6-pin SC/Turbo CDI unit repair documentation

Early_S_Man · 11:19 PM

Well, after a bit of a delay ...

Here's the schematic and replacement parts list for the Bosch 0.227.300.004 6-pin CDI unit, cussed & discussed at great length ... and used on SCs & Turbos thru '89!

Tim Polzin · 01-24-2005, 05:20 PM

Great work Warren. This is what makes this board as great as it is.

Tim

MotoSook · 01-24-2005, 05:27 PM

Excellent, Warren!

ChrisBennet · ChrisBennet's Garage

Awesome!
-Chris

randywebb · 01-24-2005, 08:21 PM

Now somebody post a circuit board pic

- That's defintiely $400 worth of parts isn't it.....

Grady Clay · 01-25-2005, 05:41 AM

Warren,

Thanks!

Here is the thread on the Bosch 3-pin. It has a wiring diagram also.
Perma-tune CD or Bosch CD?

Best,
Grady

Superman · 01-25-2005, 06:12 AM

Very cool. I just wish I understood.

Which of those parts fails, typically, when a Bosch CDI unit stops working?

jpnovak · 01-25-2005, 06:45 AM

Very Nice Warren!

Superman, I think the Thy might have the best chance of going bad. of course, there is always the chance of a blow cap, diode or resistor.

pwd72s · 01-25-2005, 09:02 AM

Quote:

Originally posted by Superman
Very cool. I just wish I understood.

Which of those parts fails, typically, when a Bosch CDI unit stops working?

Too true, Supe...we mere mortals wouldn't understand. But in the right hands, this info is valuable. I try to have the info on hand for those with the right hands.

randywebb · 01-25-2005, 09:53 AM

Component replacement and checking is not that hard on these older analog items. You could take a course at a community college and I'd bet 1 course would do it. This also helps stave off Alzheimer's if you are turning gray... If you screw it up, then send it in for re-grooving by a pro.

hobieboy · 01-25-2005, 12:06 PM

Great work Warren...

Another question - what about the pin-out for the 6 pin connector? Is there any place I can find that?

thanks...

Early_S_Man · 10:08 AM

Here is the pinout looking into the connector with the mounting flange sitting on the hand or table ...

. 31/1 ... TD ... 31d

. A . . . . 15 . . . 7

==============

31/1 -- Power ground
31d -- Signal ground [green coax shield] for trigger signal

15 -- +14 Volt power lead

7 -- Trigger signal from distributor magnetic pickup coil

TD -- Tachometer Drive signal

A -- +460 Volt pulse output to coil

Early_S_Man · 02-05-2005, 07:26 AM

Here are some resources worth reading if you are a bit rusty on the theory of operation ...

http://www.irf.com/product-info/thyristor/manual/scr_manual.pdf

http://www.st.com/stonline/books/pdf/docs/4347.pdf

http://www.st.com/stonline/books/pdf/docs/5201.pdf

Early_S_Man · 02-05-2005, 07:52 AM

And, here is an application note from RCA that may be helpful ... after much difficulty with pic uploads [never copied the image code to edit window -- multiple attempts] ...

Early_S_Man · 02-05-2005, 08:28 AM

And, here are the last two pages of AN-6288 ...

silverc4s · silverc4s's Garage

I nominate this entire thread to become a PP Tech Article. Invaluable information from Warren as always, Thanks!!!

Early_S_Man · 02-21-2005, 12:19 AM

Here is a bit of design info from GE Semiconductors Electronic Data Library #400.6 on the single-transistor inverter as used by Bosch in our CDI units:

KobaltBlau · 02-21-2005, 09:15 AM

Truly awesome. Adding to the knowledge bank, Warren!

Grady Clay · 02-21-2005, 10:27 AM

Randy,

Thyristor is an early name for a Silicon Controlled Rectifier (SCR). The name is a combination of Tryratron tube and transistor. The beauty of an SCR is that a miniscule current or pulse can turn on a huge current and it stays on until the source current drops below a certain threshold. This is used in CDI and household dimmers.

Best,
Grady

randywebb · 02-21-2005, 10:59 AM

You're right -- I was thinking of thermistor.... Dunno whether to blame it on age or elapsed time since I've done any electronics work... I'll kill that post.