TCI Replacement 2020 It Works

Jim is on the right track with doing what Yamaha did to convert the 650 to breakerless ignition. The neo magnet can be sensed much further away from the pickup coil. From what I’ve seen on the simulator the steel screws will not be a factor . Turns out the pickup we choose to try is a Yamaha repop. I thought it was from a Honda.

From wikipedia ( slightly edited) The Neo magnetic energy value is about 18 times greater than "ordinary" ferrite ... Classical powder metallurgy or sintered magnet process.
 
I'm gona hate this, but I think were on the wrong track. Sorry for the long post but...
The common types of pickup systems we have today are: magnetic, "Hall" effect, optical, and "ECKO". More or less In order of today's usage.

It seems our XS ignition system is a ECKO, "Eddy Current Killed Oscillator" system. The pickup uses two coils of wire wrapped around iron cores that has current flowing through them all the time. The sensor detects current disruption when a magnet passes near by. Pickup uses three wires, power, ground and signal.) Induction ignition, (TCI=Transistor Controlled Ignition) where the signal wire GN/W, relays a signal to a transistor ( SCR fast switching) when the pickup coils senses a current disruption. In this system the coil/s are also powdered at all times. The coil field collapses and fires the plug. So the magnet is not inducing a current in the pickup coil but instead, the TCI is watching the disruption of current it's providing to the pickup when the magnet passes. That also explains why the copper is around the magnet. The magnet's field is isolated from the rotors field and in this way provides a clean signal for disruption of current in the pickup as the magnet passes. ( I'd like to know the Ohms out the pickup on the orange/white and black/white wires.) And mention was made earlier about the coil/s to use. Induction ignition uses higher resistance coils compared to CDI systems that can use lower resistance coils. So we can't use low resistance type coil in an "induction" ignition (TCI) system unless it is specifically designed for that. The low resistance coil will flow more current thru the TCI. It will work for awhile, but eventually burn out the TCI module. I think the coil mentioned above, was in the 3 ohm range? Anyway, I think TJ used his XS pickup to fire Gonzo? If so, Gonzo is a TCI type and will work for someone just needing a TCI box and using their old pickup. ( Even if Gonzo works, if the old TCI pickup dies, soon it will be hell finding one of those. I'm very interested in the type pickup Gonzo uses, 250 Suzuki? I hope it's TCI and can be adapted to the XS.
The magnetic pickup, on the other hand, has to have a reluctor or vane to interupt it and make it work. That might be a trick to add. If your going to make a whole system, pickup and box, then you could put together a complete CDI system. CDI would work but it will be best to match the pickup and the CDI unit .

I'm looking into info on Gonzo's pickup to see if it's TCI. ( which should be the case since TJ got it to fire using his old pickup, or dragging a magnet across it.)
Oh, Man, The distance between the stock pickup coils will make a difference on where Gonzo thinks the advance should start and stop. Guess I have some more studying to do.

EDIT: Gonzo is a CDI unit. Figures.
 
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I have tried several types of pickup coils and all have worked for both DCCDI and TCI boxes I have tried. The wave forms on the oscilloscope have all looked the same.

Stock Yamaha TCI magnet and pickup coil

With the scope hooked up to just the idle coil and common on the pickup when the magnet passes it creates a pulse that is a sine wave that goes positive and then negative. This is with nothing connected to the pickup except the scope. The waveform with it hooked up to the gonzo box is the same. I see no bias voltage on the pickup.

The gonzo box fires just fine on a stock 81 TCI rotor and pickup coil wiring and a virago dual output TCI coil.

The discussion here has been more about converting non TCI rotors and stators to be just like a stock TCI pickup on the engine. The pickup we are experimenting with is a two connection coil that only contains a coil of wire on a armature. Gn250 pickup works just like this one.
 
It seems our XS ignition system is a ECKO, "Eddy Current Killed Oscillator" system. The pickup uses two coils of wire wrapped around iron cores that has current flowing through them all the time. The sensor detects current disruption when a magnet passes near by. Pickup uses three wires, power, ground and signal.) Induction ignition, (TCI=Transistor Controlled Ignition) where the signal wire GN/W, relays a signal to a transistor ( SCR fast switching) when the pickup coils senses a current disruption. In this system the coil/s are also powdered at all times.
No, on the XS TCI pickup, 1 wire is ground. the other 2 wires go to transistors. 2 separate transistors... one for retard and one for advance. When the magnet passes each coil, the small current produced is applied to the transistor base, turning them on (each in turn) until the magnet passes. That sends a pulse "count" out the emitter(s) to the IC chip.
 
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Just came across this.
3 ohm coils are the bare minimum. The closer to 5 the better.
Screen Shot 2020-05-25 at 8.11.34 PM.png
 
Stock TCI specs

'80 to 81- Measure between black/white and the white/red leads and between black/white and white/green leads Both should measure 550-850 ohms


'82 to '83. Measure between grey and black leads and between orange and black leads. Both should measure 630-770 ohms.
 
More rain and storms tomorrow. Weatherman say a better than even chance of severe weather so....
I need to pull the cover off so I can use a degree wheel to put some marks on the stator and see where we're at advance-wise.... but it looked like a full 20-25° to me. Once I'm happy it's not over advancing, I'll put some miles on it and let you guys know how it behaves.
Btw Jack, using the TCI trigger, it was definitely polarity sensitive. Connected it to what I thought was the retard sensor and it looked good dry firing it, but as soon as it started it would jump to full advance and stay there. Reversed polarity and that's what you see on the video.
 
Jim
Thanks for your leap of faith in testing this.
No worries Jack. After reading all your research in your Old Brown thread I was pretty sure you were on the right track. Hell... for 15 bucks it was definitely worth a shot. :rolleyes:
As far as an upgraded iggy for the older engines.... I think I'll turn one of my spare engines into a test stand and do the development work on that.
 
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