ignition coil driver

[Tinbasherdan]

for the radial, i need a booster boil as the on starting the impulse mags dont generate a strong enough spark to start the engine. you can get dedicated booster coil set ups for around 100 quid, but you can also use an ignition coil off a car. now im no electrical genius, all i know is i need something to drive the ignition coil, so brains of the forum, throw me ideas!!

 

[8ob]

Get creative and fit a donkey engine on the rig to spin it up faster

Bob

 

[500e]

Are you looking for something like the "Shower of Sparks" on the Lycoming's ?
Only ever had 1 boil it sure did not need a boost

 

[Tinbasherdan]

Get creative and fit a donkey engine on the rig to spin it up faster

Bob

You can get a hand cranked booster coil, sod that though

 

[Tinbasherdan]

Are you looking for something like the Shower of sparks on the Lycomings ?

I’ve not heard them called that, but probably. The yanks call them starting vibrators (oooh er missus)

 

[500e]

Switzer\ lycoming call them that

https://www.aircraftmagnetoservice.net/typical-system-with-staring-virbrator

 

[500e]

Google
how does shower of sparks work, They also call them trembler coils

http://www.aeroelectric.com/articles/Shower-of-Sparks/ShowerOfSparks.pdf

 

[merryman]

That starting "vibrator system" seems a little like the trembler coil system used on model T Fords. Bit puzzled that your impulse mags not producing a decent spark. The whole point of "impulse" is to increase the spark for starting. I have only come across one, on a Jap donkey engine and was suitably impressed by the size of the spark it produced at the low speed of a hand cranked Jap.

 

[Tinbasherdan]

That starting "vibrator system" seems a little like the trembler coil system used on model T Fords. Bit puzzled that your impulse mags not producing a decent spark. The whole point of "impulse" is to increase the spark for starting. I have only come across one, on a Jap donkey engine and was suitably impressed by the size of the spark it produced at the low speed of a hand cranked Jap.

They can- and will eventually start on the mags alone but it’s hit and miss. I suppose they’re emptying quite a large amount of fuel into the bore and as such Need a hefty spark

 

[500e]

Used to make electric fence units out of a coil relay & capacitor, vary the cap for spark frequency

 

[Tinbasherdan]

i tell a lie, they arent impulse coupled! trying to do too many things whilst writing the post

 

[Parm]

Get creative and fit a donkey engine on the rig to spin it up faster

Bob

Trust you @8ob, I bet you’ve got at least one spare one kicking around, lol

 

[eddie49]

I think that you need something that will electronically simulate a rotating distributor cam and a contact breaker. You could start with an add-on reactive or capacitive discharge ignition driver ( CDI ignition box ), such as a Sparkrite:

https://www.ebay.co.uk/itm/Sparkrite-TX2002-electronic-ignition-system/303276317484

or a Lumenition unit:

https://www.ebay.co.uk/itm/lumenition-electronic-ignition-Rs2000-Escort-Rally/283608967465

https://www.ebay.co.uk/itm/Lumeniti...ctronic-Ignition-Kit-Car-Classic/163854073080

and then use a variable-speed oscillator to trigger it ( instead of the distributor pick-up coil or optical shutter ).

 

[HughF]

Drive the coil with a Bosch bip373 Darlington driver, trigger the circuit (google for the reference design) with a pickup on the crank at the correct point...

 

[Tinbasherdan]

Drive the coil with a Bosch bip373 Darlington driver, trigger the circuit (google for the reference design) with a pickup on the crank at the correct point...

Just needs to b triggered on a switch, on whilst starting, then flick It off

 

[eddie49]

Just needs to b triggered on a switch, on whilst starting, then flick It off

So there is no need to synchronise the spark with crank position, you just want a random "shower of sparks" ?

 

[Tinbasherdan]

So there is no need to synchronise the spark with crank position, you just want a random "shower of sparks" ?

Yes, essentially it just needs to feed a ht supply directly to the dizzy, then be turned off once the engines running on the mags

 

[Tinbasherdan]

Apologies for the poor spelling tonigh, I’m fighting my phone-screen has gone haywire

 

[eddie49]

The simple answer would be to buy the Lumenition unit, connect it to an ignition coil, and spin the optical shutter disc with a small 12v motor.
Otherwise, here is a slightly more sophisticated circuit, which uses an NE555 timer to drive a 1RF640 MOSFET to trigger an ignition coil:



This circuit was designed as a type of "electric fence" - it generates high voltage pulses continuously, as suggested by 500e.
The frequency is selected by the 100K pot, and also the actual value used for the "0.1uF" capacitor.

http://www.circuitdiagramworld.com/.../HV_Ignition_Coil_Driver_using_555_19841.html

 

[HughF]

The simple answer would be to buy the Lumenition unit, connect it to an ignition coil, and spin the optical shutter disc with a small 12v motor.
Otherwise, here is a slightly more sophisticated circuit, which uses an NE555 timer to drive a 1RF640 MOSFET to trigger an ignition coil:

View attachment 192345

This circuit was designed as a type of "electric fence" - it generates high voltage pulses continuously, as suggested by 500e.
The frequency is selected by the 100K pot, and also the actual value used for the "0.1uF" capacitor.

http://www.circuitdiagramworld.com/.../HV_Ignition_Coil_Driver_using_555_19841.html

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