The SS41H / SS41 is a bipolar digital Hall-effect sensor commonly used in brushless DC motors and speed detection.
1. Standard 3-Pin SIP Package (TO-92 Style)When holding the sensor with the leads pointing down and the branded, flat front face looking at you, the pinout from left to right is:
Pin 1 - VDD - Supply Voltage - Connect to +4.5 V to +24 VDC
Pin 2 - GND - Ground - Connect to the system ground (0 V)
Pin 3 - OUT - Digital Output Open-collector output; requires a pull-up resistor
Important Implementation Notes
Pull-Up Resistor Required: Because the output is an open-collector (current sinking) configuration, it cannot output a "High" voltage on its own. You must connect a resistor (typically 4.7 kΩ to 10 kΩ) between Pin 3 (OUT) and Pin 1 (VDD) to properly read the digital high/low states.
Bipolar Latching Behavior: The SS41H switches its output LOW when exposed to a magnetic South Pole, and latches into that state. It will only toggle back HIGH when it encounters an opposite magnetic North Pole.
POTENTIAL APPLICATIONS
• Industrial: Speed and RPM (revolutions per minute) sensing,
tachometer, counter pickup, flow-rate sensing, brushless dc
(direct current) motor commutation, motor and fan control,
robotics control
• Transportation: Speed and RPM (revolutions per minute)
sensing, tachometer, counter pickup, motor and fan control,
electric window lift, convertible roof position
• Medical: Motor assemblies, medication dispensing control
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