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Looking for transistor data: ETD41-035
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torch:
Short story: I'm looking for a datasheet for an ETD41-035, which I believe was manufactured by Fujitsu back in the 70's and 80's. I think it might be a Darlington and know it is an NPN in a TO-220 case.

Long story: These were used in a number of Yamaha motorcycle Transistor Controlled Igniters.   The ignition system supplies a constant 12v to the coils and the TCI provides a ground path through these transistors to fire the coil based on a signal from the respective magnetic pickup. There are 2 coils and therefore 2 transistors per TCI, firing on opposite strokes.

The TCIs are generally pretty reliable (biggest headache with these TCI units is cold solder joints). However, I am trying to repair one with a considerable mis-match between the two transistors. I cannot find any data about these on-line.

According to this Chinese vendor (http://www.aliexpress.com/store/product/ETD41-035-TRANSISTOR/107262_1098158355.html) the manufacturer is "YXS Technologies Inc.":


But while the photo is identical to the Yamaha TCI  component the vendor is calling it a voltage regulator! So I can't say that I trust any info from that vendor, and YXS seems to make cables, not semiconductors, so I suspect that this is one of those infamous Chinese re-labelled forgeries.

Some people report that they have successfully used a MJE5740 as a drop-in replacement in a similar TCI. So I tried a pair of those but with less than satisfactory results. I get a very weak spark compared to a known good TCI.

I back-probed the coil grounds on a running bike. Here is the signal from the known good TCI:



Note the wide pulse after the negative spike.

Now here is the "repaired" TCI swapped into the same bike:



The negative spike is gone and the positive pulse is virtually a spike, so the coil isn't fully discharging. 

Now I just need to figure out if it's the transistors, or something else in the circuit. FWIW, both halves of each TCI behave identically. I already replaced all the electrolytic caps, measured the resistances of all the discrete resistors and tested the 8.2v zener diode. There is a mystery IC with a daughter board full of laser-cut resistors on one side and SMD devices on the underside, but I think that just controls the timing advance curve, which is working properly.

JimRemington:
The logo on the package is pretty distinctive and it may be quite helpful if you can find a match. There are a number of IC logo image collections (with respective manufacturers) on line, (e.g. http://www.electronicspoint.com/resources/logos-for-electronic-component-manufacturers.47/ ) -- looks like Fujitsu.
torch:
Yeah, thanks for the confirmation.

Anyone have a book of old Fujitsu datasheets lying around gathering dust in the basement?
Zarhi:
See if that helps: http://www.jetav8r.com/Vision/TCIRebuild/TCI_Rebuild.html
wraper:

--- Quote from: torch on July 27, 2015, 03:37:23 pm ---But while the photo is identical to the Yamaha TCI  component the vendor is calling it a voltage regulator! So I can't say that I trust any info from that vendor, and YXS seems to make cables, not semiconductors, so I suspect that this is one of those infamous Chinese re-labelled forgeries.

--- End quote ---
YXS is their store name. It's not uncommon on aliexpress that instead of brand, sellers just put their store name. This have nothing to do with the part being genuine or not.
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