw it out and you'll see.
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Joined: Oct 2008
Posts: 7,841 Likes: 280
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Joined: Oct 2008
Posts: 7,841 Likes: 280 |
It's not a bug, it's 'character.'
72 T120V cafe project "Mr. Jim"
72 T150V "Wotan"
92 BMW K100rs "Gustav"
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Joined: Nov 2015
Posts: 31
Britbike forum member
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Britbike forum member
Joined: Nov 2015
Posts: 31 |
Ahh, yes German engineering like the cable operated hydraulic brake cylinder under the tank on my 76 BMW R/90 and the complicated throttle twist grip system. But they do work so......I live with them.
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