How Does Hall Effect Position Sensing Work on PA Actuators?

How Hall Effect Sensing Works

Inside the PA-04-HS, a small magnet is attached to the rotating lead screw. As the screw turns to extend or retract the rod, the magnet passes a Hall effect sensor twice per revolution, generating two digital pulses per revolution. By counting these pulses — and knowing the lead screw pitch (mm per revolution) — the controller can calculate how far the rod has travelled.

Position Calculation - Example PA-04-HS

Lead screw pitch	~3 mm per revolution (varies by stroke — check datasheet)
Pulses per rev	2 pulses (sensor fires twice per full rotation)
mm per pulse	3 mm ÷ 2 = 1.5 mm per pulse
Pulse count	47 pulses counted since last home position

Estimated position: 47 × 1.5 mm = 70.5 mm from home. Verify with your specific model's datasheet for exact pitch values.

⚠️ Hall effect is incremental — must home after power loss Unlike a potentiometer, the Hall effect sensor counts from a reference point. If power is lost mid-stroke, the count resets. Always run a homing routine (drive to full retract and zero the count) on startup before positioning.

Hall Effect Wiring (PA-04-HS)

Wire	Colour	Connect To
Motor +	Red	H-bridge / FLTCON output +
Motor –	Black	H-bridge / FLTCON output –
Hall Vcc	Blue	5 V (Arduino) or 24 V (FLTCON)
Hall Signal	Green	Arduino digital interrupt pin (e.g. pin 2 or 3)
Hall GND	White	GND (shared with controller)

Counting Pulses on Arduino

 

 

💡 Using with FLTCON? The FLTCON series handles Hall pulse counting internally — no microcontroller code is needed. Connect the PA-04-HS directly to the FLTCON feedback headers and the controller manages synchronisation automatically. See the FLTCON user manual for pin assignments.