2006-07

Motor/Battery Simulation Simulation of one Mabuchi RS-555PH-3550 motor over its full speed range, powered by eight AA Alkaline batteries* in series. (PDF 7kb) Simulation of two Mabuchi RS-555PH-3550 motors over their full speed range, powered by eight AA Alkaline batteries* in series. (PDF 7kb) Comparison of one Mabuchi RS-555PH-3550 motor with 3 different types of power supply. (PDF 196kb) Motor/Battery Simulation: Input parameters. (Text 2kb) Output data (1 motor). (Text 16kb) Output data (2 motors). (Text 15kb) Source code. Mesh Climber Simulation Simulation of a 4.5 kg Mesh-Climber device, with effective drive radius Re=1.0mm, with transmission efficiency of 90%, and powered by eight AA Alkaline batteries* in series: driven by one Mabuchi RS-555PH-3550 motor. (PDF 52kb) driven by two Mabuchi RS-555PH-3550 motors. (PDF 44kb) Interactive Mesh Climber Simulation. Mesh Climber Simulation: Input parameters. (Text 2kb) Output data. (Text 165kb) Source code. *Note: AA Alkaline batteries have been shown to produce a peak of 3.75 Watts of power each. This corresponds to 10 Amps of current when shorted. (Don't try this at home!) A chart of the data is available here. Measurements show that a current of about 3.5 Amps is drawn by one stalled Mabuchi RS-555PH-3550 motor, when powered by eight fresh AA Alkaline batteries. Interestingly, this stall current corresponds to a battery current, when shorted, of about 5 Amps. (The motor has internal resistance, therefore, it draws less current than a zero-resistance short.) Therefore, Ish=5.0 Amps has been used in all of the simulations shown here, producing a stall current for a single motor of about 3.5 Amps (see the green curve of battery current, at stall, in the first simulation above). Each AA Alkaline battery is rated at 2,870 [milliAmp-hrs], and therefore can deliver about 3.3 [Watt-hrs] of energy. This corresponds to 11,882 [Watt-seconds]. Eight (8) AA Alkaline batteries in series should be able to deliver about 95,056 [Watt-seconds] of energy before their combined voltage drops below 6.4 [Volts] (0.8 Volts/cell). The X-windows graphing/plotting program used to create the PDF graphs above is grace. Windows: You will need cygwin, and can get a compatible version of grace here. Mac OS X: Grace is available via the Fink software packaging system for Mac OS X. You'll also need FinkCommander, an open-source, graphical user interface for Fink which provides an intuitive front-end to the Fink command-line tools for downloading and installing Unix software. Once installed, you'll need to start X11 before running xmgrace. Double click: /Applications/Utilities/X11 | contest | teams | class | resources | people | archives | Last updated 8:33:02 PM PST, Thursday, December 21, 2006