Author Topic: New "Modelengine" Ignition Coil  (Read 4585 times)

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ahowell

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New "Modelengine" Ignition Coil
« on: June 29, 2010, 08:43:42 PM »
We now offer the new "Modelengine" Ignition Spark Coil. This coil is about half the size of the "Exciter" and will power most all of Jerry's IC engines with no trouble (the exception is the V4, which we recommend using the "Exciter" coil). This coil contains three prongs at one end, one for +, one for -, and the third for the spark plug.  Like the "Exciter", the coils are totally enclosed in a plastic cylinder and potted with epoxy. This makes them very rugged and oil/fuel proof. These coils can be used on any model spark plug type engine with the TIM-6 transistor ignition module.

Specifications: .980" Diameter by 1.250" long, primary resistance: 1.2 Ohms, secondary resistance: 4.9K Ohms, operating voltage: 4.8 to 6 volts DC

To order, click the link below:

http://www.model-engine-plans.com/partskits/ignitionsystems/coil.htm

Allen

ahowell

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"Modelengine" Ignition Coil - fix for better spark at low RPM's
« Reply #1 on: October 16, 2010, 07:34:13 AM »
I received this e-mail from the coil's manufacturer:

"I also have had some time to play with your Tim-6 and it was doing the same thing that Bert's was. I normally check them with the little electric motor running and after attaching the wires to the coil I just hold the hall sensor up near the spinning magnets. I found, quite by accident that periodically if I held the hall to a stationary magnet and then removed it, the coil would not fire. Waving it past slowly wouldn't fire it but as soon as I spun the disk with the motor it would start sparking. I'm not sure whether I've found a solution to a problem or if a problem even existed. I'm still learning this system. Anyway, I found if I attached a 1K ohm resistor to the spark plug lead that the coil would fire every time no matter how long or how fast the hall sensor went by the magnet. I will be testing and investigating this further. I am now including a 1K carbon composition resistor with each coil and I'm sending you at least 25 spare ones. Let me know if you have had any comments, complaints, or questions concerning not firing at slow speed or during starting. I think it would also be a good idea to send a resistor or 2 to whomever did the initial coil testing and also have him retest the V-4 with the 1K resistor in the lead to the distributor. I did much testing and running on my little Upshur with no noticeable change in running. In fact I even tested it on one of the glow engines that I converted. Those engines run 10:1 compression and I run them on E-85 ethanol so I know it isn't going to lessen the spark energy. I actually think with the resistor the coil is able to sustain a much larger spark gap. I have been testing them with a minimum of 3/16" spark gap and all have shown a very steady spark."

So there you go - just add a 1K Ohm resistor to the spark plug lead for better spark at low RPM.

Allen