It's "criticism".

 

Look, if you're saying there's some sort of amplification of the DC pulse from the pickup to control the transistor then you may be right. I honestly have no idea.

This however is utter crap (either that or you didn't explain yourself very well):

There is no amplification of any "pulse" to control the ignition coil. The only job of the ignitor in relation to the coil is to switch off the primary circuit by interrupting it's current path to ground. That's how any Kettering ignition system works whether it's done by contact points or by electronics.

 

I think what he's saying is that a transistor, by definition, is an amplifier.


However, Wankelguy, it would seem that in this situation only the switching property is being used.

Although, if that were the case, it could explain the price of igniters. (I'm not sure that a simple electronic switch would make them so expensive)

There's an easy way to find out--- With a Voltmeter =)


Just my .02

 

Not all ignitors are expensive. You can get GM and other manufacturers ignition modules that do the same thing and are way cheaper. Unfortunately they only work with the 80 model electronic ignition where the ignitors are mounted remote from the dizzy.

 

HAH! I got an 80 dizzy, hahaha!


This first gen forum is becoming more like a second gen forum.... where most people are grumpy... I think the mods hardley check here anymore cause they think were big boys and can solve things ourselves..... I think they may be right...



how 'bout dem' bran muffins?

 

I'm done with J-109 ignitors. My next ignition projects will use GM ignitors for Leading to give me a spare incase the stock Trailing ever burns out.

 

You're right, I didn't explain myself very well. I have a habit of trying to put things in simple terms for the sake of brevity and comprehension by people who are not electronic technicians (as I am). However, an amplifier is defined as a device which uses a small input to affect a larger change in output, whether it's configured as a simple transistor switch or not. It still has to be "signal biased" so that the transistor turns on when the voltage spike from the pickup is applied to the base as there is a .7V drop between the base and emitter. Hell, I'm not the one who coined the term "amplifier" with regard to the ignitors, anyway, so don't rake me over the coals about my use of that term. 'Nuff said. And the reason that the Mazda ignitors are so expensive is mostly just price gouging. I bought one new from a Mazda dealer (for my '80 Courier) in about 1983 and the thing was over $100 back then, and was still cheaper than the identical unit sold by Ford! FWIW, I've gotten several ignitors from junkyards and never found a bad one yet. You want to pull them off a car that was wrecked as opposed to rusted and neglected as that indicates that the car was at least running when it got munched, therefore the ignitors were probably working properly.

 

Yeah, what he said.

As far as I can tell, the voltage spike from the pickup can vary in intensity and frequency and all that jazz, but it doesn't affect the output of the ignitor's transistor in a negative way. The only thing that gets worse as RPM rises is the saturation of the coils. They spark less powerfully at higher RPM because there is less time to build up enough... er, juice.

All I know is the ignition stuff I'm spending my hard earned money and time on is still ok at the highest RPM my engines can rev to, so I still sleep well at night.

 

Thanks for the explanation, you obviously know more about this **** than I do (being an electronics technician and all ). But the explanation you gave earlier would only confuse someone who has no clue.

 

Interesting thread. Just wanted to mention this (repeating, to an extent, what Wankleguy said)...
But...there is amplification involved. If the only job of the ignitor was to switch off the current to the primary circuit, they could have used a relay. Problem is, the relay coil could not be triggered by the very small induced current from the reluctor (the pulse). A transistor can sense the small current from the reluctor and react by varying a larger current: by any definition, that's amplification. Just like an audio amplifier, but without the tunes...

But I do see your point, in that the ignitor is simply triggered by the distributor signal and not "amplifying" the ignition coil signal (current) in any way. The turns ratio in the coil does that, as you've said.

In the end, I'd say both you and Wankleguy (and Jeff20B) are right. The ignitor performs both functions: amplification and switching.

It's off topic, but I want your car. Badly. Mind if I drop by one day and have a drive?

-John.

 

Yeah, I understand what you guys are saying. I didn't really think of it in the sense of amplification because it's indirect. As for using a relay, that would impossible anyway because it wouldn't be able to perform fast enough.

If you wanna have a drive you're welcome to come over and visit any time.

 

Quite right. The relay was an example as to why the transistor (ignitor) works, and other options don't.

Why, thanks! Wish to Hell I could. (Now, if you could throw in a meeting with Goldie from Water Rats, I just may swim on down...)

-John.