Characteristics of the automatic transmission speed sensor
Purpose:
Determines and transmits information about the speed of rotation of the automatic transmission output shaft to the transmission control system.
Design:
*Sensor type: Magnetic or optical
* Housing: Usually made of metal or plastic
* Reading element: Coil or LED (for magnetic and optical sensors respectively)
Working principle:
* Magnetic Sensor: Detects changes in the magnetic field generated by a rotating gear or disk.
* Optical sensor: Detects interruption of the light beam blocked by rotating blades or curtains.
Output signal:
* Analog: Voltage (usually AC) proportional to rotation speed.
* Digital: Pulses whose frequency corresponds to the rotation speed.
Performance characteristics:
* Speed measurement range: Typically 0 to several thousand revolutions per minute (rpm)
* Accuracy: Typically within 1-2% of full scale
*Immunity to interference: Must be resistant to electromagnetic and mechanical interference
* Response time: Must be fast to ensure precise control of the automatic transmission
Main advantages:
* Provides accurate information about automatic transmission rotation speed
*Used to control gear shifting and torque converter lock-up
* Helps optimize performance, fuel economy and drivetrain durability
Typical Applications:
* Automotive automatic transmissions
*Dual clutch transmissions
* CVTs (CVT)
* Engine management systems