'82 450 Igniter - Repair, Replace, or Make?

[bakalorz]

Ok, attaching the next schematic to try which is the combination of the German fellow's pickup setup with Martin's setup.

Thats about what I would try, although I would try it without R3 first.

[bakalorz]

Thats about what I would try, although I would try it without R3 first.

Also, one addititonal comment:

You said you have a bunch of the transistors, but didn't mention diodes ...
If you dont have any diodes handy, use the base/emitter junction of an extra transistor. just connect the base of the extra to the base of Q1, the emitter to the pickup coil, and let the collector float.

This is theoretically better than using the diode, since the idea of using the diode is just to add enough bias to compensate for the base emitter junction of Q1 anyway ... and using another similar transistor means that this will be matched better than with a diode which may have a slightly different drop.
(if you look at your figure, you'll see a teensy little diode drawn on the emitter of Q1)

Also, re-reading Lou's notes, if you connect W to 12 volts, you definately don't need R3.

[pete]

Pete, (and Martin)

I think your making this harder than it needs to be, Pete, your a computer guy down load some SPICE software and have a fiddle with these circuits, and some transistor examples, im sure in no time youll understand better.

I have used LTspice before ages ago, I down loaded a new copy tonight its come a long way. I quickly made 2 circuits, the values (componets) are nothing particular, and thats the value of a simulator, nothing goes pop and you can plug in values based on what you have at hand and work up a solution from there. ( you simply draw the circuit the software does the math) .

According to lou's notes W is a reference voltage and can be used for adjust the dwell, tying it to 12 v disables it,just leave it disconnected, don't worry about it till after you get her running.

Now I still belive all you need is a 0 heading pulse attached is how to use a opamp without a negative supply, the zeners optional it is there because I have a bad feeling about the input using 12V.(i could be wrong I there I know sweet FA about the HEI)

V1 is the 12, V2 across pickup, "out to the HEI G" B to 12v and C to the coil (-ve)


Now humour me and try the opamp idea attached...


John

You're right on my part John, I have been known to over think and over complicate things every now and then...

So the circuit attached... I assume a 741 is suitable for whatever that particular op amp is?

I have some zeners, but I need to identify them as I can't remember if I had them for 5v work or 12v work.

I definitely agree with your statement about the 0 heading signal though, that is definitely what I need.

My only question on this is in regards to getting the coil to turn on first though, and is it safe for the coil to leave it on all the time between pulses from the signal generator? Perhaps I'm not getting something here still...

I just downloaded LTSpice myself and will have a play with that also.

Now that you mention it I do recall Spice software from years ago myself, but I never actually used it, just new it was good for simulations.

Also, one addititonal comment:

You said you have a bunch of the transistors, but didn't mention diodes ...
If you dont have any diodes handy, use the base/emitter junction of an extra transistor. just connect the base of the extra to the base of Q1, the emitter to the pickup coil, and let the collector float.

This is theoretically better than using the diode, since the idea of using the diode is just to add enough bias to compensate for the base emitter junction of Q1 anyway ... and using another similar transistor means that this will be matched better than with a diode which may have a slightly different drop.
(if you look at your figure, you'll see a teensy little diode drawn on the emitter of Q1)

Also, re-reading Lou's notes, if you connect W to 12 volts, you definately don't need R3.

Yep, I have a bunch of diodes, 1N4004 from memory.

And yep, I see the diode

So, connect W to 12 volts and ommit R3... got it... although I think I will also try what John suggested and leave W disconnected and use R3 so I can see if either way is better.

Thanks again guys, I don't expect I'll get to try any of this until tomorrow night but I'll definitely let you know what I find.

[john82q]

pete
I'm thinking coil wont be on all the time, as the module controls it.
my take any way. (dwell = coil on time)

if you dont have a zener use a resister, all its doing is provideing feed back to set the amps gain.

LM471 will be fine

sent you a PM with my email respond and i will send you the ltspice file save you drawing it.

john

[pete]

Cheers John, got your PM and sent you an email.

Just waiting for some couches to be delivered so I can bust my back getting them up and down stairs (love moving furniture) so checked on here while I'm waiting.

Hopefully tomorrow night I can get stuck in and try some things.

[john82q]

LM471 will be fine

just wanted to say, no it wont, well not with tweaking, sorry if i wasted any of your time.

john

[pete]

just wanted to say, no it wont, well not with tweaking, sorry if i wasted any of your time.

john

Haha ok cool, explains why it didn't work as expected, and no probs on wasting time, didn't spend long on it at all.

I actually did get in there tonight as my wife's still a bit seedy after last night due to a few of her ex work mates coming back here after the funeral yesterday.

Anyways... I hooked the 741 up and ended up with 3.1 volts at G on the HEI module which is not what's supposed to end up there at all, was expecting more like 1.6 volts. Cranking produced no spark funnily enough...

So, I went with the revised diagram with the two transistors and the diode as the bias, but still no joy. I've attached the revised diagram.

Cranking was not giving me a nice signal on G still, so I'm not sure where I was going wrong with this one at the moment.

At this point in time, unless I can get some real daytime time to work on it when I can crank and play with the circuits, I can't see me getting any further unfortunately.

However, I'll think some more on this as I'm wondering if doing it this way requires a different hookup of the HEI module.

I do recall when being used with a distributor on a car, that W and G both connect to the distributor, and my initial testing of the HEI module was a AA battery with negative to W and positive to G to fire a spark.

I'm wondering now if I should ditch Q2, connect W to the collector of Q1, and G to the emitter of Q1 rather than the emitter going to ground (or something like that anyway).

I'll obviously need to increase the amplification for that too.

I'll try to find the diagram again that the manufacturer has of the distributor hookup.

Of course I could just be way off track here too...

[pete]

Actually, my last comment at the end there ain't gonna work at all. If what I think is right, then the collector and emitter voltages will just float somewhere near 12 volts.

I'm also tempted at the moment to ditch the whole HEI module thing and go with the German fellow's ignitor circuit.

However, I (and you guys) have already invested alot of time in the HEI modules so I should persevere... it's just frustrating (and I'm impatient).

[john82q]

Proving frustrating...aye..

At this point in time, unless I can get some real daytime time to work on it when I can crank and play with the circuits, I can't see me getting any further unfortunately.

may be you will need to make a test rig, either something you can spin or a quiet motor, with the pickups off the bike. I can see the testing being quite time consuming.

Your welcome to come around tomorrow arvo and we can knock something up if you like. (i have the means)

john

[pete]

Proving frustrating...aye..

may be you will need to make a test rig, either something you can spin or a quiet motor, with the pickups off the bike. I can see the testing being quite time consuming.

Your welcome to come around tomorrow arvo and we can knock something up if you like. (i have the means)

john

A test rig would be great but I definitely don't have the means myself at the moment.

This avo's out unfortunately, need to go into the city to do a couple of things.

However, if you're still free and willing next weekend, then I should be able to organise something.

Thanks for the offer of help again too, greatly appreciated. I'm also more than happy to repay in beverages of your choice as well...

[pete]

I got some action!!!!!

John, I tried your updated 741 circuit to no avail, and in case my signal readings were wrong in that I do get negative as well as positive signals, I tried both variations.

Then, I got so frustrated I just went bugger it and back to the beginning...

I know that when I put a AA battery's negative to W and positive to G, when I let it go it gives me a nice fat juicy spark.

I also know that the stock ignitor sparks with a positive going signal.

I also want dwell to be controlled by the pickup coils, rather than having to stuff around with biasing the HEI module if I can avoid it (I want simple stuff).

So, working with 0.08v as my input, I decided the most simplest and straight forward way is to go back to the original suggestion of a simple transistor circuit to both amplify and invert the signal.

I played around with LTSpice (thanks again for the heads up on that one John) and used the diode coupling from the German fellow's ignitor circuit to couple the pickup coil to the BC547.

I played around with random resistor values (I won't pretend to know what I'm doing here) and ended up with the attached circuit.

LTSpice showed me an inverting signal dropping from 12v to ground which is definitely right for firing the HEI module and avoiding any ambiguity.

I hooked it up on the breadboard for both pickups and coils, and just cranking by hand quickly enough fires a spark every single time as it should.

So, my question is... even though it appears to work correctly in terms of sparking every revolution, what are the drawbacks of this? Any clues?

If the amplitude of the signal increases with RPM's (which I expect it will), will that have any detrimental effects? I increased it to 1v in LTSpice and it looked ok, but of course it's hard to tell.

I will say this much though... geez it feels good to give it a crank just by hand and see those nice big blue sparks

[john82q]

well done Pete.

At least your ambition hasn't exceed your ability! (thats gotta be an all time quote from casey)


Will be interested to know, I see this time you've grounded W, does it make any difference if its disconnected?

john

[Matchless]

Pete,
I have been following your progress and just want to say: "Excellent job"!

The main test will be when running at idle and high RPM's and using the bikes battery which fluctuates at varying RPM's.

The sparking on every revolution should be no problem at all, as that is what the OEM and the German schematic does as well.

Well done!

[pete]

well done Pete.

At least your ambition hasn't exceed your ability! (thats gotta be an all time quote from casey)


Will be interested to know, I see this time you've grounded W, does it make any difference if its disconnected?

john

Cheers John! A very happy man is I. As for exceeding my ability, well, that remains to be seen yet, but I certainly couldn't have gotten where I am without yours (and others) assistance.

The proof is in the pudding as they say, and hopefully this Saturday can be first start day...

I'll test with W disconnected tonight or tomorrow night and see what the difference is (if any).

Also, if you're referring to Casey Stoner, then say no more! I taped the GP last night as Barry wasn't up to staying awake for it and I wanted to keep going on the bike, so I'll try to avoid all the news today and watch it tonight.

Pete,
I have been following your progress and just want to say: "Excellent job"!

The main test will be when running at idle and high RPM's and using the bikes battery which fluctuates at varying RPM's.

The sparking on every revolution should be no problem at all, as that is what the OEM and the German schematic does as well.

Well done!

Cheers Matchless, but I take no credit.

If it wasn't for you guys and especially Martin and John, then I'd still be scratching my head and contemplating spending a lot of money on a Boyer Bransden or Dyna S.

I'll need to check the timing yet and definitely need to see what it's doing throughout the rev range.

[pete]

Very nice Pete. Now this is getting interesting. You have spark.

Both FC and me have been working on the GS450, trying to get it to spark. It has been confirmed that the igniter is the problem. We have another 30 year old igniter on our way hoping that it will work. But I have a feeling that it will not. If that fails, we will have to try using these GM HEI modules. Neither of us are good with electronics though. I will have to read over this whole thread again. Keep going!

Well, I'm having reserved celebrations at the moment... I need to actually get the engine running and revving first to see if it works properly or not, and I have a few more tests to do as well, so I wouldn't recommend building one based on this thread just yet

But don't worry, once I know the deal, a proper build write up will be done and I will ask BassCliff to see if he's willing to pop it up with the rest of his stuff. If it works like it is, there'll be a whole 4 components per module with a total of 9 soldered connections per module, so it won't be hugely difficult as long as you can follow instructions and probably use some imagination.