Vol. 5 No. 1 (2023)

Open Access

Article

Article ID: 766

Design and Implementation of Torque Control and Estimation for an Electric Hand-Tool

by Tian-Hua Liu, Cheng-Wei Peng

Current Electronics and Telecommunications, Vol.5, No.1, 2023; 353 Views, 9 PDF Downloads

This paper proposes the design and implementation of torque control and torque estimation for an electric hand-tool. This hand-tool does not require any torque transducer or any Hall-effect sensor. Only some low-cost resistances are used to measure the stator currents of a brushless DC motor, which is used to drive the hand-tool. Novel 3-phase current commands are proposed here to obtain greater torque than traditional 3-phase, square-wave current commands. The output torque of the hand-tool can be estimated and displayed by an LED display. A PI controller is used to achieve the current-loop control. A digital signal processor, TMS-320-F2808 that was manufactured by Texas Instruments, is used to execute the control and estimation algorithms. Experimental results show the correctness and feasibility of the proposed methods.

Open Access

Article

Article ID: 639

Development of Satellite Communication

by Linjie Yao, Guangxi Xu, Haiqing Yang

Current Electronics and Telecommunications, Vol.5, No.1, 2023; 213 Views, 35 PDF Downloads

Satellite communication refers to the use of artificial earth satellites as a relay station to forward radio waves, between two or more earth stations in the communication. Satellite communications since 1945 development so far, greatly accelerating the process of social information. The research and use of our satellites began in the early 1970s. Satellite communication applications include applications in data transmission services, applications in mobile communication systems, applications in video broadcast services, and applications in interactive services such as telephony. With the advancement of satellite communication technology and the improvement of satellite communication capability, the application of satellite communication is becoming more and more extensive, and the service level is getting higher and higher. In today's rapid development of terrestrial communications, satellite communications in the development of the market despite the great difficulties and risks, and even suffered major setbacks, but because of its irreplaceable characteristics of the decision it is still to develop and application. Therefore, from the overall and long term, the future development prospects of satellite communications is still bright and beautiful. China's satellite communications development goals: good management, make good use of existing satellite communications systems, and actively develop new business, new markets, new systems and adhere to independent construction.