Re: + or - ground whats the difference?

Posted by jdemaris on January 25, 2005 at 06:41:13 from (209.23.30.39):

In Reply to: Re: + or - ground whats the difference? posted by Dave (IL) on January 25, 2005 at 06:22:33:

The polarity matters with some ignition coils because some have internal ballast resistors and/or diodes and you need the primary current coming in at the correct end of it all. So, some coils it makes no difference at all, and some it makes a big difference. I've got some charts around for various coils and their test output (for use on an Eiseman Coil tester). Quite a few coils are polarity sensitive and show a 30% drop in secondary output if not polarized correctly.
A non scientific approach that I use, since many older coils don't have much if any information printed on them - is to simply try the coil both ways and observe the spark gap it will jump.
As far a differences in winding counts and AL versus CU with different ground systems? I haven't got a clue. If there are no diodes involved - and there ARE sometimes - then it shouldn't make a difference unless I'm missing something. Take a starter motor and try it both ways. I've seen absolutely no difference in performance or current draw - positive or negative ground. Same goes for generators - you just need to polarize them correctly. So, it seems the field strength does not vary. Different story if you're fooling around with starters with permanent magnets.

Follow Ups:

• Re: + or - ground whats the difference? Steve(OR) 10:13:54 01/25/05 (1)
  • Re: + or - ground whats the difference? jdemaris 12:09:45 01/25/05 (0)
• Re: + or - ground whats the difference? Jon H 08:56:09 01/25/05 (11)
  • Re: + or - ground whats the difference? dr.sportster 13:47:02 01/25/05 (7)
    • Re: + or - ground whats the difference? dr.sportster 13:56:35 01/25/05 (6)
      • Re: + or - ground whats the difference? Jon H 15:16:47 01/25/05 (0)
      • Re: + or - ground whats the difference? dr.sportster 14:06:13 01/25/05 (4)
        • Re: + or - ground whats the difference? Jon H 14:24:37 01/25/05 (3)
          • Re: + or - ground whats the difference? dr.sportster 17:16:04 01/25/05 (2)
            • Re: + or - ground whats the difference? Jon H 20:52:49 01/25/05 (1)
              • Re: + or - ground whats the difference? dr.sportster 13:35:10 01/26/05 (0)
  • Re: + or - ground whats the difference? jdemaris 09:37:21 01/25/05 (2)
    • Re: + or - ground whats the difference? Bob 11:23:23 01/25/05 (1)
      • Re: + or - ground whats the difference? Jon H 14:07:03 01/25/05 (0)

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