Today was Bike Day. In the last week the new fork stanchion pipes came from Thailand and I finished the relay modules mentioned in an earlier post so we were able to make a lot of progress.
If you recall, XOR logic can be built with relays thus:
And here we have the real thing:
You'll see the 'X' shaped cross-connects between relays here, just like in the diagram:
First attempts at soldering the relays "dead bug style", i.e., with the relay placed upside down like a dead bug with it's legs in the air and soldering directly to the pins met with failure. Second attempts with my soldering pencil also met with failure because the teeny little holes were too close together and the solder balls of adjacent connections touched and shorted things. A trip to Rat Shack for a fine soldering iron tip and some teeny .022" solder made soldering a real joy as the solder went right where I wanted it and flowed like water instead of peanut butter. Ok, I'll win no awards for aesthetics but the proof is in the results, and the modules work.
You'll see above I had to make two connections to the Common legs of the center relay, so I just used a long lead and bent it over and soldered it twice on the backside.
Finally, the modules got a little protection in the form of hot glue and electrical tape. With the front end re-assembled, we reinstalled the main wiring harness and added in my modules. Some consternation was experienced when the rear turn/brake lights inexplicably malfunctioned. We checked, checked again, and rechecked our wiring and it was all correct. Based on the pattern of the light display, I suspected a faulty brake/taillight bulb, so I broke out the multimeter and started testing. Bulb was fine but the socket had some very strange results -- zero volts between either bulb contact and ground, but 5.5V between the two contacts! That's not supposed to happen. Finally we pulled the lens off and determined that the ground wire for the bulb holder had fallen off, resulting in the taillight grounding itself through the brake light and confusing the heck out of my relay module and confusing the heck out of us. Ground wire reattached, everything worked as designed. Whew!! I was starting to doubt my electrical engineering and soldering skills for a minute there.
With the day almost spent, we made it look like a real motorcycle again. Lemontree put on the mirrors, tank, and side covers. All that's left now is odds and ends -- clean the carb, adjust the front brake and lube all the cables, polish the engine, and... well, that's about it really.