MembersPage/JuhaK (2005-07-08 16:27:12)

My plan is to make the RadioBoard to be real, look also VemsFrontier/Bluetooth

I got Volvo Amazon with B20.


I mounted a 36-1 toothwheel to crank from Ford (it's like [this]) and Honeywell GT101 hall sensor. I set air gap to 1.2mm, connected sensor to 9v battery and 10k pull-up resistor to output. When I manually rotate the engine dvm showed near 0v when tooth was near the sensor and 9v when no tooth, like it should. I even tried to rotate engine faster and I saw good pulsing with scope. I started the engine (currently coil trigger, v2 genboard) output was most of the time low. Frequency should have been ~600Hz idle but it was only ~60Hz or less! I tried to move sensor closer (much less than 1mm) to toothwheel and away from wheel 2mm or more. No help, signal was the same. So I moved sensor as far as about 4-5mm and it started to work! GT101 sensor specs says air gap 1.02-2.03mm. Now it's atleast double.

I did try power sensor from adjustable power supply and also tried 1k pull-up resistor. Neither did help. Sensor is mounted so when no tooth it has no metal in front of it and when tooth is front of it metal is much over sensors centerline. Sensor has built in capacitor between vcc/gnd.

Why? Should I use it like it work (~4-5mm away from triggerwheel) or what should I do?