View Single Post
Old 06-11-2010, 09:26 PM   #21 (permalink)
usergone
I have to start over?
 
Join Date: May 2010
Posts: 214

Big inefficient truck - '94 Dodge Ram 2500
90 day: 12.1 mpg (US)

Honda Civic - '84 Honda Civic DX Hatchback
Thanks: 2
Thanked 8 Times in 7 Posts
I didn't have a coil of wire for those. I used a magnetic reed switch. The north pole would pass by the switch, and close it. Then the north pole got far away enough for the switch to open. A short amount of time would pass, then the south pole would do the same thing. The magnet would then completely rotate around the driveshaft, and come back to do the same thing.

I didn't capture that, I drew it. I rolled the truck very slowly to hear what was happening, at a rate that I could distinguish the two pulses (I had a speaker hooked up to 12v through the switch).


My next try is going to be a "bead" of glue on the back of the speedometer (the part that spins with the wheels). When the bead rolls around, it pushes on the lever of a micro switch. I think it spins slowly enough that it should work.

  Reply With Quote