HPM48-5000 Motor Overview
Axial Flux Motors
Inside the HPM48-5000
Credit: goldenmotor.com forum
Reconciling HPM48-5000 Data
Degree wheel mounted to motor shaft
Wye phase connections
Hall sensors' transitions observed while turning rotor by hand. Note glitching.
HPM48-5000 Test Curves
Credit: Golden Motor
Hall Sensors (for Motor Position Feedback)
AMP Superseal “pickoff”to observe the Hall sensors
Hall sensor signals for two phases showing a period of about 38 ms.
24 Hall Transitions per Revolution
Along with the 3 Hall sensors, a once-per-revolution index pulse was obtained by a temporary external sensor I added (pictured in the photo below). There are 24 Hall transitions (edges) per motor revolution. These edges are needed by the controller so it knows when to commutate the motor's phase windings.
Annotated Hall signals showing 24 edge transitions. Index pulse once per revolution. Running at 300 RPM (200 ms per revolution).
One Phase Voltage & Hall Signal
All 3 Phases Overlapped
The photo below shows all 3 phases overlapped. Three of the scope's input channels are connected to phase windings and the motor was spun with a handheld drill motor. Because there is no access to the neutral connection for the motor's wye, there is no common ground reference for the oscilloscope. (Although, all of the scope's input channels' grounds are connected together inside the scope.)
Golden Motor HPM48-5000's wiring location
Bad Wiring Location
I included this photo to show the location of the motor's power and sensor wires. Blue, yellow, and green are phase windings. Black is for the sensors. The ePure's Dana TM4 motor is much better in terms of wiring location.
You can also see the space Golden Motor provided for a cooling fan, but EM did not use one. The shiny tape on the shaft is a reflector for an optical tachometer I used to measure peak unloaded speed.