Speed and distance slow to start

[ngrimm]

I haven't forgotten about the write up. I'm getting ready to test a new version of my circuit that should improve the accuracy at lower speeds.

[msc]

Apparently I was too quick to dismiss the possibility of it being a variable reluctance (inductive) sensor.

See this thread for additional discussion and other possible solutions. http://ecomodder.com/forum/showthrea...zed-16518.html

I personally like the LM2907 solution but what works best for others could mostly depend on what parts they have on hand. Additional proven solutions give people more options so please do complete your write up when you have a chance.

Mike

[ngrimm]

First off I want to thank DCB and all involved in designing the MpGuino! Sorry for the delay but I just now finished testing my new circuit to work with the inductive sensor and it works great at all speeds down to 3 mph now and outputs a pretty clean square wave. I could go lower but I was worried about spurious noise giving false triggers. I am using one channel of an lm339 quad comparator from Radio Shack configured as a zero crossing detector. I was having some annoying problems at first but it turned out my breadboard had a problem so the chip wasn't getting ground One thing I am not sure of is whether to use a pcb mounted potentiometer on it to adjust the input threshold or just use a fixed resister. By adjusting the pot I think it would work fine even when using a 5 volt hall sensor. I'll go to Radio shack and pick up a small board to solder all the parts onto and take some pics. They should have everything needed to put it together. Thank you for your patience.