Radial flux AC motors offer some performance and packaging benefits but also bring some thermal and manufacturability issues. Part 1 of this series examined the axial-flux motor (AFM) in detail and compared it to the very widely used radial-flux motor (RFM). Part 2 of this FAQ continued the exploration of AFMs and RFMs. This final part […]
Motors and motor control
FAQ on axial flux motors: part 2
Radial flux AC motors offer some performance and packaging benefits but also bring some thermal and manufacturability issues. This part of the FAQ continues the exploration of AFMs and RFMs. The first part examined the axial-flux motor (AFM) in more detail and compared it to the very widely used radial-flux motor (RFM). The final part […]
FAQ on axial flux motors: part 1
Radial flux AC motors offer some performance and packaging benefits but also bring some thermal and manufacturability issues. For many electrical and even mechanical engineers, motor selection is somewhat of a mysterious process. You can understand their basic principles and operation. Still, the real-world design considerations of their flux paths, poles, materials, and tradeoffs seems […]
FAQ on servo motors: part 2
The servo motor is an older precise-positioning motor arrangement now facing some competition from the stepper motor. Part 1 of this article introduced the concept of servo motors along with servo amplifiers and servo controllers. This part continues that exploration. Q: What’s the history of servo motors? A: There were purely mechanical, closed-loop servo systems […]
FAQ on servo motors: part 1
The servo motor is an older precise-positioning motor arrangement now facing some competition from the stepper motor. When engineers need precise positioning of a motor’s shaft (rotor) angle and associated mechanical system, their first thought in many cases may be to use a stepper motor (aka “stepper”). That makes sense, as stepper motors have the […]
Miniature DC servo motor features 0.25-in stroke and high force-to-size ratio
The HVCM-016-013-003-01 Hollow Core Voice Coil Motor, features an open aperture and high force-to-size ratio. This miniature Linear DC Servo Motor from Moticont has a continuous force rating of 5.7 oz. (1.6 N) and a peak force of 17.9 oz (5.0 N) at a 10% duty cycle. Clean and quiet, this non-commutated, miniature brushless servo […]
Motor driver for BLDC applications provide full torque at zero speed
Renesas Electronics Corporation introduced a family of motor driver ICs for brushless DC (BLDC) motor applications. The devices implement Renesas’ new, patent-pending technologies that enable full torque at zero speed from motors without sensors, an industry first. The new motor driver ICs enable Renesas customers to design sensorless BLDC motor systems with higher horsepower and […]
FAQ on traction motors, part 3
Traction motors are optimized for locomotives, EVs, elevators, and other situations where high torque at start-up and low speed is needed. The final part of this article examines additional traction-motor issues. Q: What about physical size and associated issues in traction-motor applications? A: Inner-city urban light-rail vehicle (LRV) floors are typically low since the stops […]
FAQ on traction motors, part 2
Traction motors are optimized for locomotives, EVs, elevators, and other situations where high torque at start-up and low speed is needed. The previous part of this article established the context for traction motors. This part looks at traction motors in more detail. Q: What is the relative position of DC versus AC traction motors? A: […]
FAQ on traction motors, part 1
Traction motors are optimized for locomotives, EVs, elevators, and other situations where high torque at start-up and low speed is needed. Motors are an essential part of many system designs, yet their diverse variations are a mystery to many electrical engineers and a surprising number of mechanical engineers. There are several reasons for general confusion […]
