[Tesseract]

Abstract: tach sensor works as advertised with the Soliton1; YMMV.

Josh from RechargeCar.com sent us his tach speed sensor to see if it was compatible with the Soliton1. I was a bit concerned that the rather weak built-in pullup resistor (2.2k) might make it susceptible to noise, but it worked perfectly right out of the box. Took all of about 2 minutes to install it on our dyno and it appears you can still mount a pulley on the motor's tailshaft with the exciter ring for the tach sensor in place.

RPM pickup was very stable and the default setup of 4 pulses per revolution greatly improved the behavior of idle on the dyno (which usually behaves poorly compared to a real car with real inertia in the transmission).

The exciter ring is made of aluminum and has steel setscrews in it to act as targets for the Hall effect sensor. I was extremely skeptical that the Hall sensor would work well in the high magnetic field environment of a DC motor, but Josh says the sensor he uses has a biasing magnet inside so it doesn't respond so much to external magnetic fields as it does to a change in permeability (the presence or absence of ferromagnetic material in front of the sensor, in other words).

The sensor does require 12V to operate (the Soliton1 supplies filtered/fused 12V at one of its terminal strip terminals) and should work with any other controller with a tach input that can accept 12V square waves at 1, 2 or 4 pulses per turn.

The Soliton1 can work with any generic industrial prox sensor, which can be purchased for much less than this gadget, but then you have to make a target for them to read, a bracket to mount them, etc. Maybe that's worth $50 to you, maybe not. All I'm saying here is that I have, in fact, tested it with the Soliton1 and it works