Ignition module 82 500 SL
 

Has anyone found a suitable replacement coil drive transistor for the ignition modules in the w107 SL's? The Bosch part number for the module is 0 227 100 023.

The original transistor seems to be a high powered darlington of sort with a Bosch lable on it, which would be impossible to get hold of. I have tried an MJ10012 but would have to limit the base current as it was driven to hard and died.

Limiting the drive may also effect the feedback to IC1 and effect the pulse timming, so I would prefer to find a transistor which could handle the base current supplied by IC1.

If anyone has any ideas in this or have found a suitable replacement for both the transistor and IC1 if it ever goes, please let us know.

Regards Damian

Bump, anyone ever find a replacement for the transistor?
http://www.peachparts.com/shopforum/vintage-mercedes-forum/101410-1975-450sel-request-help-get-running.html

an ST BU931T might be worth looking at. 1A base, but 5 peak. It's only in a TO-220, so I can't say how it would be thermally. It is auto-rated, though. A cross showed a TIP152, but that doesn't look good enough.

If you can crack this nut, you could probably start a tidy business.

if there is an identifier number i'd give Newark Electronics they have an 800 number. they are hugh and might be able to cross it. i get all my electronics from them for my CNC equipment. just a suggestion for a solution.

another way to go is to buy from petronics for about 70 bucks and replace all that nonsense. i will do that to save my switch cause i plan on the 72 being all original. but to merely drive it the petronics is a much stronger ignition. here they are http://www.vintageperformance.com/retrorockets/index.htm

Thanks for the replies, I posted pictures of the igntion module in the thread that is linked above.

I will be posting what I ultimately find there also.