Smartphone apps for engineers

App details the lower operating costs of variablefrequency drives
The $aving Predictor app for the iPhone from Yaskawa America Inc., Waukegan, Ill., estimates the money saved from using variable- frequency drives (VFD) as compared to conventional methods to control threephase electric motor speeds. Users open the program and select between Fan Application and Pump Application. Then enter data such as cost per kilowatt-hour, utility rebate, motor power, and motor efficiency. Other inputs include drive cost, installation cost, operation times, and duty cycles. The app shows a payback analysis in terms of energy cost saving/year and energy saved/year. The app also shows the payback time. An e-mail button lets users easily send analysis results to colleagues.

Build your own robot “buddy”
Having a stressful day at work? Take a break and play with 123Robot for the iPhone. Open the app and the screen shows sketches of robot body parts that you can swipe to the left or right to change. For instance, swipe a goofy-looking bubble-shaped head for one that resembles R2-D2. Likewise, select among various torsos and legs (or tank treads). Pressing the Build button shows the robot in 3D color, in a Mars-like setting. A Remote control panel has sliders that let you swivel the robot’s head, torso, and legs to get particular stances.

Mechanical-engineering handbook
The Engineering Cookbook app for the Android targets mechanical engineers and includes all sorts of information about ventilation design. For example, click “Fan Types,” and the text describes the differences between axial and centrifugal fans. A list gives points to ponder before selecting a fan, including air volume required (cfm), system resistance, and air density. Push the “down” arrow at the bottom of the screen and up pops simplified versions of the most common fan laws such as cfm₁/cfm₂ = rpm₁/rpm₂. Other topics include motor and drive basics and ventilation-system design.

© 2011 Penton Media, Inc.