igniter = amplifier?

[rkubik]

Just wondering, does the "igniter" box serve to electrically amplify the signal from the pickups? If so, might be an interesting bodge to make one up. Winter is long.

[catbed]

the ignitor box does not amplify the voltage. it sends voltage to the coils which connect to the spark plug. the ignition box knows when to send voltage to the coils from the ignition unit on the crankshaft. the coils convert low voltage, high current to high voltage, low current.

[Steve]

Well, I may have to defer to others that know more about that little black box, but the basic principle of the ignitor is to take the little signal that comes from the triggers on the end of the crank and AMPLIFY it enough that the coil can make a respectable spark. Whether it amplifies voltage or current is up in the air, but yes, the ignitor IS an amplifier.


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[DaveDanger]

I'll go along with catbed and say that the ignitor box is more of a timing control device, not an amplifier. The coils by definition are an amplifier or multiplier. Voltage comes into a coil (transformer) at low potential (battery voltage at best), and comes out increased to a high potential (from 20,000 to 30,000 volts - hot spark).

[Steve]

OK, then, would you believe it's a SWITCH?

The coils are just a transformer that work on the principal of utilizing a collapsing current for a one-time spike of voltage that goes to the spark plugs. The ignitor controls the flow of current to the coils, and interrupts that current when told to do so by the triggers mounted on the right side of the crank.

Now back to my original theory: somewhere in that box, I am reasonably certain that signals from the triggers are amplified enough to activate the switches that control coil current.

So...it might have an amplifier in it, but it does other stuff, too. 8-[

[SPARKSS]

Just wondering, does the "igniter" box serve to electrically amplify the signal from the pickups? If so, might be an interesting bodge to make one up. Winter is long.

Sometimes devices such as "ignitors", "ignition modules" etc are called amplifiers but an understanding of amplifier classes shows that it is in no way a linear type of amplifier such as would be used to amplify music, or radio signals for example. This type of amplifier is a controlled switch.......whereby a low voltage, low current signal controls a circuit that can switch a heavy current load.....in this case your pickup coil signals the ignitor to switch the ignition coils. The waveform of the INPUT signal....that from the pickup coils wouldn't have much resemblance to the OUTPUT switching signal controlling the ignition coils.

It SWITCHES the ignition coils ON and OFF to cause it to develop High Voltage required for the spark plugs. At the point where it switches the coil OFF, this high voltage is developed. The electromechanical RELAY would be a closer analogy.

[trippivot]

the brain box gives and cuts a connection to ground at the primary side of the big ignition coils to induce a collapse of the electric field sending it out the secondary side to the spark plugs. (magnetos work opposite=rising field)


further amplification of the spark really isn't needed as the stock coils are amplifying from 12volts@7 amps all the way up to 20,000volts+@1.5milli amps approx. and saturation time is quick enough for 10Krpm operation without misfire.

the resistor cap helps filter the 20,000volts down and actually cleans up the shaggy jolt into a controllable timed ignition event.

removing the resistor dosen't really give you any performance or easier starting. it DOES assist in creating detonation and preignition(BAD)

if you have points there are other options for a hotter spark. at the sacrifice of the contact point life span.

[duaneage]

I opened one up for a chap from Florida. NpN transistors in a Common Emitter mode. So it is a power amplifier as far as coil drive goes because the coils are 3-5 ohms. There also was a small circuit designed to shape the received signal so the coils received a proper pulse. You need to take what can be a variable signal from the pickups and shape it intoa definative on/off for the coil field to collapse properly

Coil magnetic field collapse is actually what fires the plug, the secondary transforms the collapse and steps it up a few thousand volts.

I wouldn't try to make one, there are plenty for sale cheap.

[Matchless]

The Suzuki manual mentions the NPN transistor and states that it is used as both an amplifier and switch in the Igniter Unit. At the end of the day it is just generating a nice clean and waveform pulse at a voltage required by the input side of the coils from the sinewave generated by the pickup as duanage explained.

[duaneage]

I looked into repairing these ignitors for GSR people but the parts are getting harder to find. Add to that the vast array of designs Suzuki seems to have used and it was not practical. As long as ebay has them for 20-30 dollars that is the way to go. IIRC I did get Issac's ignitor working again but it did not last, the replacement part was not up to the task.

Interesting circuit, almost like a stereo amplifier with it's two channels for each coil.

[trippivot]

silly circuits, sparks are for welders


ok here is the best I can do. Overkill you say? yep #1=pointless electronic ignition
transistor n.p.n. is #2=A.Base-takes signal from control unit. B.Collector-sends signal to coil (ground cut) C. Emitter-Ground #3 is obvious #4 is digital transistorized ignition this has the wave form arrangement circiut(amplifier in #4 not in GS ign)
tech data straight from Suzuki F.A.S.T. school pages
the igniter unit eliminates the need for contact breaker points in the circiut. It is triggered by a small current from the signal generator and provides for a very fast interruption of the primary circiut.

[Matchless]

Interesting info! As duanage says, the best bet and cheapest at the moment is a 2nd hand unit.

[duaneage]

ok here is the best I can do. Overkill you say? yep #1=pointless electronic ignition
transistor n.p.n. is #2=A.Base-takes signal from control unit. B.Collector-sends signal to coil (ground cut) C. Emitter-Ground #3 is obvious #4 is digital transistorized ignition this has the wave form arrangement circiut(amplifier in #4 not in GS ign)
tech data straight from Suzuki F.A.S.T. school pages
the igniter unit eliminates the need for contact breaker points in the circiut. It is triggered by a small current from the signal generator and provides for a very fast interruption of the primary circiut.

Diagram three is wrong, the rise time is in volts not amps. The "CPU" is a speed controlled advance unit that replaces mechanical advance. Not applicable to our bikes, we still have weights and plates. Another name for the waveshaping circuit is a gate, it can use a SCR as a barrier diode to allow pulse width modulation if required.

This circuit does not show the transistor biasing and all that stuff, I would not try to design or build from it. The transistor I found at radio shack was a TIP122 if I recall, it had around 60volts of Vcb but I don't think the current capability was enough. The transistors were heatsinked to a rather small aluminum rail inside the box. The replacements may have needed more heatsink to do the job.