1966-71 Transistor ingnition wiring diagram

Bullshark

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FYI, I stumbled across this transistorized ignition system schematic and thought it would be of value here.
 

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Weird assed engineering, no wonder nothing else is compatible, and the thing fails pretty often...winds up on side of the road .....

fucking PNP transistor in a pull UP circuit....nitwit WTF was on his mind???

i'ts an NPN PULL DOWN for the obvious choice.....cripe, even I can do better than that....

:crutches:
 
I dunno' there Gene, mine's been cookin' along for some 35+ years now. I agree there's some better stuff out there now, but the technology now is a little better than it was then too.. I changed over to a CD box just for the rev limiter. Still using the original pickup which is maybe 2x the size of an HEI pickup. And all the original stuff is in place. If the CD box shoots craps I can just plug the TI back in and drive on.
 
Anymore, Unless it's a simple fix without having to replace obsolete parts, the circuit board is trashed and replaced with a state of the art, solid state ignition module. That way you keep the NCRS stock configuration. I doubt even the NCRS guys tear down the module for judging.......do they:bonkers:

Bullshark
 
Anymore, Unless it's a simple fix without having to replace obsolete parts, the circuit board is trashed and replaced with a state of the art, solid state ignition module. That way you keep the NCRS stock configuration. I doubt even the NCRS guys tear down the module for judging.......do they:bonkers:

Bullshark

Mammories are made of this....

decades ago in the Tv business, the outside guy running calls was referred to as a 'flying diddlestick happy tube jockey'......

the diddle stick referred to the plastic tuning wand used for various signal circuit alignments....well some guys had a temptation to do field alignments....

technically not possible, BUT under certain circumstances you MAY be able to do some good, IF you knew WTF you were doing....

when eary Solid state TV came in, the attempt to do things 'modular' came to be....and so, we called them Module Jockey or 'Module Module Man'....

been a while....

:stirpot::lol:
 
Weird assed engineering, no wonder nothing else is compatible, and the thing fails pretty often...winds up on side of the road .....

fucking PNP transistor in a pull UP circuit....nitwit WTF was on his mind???

i'ts an NPN PULL DOWN for the obvious choice.....cripe, even I can do better than that....

:crutches:

I'm not trying to excuse or explain the designer's reasoning, but there are a couple of things of note. I do agree that a PNP is the hard way to do things, and this design was a little before my time, but I don't know if there were any high current (I'm under the impression that the primary current was 6-9 amps in this application), high voltage NPNs available at a reasonable cost at that time. The PNP was a germanium, rather than the later type silicon transistor, hence the delicate nature regarding temperature and the need to place the box in the cool area ahead of the radiator. IIRC, and please correct me if I'm wrong, the coil for this application was a special high turns ratio unit to make up for the modest flyback voltage possible with the max Vce of this transistor and diode (zener) clamp.
Just my two cents. I've never run one of these units, but I do enjoy reading and discussing the technical aspects of our cars.
 
I don't know the difference in the coils, but the TI coil carried a different part number than the standard one, and had a sticker on it that said "Transistor Ignition" or something. It was identified as being different.
 
I'm not trying to excuse or explain the designer's reasoning, but there are a couple of things of note. I do agree that a PNP is the hard way to do things, and this design was a little before my time, but I don't know if there were any high current (I'm under the impression that the primary current was 6-9 amps in this application), high voltage NPNs available at a reasonable cost at that time. The PNP was a germanium, rather than the later type silicon transistor, hence the delicate nature regarding temperature and the need to place the box in the cool area ahead of the radiator. IIRC, and please correct me if I'm wrong, the coil for this application was a special high turns ratio unit to make up for the modest flyback voltage possible with the max Vce of this transistor and diode (zener) clamp.
Just my two cents. I've never run one of these units, but I do enjoy reading and discussing the technical aspects of our cars.

HUmm the act of using a 'custom coil' for that unit when there still are not ONE but TWO series resistors, is interesting....definately a current problem....

'66....HUmm....Trying to recall, Sony came out with the KV1210 in the late 60's and it had a NPN Horiz out transistor.....forget any ratings though....surely it was silicon not geranium.....

funny in that I was checking my tach the other week and used a old Horizontal output transistor and drove it with a old audio oscillator....sparks clunking all over outta that HEI.....and the tach ran fine tracked very well with the Freq of the oscillator...it was digital and right on track according to Mr. Tektronics....

:stirpot::cool:
 
HUmm the act of using a 'custom coil' for that unit when there still are not ONE but TWO series resistors, is interesting....definately a current problem....

'66....HUmm....Trying to recall, Sony came out with the KV1210 in the late 60's and it had a NPN Horiz out transistor.....forget any ratings though....surely it was silicon not geranium.....

funny in that I was checking my tach the other week and used a old Horizontal output transistor and drove it with a old audio oscillator....sparks clunking all over outta that HEI.....and the tach ran fine tracked very well with the Freq of the oscillator...it was digital and right on track according to Mr. Tektronics....

:stirpot::cool:

I think we definitely are in agreement that the design has a few, shall we say, interesting aspects about it. :thumbs:
 
seeing how I collect worthless, useless junk anyone who has (or knows of anyone with) any factory Transistorized Ignition stuff I`m willing to buy it.....yes, actual cash money. send a PM if you have or know of anyone with any TI stuff for sale.................redvetracr
 
seeing how I collect worthless, useless junk anyone who has (or knows of anyone with) any factory Transistorized Ignition stuff I`m willing to buy it.....yes, actual cash money. send a PM if you have or know of anyone with any TI stuff for sale.................redvetracr


I have a 69 box SOMEWHERE in my shop.:idea:
 
seeing how I collect worthless, useless junk anyone who has (or knows of anyone with) any factory Transistorized Ignition stuff I`m willing to buy it.....yes, actual cash money. send a PM if you have or know of anyone with any TI stuff for sale.................redvetracr

I have a 15? y/o MSD 6 box....no rev limiter....
 
I think they have a flat rate because they don`t repair them, they just replace the board inside.....

hehe, Ya THINK, ??? that damn board has enough conformal coating on it to pass a nuclear sub test, direct immersion....

:stirpot::stirpot::lol::stirpot:
 
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