Electron Spin Resonance was used to study the spin-dimer compound β-Sr2Cu(BO3)2. The value of the antiferromagnetic coupling constant (J) between the copper dimers was estimated from temperature-dependence measurements to be 92 K at a frequency of 111.3 GHz and 91 K at a frequency of 66.7 GHz. Introduction From refrigerator magnets to hard drives, magnetism is a familiar phenomenon. The source ...

The commutation process causes current ripple to be generated in the drive system of brushless DC (BLDC) motor. This, in turn, leads to output torque ripple. Mechanical vibration and acoustic noise are its influences which are undesirable phenomenon in some applications. A new method is presented in this paper which reduces torque ripple and commutation period in the entire range of motor speed...

A dual mechanical port machine (DMPM) is used as an electrically variable transmission (EVT) in hybrid electric vehicle (HEV). In the conventional HEV, this machine is replaced by a planetary gearbox and two electric machines and makes this structure simpler. This paper presents field oriented control (FOC) for DMPM. For HEV application, drive efficiency and wide operating speed range are impor...

Torque measurements can significantly enhance control and monitoring loops for many mechatronic aerospace applications. A typical challenge is to justify incorporating a torque sensor in terms of cost, system complexity, reliability. Recently, sensorless estimation methods have been developed robotic joints that include harmonic drive transmissions (HDTs). The principle based on their relativel...