Modifying to Torque Sensing

JohnD135

Pedelecer
Aug 24, 2020
61
2
Thanks saneagle. Throttle now functions as expected and I get rotation of the rear wheel. Now looking at the feed to the PAS. I assumed it would be a reed switch but i am measuring 5 volts wrt to the other two pins and also slightly negative. What is the device please? I had no idea that Hall effect detectors were so linear. 1% or so.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
21,504
8,781
62
West Sx RH
PAS is also Hall effect.
The pulses between 5v and Signal to activate movement as the magnet disc passes the Hall Sensor.
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
8,816
3,956
Telford
Thanks saneagle. Throttle now functions as expected and I get rotation of the rear wheel. Now looking at the feed to the PAS. I assumed it would be a reed switch but i am measuring 5 volts wrt to the other two pins and also slightly negative. What is the device please? I had no idea that Hall effect detectors were so linear. 1% or so.
There are two types of hall sensors: Bi-polar ones (SS41)are on/off 5v and switch when a magnet passes. They're typically used as positional or rotation sensors. Linear hall sensors (SS49) give a 1.2v to 3.8v variable output depending on the strength and orientation of the magnetic field. They're typically used for throttles.
 

harrys

Esteemed Pedelecer
Dec 1, 2016
402
108
74
Chicago, USA
This is a typical Hall sensor throttle. Just a 3 pin IC that faces the magnet bar.throttle_1.jpg

Close up of the magnetic sensor chip. It gets ground, power and puts out a varying DC signal between 0.7 V and around 4.3V.

One potential fail is if the ground wire breaks, the signal goes up to 4.3V and the controller thinks you want full throttle. Happened to me twice, but on bikes that had small motors, so I didn't realize the throttle was on til I started coasting.

throttle_2.jpg
 

JohnD135

Pedelecer
Aug 24, 2020
61
2
Thanks All, the bike is now functioning properly and i have had a four hour run today with no issues. The drive is a little quieter what with it being a sine drive and I cannot detect the controller heating up. Thanks again everyone.
 
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