Service manual

11
Currie Technologies // Service Manual (Version 2008a)
Crankset with
PTS Torque Sensor
TORQUE SENSORS
Electric bicycles with this system have no throttle. They must
be pedaled like a normal bicycle in order to engage the motor
drive system.
PTS (Pedal Torque Sensor)
Electric bicycles with this system have no throttle. They must
be pedaled like a normal bicycle in order to engage the motor
drive system.
Begin by fi rst riding the bicycle normally as if it were not an
electric bicycle. Naturally as you accelerate and push harder on
the pedals, the motor system will increase its force to help you.
If you are ascending a hill and pushing the pedals hard, the
motor will assist you by pushing proportionately with your
pedaling force. If you are descending a hill and putting very
little force on the pedals, the motor will also not be pushing very
much.
The PTS sensor works by measuring the defl ection of the
crankset under pedaling load. There are several magnets inline
inside the crankset held in place with springs. When torque is
applied to the crankset the magnets move slightly. The sensor
measures this slight movement and calculates that as torque.
Also as you pedal, the magnets spin, and this is measured as
cadence (RPM). All this information is gathered by the sensor
and fed into the controller to be analyzed and output power
impulse bursts are sent to the motor.
TMM4 (Frame Torque Sensor)
Electric bicycles with this system have no throttle. They must
be pedaled like a normal bicycle in order to engage the motor
drive system.
Begin by fi rst riding the bicycle normally as if it were not an
electric bicycle. Naturally as you accelerate and push harder on
the pedals, the motor system will increase its force to help you.
If you are ascending a hill and pushing the pedals hard, the
motor will assist you by pushing proportionately with your
pedaling force. If you are descending a hill and putting very
little force on the pedals, the motor will also not be pushing very
much.
The TMM4 sensor works by measuring the defl ection between
the frame and right side dropout. The sensor measures this
slight defl ection and calculates that as torque.
This torque value is fed into the controller to be analyzed and
output power impulse bursts are sent to the motor.
TMM4 Sensor