Buggies Gone Wild Golf Cart Forum - View Single Post - Looking for low accurate low MPH speedometer

JohnnieB · 08-06-2019, 12:29 PM

If you are using a sepex drive cart with a speed sensor on the motor, you can use the motor RPM pulses to drive a tachometer and convert motor RPM to MPH, but with a series drive, you're limited to putting magnets on one of the cart's wheels and counting the pulse.

An inexpensive bicycle speedometer probably wouldn't be very accurate in the 2-3 MPH range since one magnet attached to a wheel with an 18" tall tire on it would put out less than 1 pulse per second at 3MPH, however if more magnets were attached to the wheel, the pulse rate would be higher. For example, if 10 magnets were spaced equidistantly on the wheel, the speedometer would be receiving 561 pulses per minute or 9.35 pulses per second, which should produce a stable speed reading. Of course, the indicated speed would have to be divided by 10.

08-06-2019, 12:29 PM	#3
JohnnieB Techno-Nerd Join Date: Jun 2011 Location: West Virginia Posts: 19,654	Re: Looking for low accurate low MPH speedometer If you are using a sepex drive cart with a speed sensor on the motor, you can use the motor RPM pulses to drive a tachometer and convert motor RPM to MPH, but with a series drive, you're limited to putting magnets on one of the cart's wheels and counting the pulse. An inexpensive bicycle speedometer probably wouldn't be very accurate in the 2-3 MPH range since one magnet attached to a wheel with an 18" tall tire on it would put out less than 1 pulse per second at 3MPH, however if more magnets were attached to the wheel, the pulse rate would be higher. For example, if 10 magnets were spaced equidistantly on the wheel, the speedometer would be receiving 561 pulses per minute or 9.35 pulses per second, which should produce a stable speed reading. Of course, the indicated speed would have to be divided by 10.