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DIY electronic ignition - v8

Thread starter #1
Hi guys! first post here!

Im endeavoring on a little attempt to make my own electronic ignition.. I have found some interesting info online - one in particular is this one:

http://thebitwiserebellion.com/blog/2013/05/30/diy-electronic-ignition-conversion/

A similar system is seen running here:


Here is the chip that was burned out - I managed to get the plastic resin off ok -

Can anyone try help identify a replacement? I tried reading the last 2 numbers, Either 6 or G and B/P..



I have a pertronix unit that was given to me and it was burned out. Being the fellow I am I opened it up and found a very similar looking system inside. This guy built his for $10..

Here is his schematic:



I have all the hardware (magnetic wheel) and its made for my distributor - all I need is to make a little device like in the video to pickup the magnets flying past -

Has anyone done this? And can you shed some light? Am I correct that what is done in the video is what will happen inside the distributor except it will be triggered by the pickup coil instead?
 
Last edited:

debe

Active Member
#3
One of the problems with that simple circuit, is some times the unit may be energising the coil when the engine stops. This depends on where the magnet happens to stop, this could well burnout the switching IGBT. Comercial Hall drive systems have a current sensing circuit that limits the current draw if this happens.
 

debe

Active Member
#4
This Ford Distributor Module is designed for a Hall sensor, & it has the current limiting built in. I pick these up for free from a local scrap merchant before he crushes the car. Probably quite cheep where you are. They do need to be mounted on a heat sink. FORD TFI MODULE.JPG
 
Thread starter #6
Thanks everyone for the awesome replies! I forgot to mention that apart from knowing a diode is directional and to use the soldering iron when its hot - all this elec stuff is like rabbit fur in my brain! So VERY grateful for helping me with this project!

One of the problems with that simple circuit, is some times the unit may be energising the coil when the engine stops. This depends on where the magnet happens to stop, this could well burnout the switching IGBT. Comercial Hall drive systems have a current sensing circuit that limits the current draw if this happens.
Hi yes I believe that was the problem with the first version of this unit - if you left the key on it would fry the unit (probably what happened to this one). Im very conscious of this as Ive been driving old cars my whole life :)

I am trying to fit this inside my distributor and have less stuff on the outside.. This is going on our 24ft searay - Since Ihave a marine distributor (that is brand new and has a 3 degree difference in the lobes on cyl 1 and 6) im trying to fix this unit I got given.
 
Thread starter #7

Hi - so I need to replace the unit you listed in place of mine? Is is also possible to simplify the schematic with less components (smaller size)?

Thanks!

I have NO idea what component to be looking for! Hardly understand the terminology.
 
Thread starter #8
Another issue - the desired dwell on a v8 is usually in the 26-34 range for regular coils.. Im not sure how pertronix achieved this with this unit, possibly the distance to the sensor or perhaps some other kind of trickery?

Getting spark is one thing - but id be curious to know how one would go about trying to achieve dwell using the hall methods..

Also - here is a similar pic of the reluctor I have, can anyone tell me what type this is (so I can at least correct my terminology!) and if it will work with the components / schematic above?



I held a metal knife onto mine and it doesnt appear to be magnetic - how does this trigger the sensor?
 

ClydeCrashKop

Well-Known Member
#9
When discussing an ignition system, dwell refers to the length of time--read in distributor cam [shaft] rotational degrees--that the breakers were closed and the ignition coil was being charged with electricity. The coil fires (sends voltage to the spark plugs) just as the breakers crack open and the dwell period ends.

It is irrelevant and not adjustable on electronic ignitions.
 
Thread starter #10
Thanks clyde - had no idea this doesnt apply to elec ignition. In my stoneage way of thinking does the coil NOT require this power build up then? I would imagine it still requires dwell or does it just fire off the single spark signal?

excuse my lack of knowledge on these parts. Im very familiar with points - been changing them out for years, setting dwell/etc -
 

alec_t

Well-Known Member
Most Helpful Member
#11
it doesnt appear to be magnetic - how does this trigger the sensor?
The sensor includes, or is magnetically close to, a permanent magnet. The reluctor completes or modifies the magnetic circuit.
 

debe

Active Member
#14
If you ae going to build it to fit in the distributor, be aware that the switching IGBT will require a heat sink of some sort.
 
Thread starter #15
Clyde - link not working.. chmod it :)

debe - thanks, for now im replacing the unit on my broken one, it seems it does attach to the distributor body which is aluminium so has a big one right there, about 4" wide - only thing is engine heat soak into it as well..
 
Thread starter #17
Mine is a pertronix ignitor 1 unit that burned out.. I foud a replacement chip on ebay for $4.. will pop it on and see what happens lol.. but no oil on this thing.. just the reluctor and the chip thing i ordered.. underneath are some more components but its TINY.. about 5cm x 2cm x 1cm thick..
 

debe

Active Member
#18
This is how most electronic distributers use Hall sensors to trigger Ign modules. These are hall sensors designed for automotive use & have built in magnets & are quite HALL.1.JPG HALL.2.JPG HALL.3.JPG rugged.
 

debe

Active Member
#20
If your setup doesn't work with the reluctor. You could try this Bosch ign module that's designed for that system. Just find a sensing coil from a scrap distributor & fit to your distributor. You should be able to find the Bosch module at a wreckers cheep All of these parts I have scrounged from scrap places for free. RELUCTOR IGN.1.JPG RELUCTOR IGN.2.JPG RELUCTOR IGN.3.JPG
 

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