Red OMC coils

[51seahorsetn27]

Seems if the module is using a transistor the polarity of the magnet and wrapping, voltage induced would make a difference depending on which leg the leads are attached to the transistor. But transistors only travel one direction of current flow, then the difference between pnp and npn would make a difference but still current flows from collector to emitter via modulation of the internal film. That still doesnt really explain why the coil wrapping has to be specific for the module. Thats an oddity unless the magneticism has an affect on the radio frequency induced on the coil via module pulsation. Similar to emp on an automobile, remember the old days when they used a capacitor or something similar in the alternator circuit to stop radio interference, that also helped keep early voltage regulators an distributor modules from frying as well.

[debe]

The reason the polarity has to be right is that some coils have a Negative pulse & others have a Positive pulse which triggers the module.

[rudderless]

quote 51SeaHorseTN27:

That still doesnt really explain why the coil wrapping has to be specific for the module.

I’m not sure of your level of understanding but if you Google "right hand rule" for mag flux/current direction the answer will be there..

my apologies if that is old news..

[debe]

It doesn’t have to be specific. If it doesn’t suit the module then you just reverse the way the module is connected.

[51seahorsetn27]

I got the idea of the coils producing diferent polarity pulses, i am a little rusty on the right hand rule so ill peek at it when i get a chance.What I am really questioning in what you quoted, was kind of thinking out loud, more or less is why the coils just arent all wrapped the same and produce one pulse across all types for ease of the end user. But again we know that it is not that way for what ever purpose.

[joesnuffy]

Here is a neat picture of the Red Coils I found in my 1958 7.5hp Johnson. When you turn them up on their side they are clear so you can look through them and see the windings. I am guessing you would be looking at the primary windings?

I am also attaching a pic of the TIP 102modules I had in the 33hp. I did not put a mosorb diode on them to protect them to see if they would die or not which they did. I have 2 more built modules with the 102s I will try them with the diodes to see if they live with the purple coils. Since this engine has kill wires to magneto I will re-purpose them to mount the modules outside flywheel for testing purposes. Notice in this picture the motor has purple coils in it and the small wires from coil wire up as normal. I do think the purple coils may be hard on modules like these and the Nova’s.

I was also thinking that if a person had the ground wire for coils running to the outside of the magneto where they could switch them to ground or to a set of modules they could leave the points and condensers in place and switch between them so if your modules died you could switch back to points or you could also switch back to points to see how the motor runs compared to the modules.

One last thing I have not lost any Nova 2 modules using the Black Coils that marine engine sells. They are the ones below. I do need to do some more run time on them. If memory serves me correctly I think I have seen the word cdi used with them before which would be capacitor discharge ignition which I noticed these coils are used on a variety of motors up to 1990 this may make them more compatible with modules. I need to do more testing on that I have a pair in my 9.5hp. In a CDI enviroment they may limit the power produced by their coils since the electronics are more sensitive which would explain why the older omc coils kill modules/novas they were not designed for them.

http://www.marineengine.com/newparts/pa … OMC0584477

Joe

ps here is where I have seen the word cdi. I have a pair of them also which I was running in a 5.5hp with nova 2s Didn’t loose them either. I will try these coils also using the home made modules to see if they live as soon as the Momma Bird has her babies. I was waiting on a base gasket for power head for this motor with the magneto off and the pull start off a bird build a nest in it in like 2 days and layed her eggs. The wife told me to leave her alone and her eggs alone dang it!!!.

http://www.marineengine.com/newparts/pa … DI183-4477

It is possible that any of these coils on this page are good to go with cdi except possibly the sierra seems like they have a problem with quality. Notice that is also where the black coils are

http://www.marineengine.com/parts/johns … neto+Group

[Author]

Posts