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Glory be! My first resurrection.
A few months ago, one of the members sold me a TCI and when it got here, it would not fire one of the coils. Being an honest fellow, he returned my money and told me to throw it away.
I have a hard time throwing things away, so it sat there. Until I decided to see if I could figure out what was wrong.
After trying the re soldering that Davinci recommends, and not having any success, I took the board out of the case and started investigating.
There were no signs of burnt or broken components, and the solder joints all looked good, so it was apparent that there would have to be a more "in depth" method used for trouble shooting.
Using a DC motor, (which had to have the brush leads reversed so as to rotate in the right direction), I mounted a set of pickup coils and the reluctor on the shaft end, and wires leading to the 4 conductor plug that goes in the TCI.
A 2-pack of burglar alarm batteries supplies 12.5 +/- volts to a switch that supplies power to the TCI and two 1156 bulbs that show about three ohms resistance to the TCI. I added a 1 ohm resister to cut down the heat produded by the bulbs, but feel that the load is about what the coils would supply. (In the original bread boarding, I used both coils and the spark plugs hose clamped together, but it was a little cumbersome). All of the stuff is now housed in an ammo can, which weighs about what a ammo can full of ammo weighs.
Power in and coil power out were wired to the 8 prong TCI plug.
Two switches are used to imitate a broken pickup wire to each coil.
I took my good TCI, and hooked it up and took scope pictures of the signals of the string of transistors that power each coil circuit.
After getting a base reading of traces, I took voltage readings at the base and collector terminals of the transistors.
Replacing the good TCI with the defective one, and checking the progression of the pickup coil signals through the circuits, I found an anomaly in transistor Q3.
I un soldered it, and soldered in a substitute that does not have the same pin out, but has about the same characteristics as the original. (Some guess work done there. The replacement transister looks like it has to piss, standing there with it's legs crossed.
).
Plugged the TCI back in, turned on the test rig, and hot snot, it works!
Now, I just have to wait until the replacement transistors get here, after their trip on a slow boat from China. I can then resolder the board into the case and use it.
Still have to figure out how the timeout circuit works, the one that shuts the coil output off after 5 seconds when there is no input from the pickup coils. I'll investigate that tomorrow.
I'm a happy camper.
Now, what would be nice, is an electrical guy that can look at the schematic and tell me how this thing works.
I'll try this "heysuse" TCI on my bike in a day or two, just to make sure that my test rig gives me good readings. (I need to re-sync the carbs anyway)
Yahoo! IT LIVES, IT LIVES.
CZ
A few months ago, one of the members sold me a TCI and when it got here, it would not fire one of the coils. Being an honest fellow, he returned my money and told me to throw it away.
I have a hard time throwing things away, so it sat there. Until I decided to see if I could figure out what was wrong.
After trying the re soldering that Davinci recommends, and not having any success, I took the board out of the case and started investigating.
There were no signs of burnt or broken components, and the solder joints all looked good, so it was apparent that there would have to be a more "in depth" method used for trouble shooting.
Using a DC motor, (which had to have the brush leads reversed so as to rotate in the right direction), I mounted a set of pickup coils and the reluctor on the shaft end, and wires leading to the 4 conductor plug that goes in the TCI.
A 2-pack of burglar alarm batteries supplies 12.5 +/- volts to a switch that supplies power to the TCI and two 1156 bulbs that show about three ohms resistance to the TCI. I added a 1 ohm resister to cut down the heat produded by the bulbs, but feel that the load is about what the coils would supply. (In the original bread boarding, I used both coils and the spark plugs hose clamped together, but it was a little cumbersome). All of the stuff is now housed in an ammo can, which weighs about what a ammo can full of ammo weighs.
Power in and coil power out were wired to the 8 prong TCI plug.
Two switches are used to imitate a broken pickup wire to each coil.
I took my good TCI, and hooked it up and took scope pictures of the signals of the string of transistors that power each coil circuit.
After getting a base reading of traces, I took voltage readings at the base and collector terminals of the transistors.
Replacing the good TCI with the defective one, and checking the progression of the pickup coil signals through the circuits, I found an anomaly in transistor Q3.
I un soldered it, and soldered in a substitute that does not have the same pin out, but has about the same characteristics as the original. (Some guess work done there. The replacement transister looks like it has to piss, standing there with it's legs crossed.
).Plugged the TCI back in, turned on the test rig, and hot snot, it works!
Now, I just have to wait until the replacement transistors get here, after their trip on a slow boat from China. I can then resolder the board into the case and use it.
Still have to figure out how the timeout circuit works, the one that shuts the coil output off after 5 seconds when there is no input from the pickup coils. I'll investigate that tomorrow.
I'm a happy camper.
Now, what would be nice, is an electrical guy that can look at the schematic and tell me how this thing works.
I'll try this "heysuse" TCI on my bike in a day or two, just to make sure that my test rig gives me good readings. (I need to re-sync the carbs anyway)
Yahoo! IT LIVES, IT LIVES.
CZ
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