Global ETD Search

1	Propulsion Unit of a 3DOF Helicopter Ling, Gustav, Persson, Jesper January 2015 (has links) This Bachelor thesis is a part of a bachelor project which includes building, programming and controlling a 3DOF tandem helicopter. This particular report deals with the propulsion units, i.e. the motors and propellers of the helicopter. It covers the process of how to determine the most suitable propulsion units for the rig that eventually will enable it to run. To achieve this, different data have been processed. Torque and thrust are two important parameters that have been studied. The data have been acquired by different tests, e.g. thrust measurements from a thrust rig. Also more complex analysis such as Blade Element Theory and Actuator Disk Theory have been carried out in order to determine the behaviour of the propulsion units. Study data sheets and databases was also a part of the work. The result of this work was two equal propulsion units which were mounted in the helicopter. They proved to work satisfactory and provided wanted dynamics to the system. / Design & Implementation of a 3DOF Helicopter propulsion unit helicopter rig dynamics thrust rig mechatronics 3DOF tandem helicopter DC motor brushless DC motor brushed DC motor APC Maxon propeller mount tandem helicopter
2	Investigation of electromagnetic compatibility (EMC) of low-voltage (<60V) DC electric motors in construction machinery application Luong, David, Salloum, Ibrahim January 2019 (has links) The brushed DC motor is a source of electromagnetic emission that may cause interference. The main issues with brushed DC motor are arcing, which occurs between the brushes and commutator, and inrush current. It is possible to decrease the electromagnetic emissions by addressing the source (brushed dc motor) and the installation. The source may be addressed by using filters in the form of X2Y-capacitors on the terminals or ferrites on the cables. The installation does not produce any emission, but it is possible to lower its contribution. This is done by altering the installation like changing the placement of cables and provide good coupling. An effective way of decreasing inrush currents is by using negative-thermal-coefficient (NTC) thermistors. Another measure to improve the EMC properties of the brushed DC motor is to design the motor so that it can trap EM emissions. Some of these parameters are motor house material, end-cap material, vent holes or slots on motor housing, placement of power terminals, crimping tabs and motor enclosure. EMC brushed dc motor arcing inrush currents X2Y capacitor NTC thermistor common mode ferrites differential mode ferrites grounding cable placement motor design parameters Annan elektroteknik och elektronik

1

Page generated in 0.0659 seconds