PowerPoint Name - Kenwood Academy

PowerPoint Name - Kenwood Academy

Maximizing Motor Power at Constant Voltage Principles Of Engineering 2012 Project Lead The Way, Inc. Speed Depends on Load Torque When a motor is loaded with no torque, it spins at no-load speed, w0 . w0 = no-load speed When a motor is loaded with the stall torque tstall or more, the motor will stop. tstall = stall torque

Speed vs. Torque is Linear Speed w No-load speed w0 Half speed Stall = + tstall Torque t

Speed w Optional slide for the genius: Speed vs. Torque Depends on Voltage 7 5 3 V V V m ot

m ot or or s sp ee d m 12 pe ot

0 ed or sp 90 ee d 60 Torque t Power Power = Torque x Angular Speed P=t

w Power = Torque x Speed Speed w No power. Why? w0 No power. Why? tstall Torque t

Speed w Maximum Power at Stall Torque w0 Maximum power. Why? tstall = + Torque t tstall

Why half stall torque? = + Linear equation from last slide. Multiply both = + () sides by torque, [

] = + product on left is power. Down-facing parabola. Maximum Power at 1/2 Stall Torque Power P

= + No load Maximum power tstall Torque t Stall VEX Application: Pick a Gear Ratio

Step 1. This motor is stalled. What is the stall torque? = (3 in.)(1.4 lb) = 4.2 lbin. VEX motor F = 1.4 lb tstall = d x F d = 3 in. Step 2. At what torque will the motor deliver maximum power? tmaxPower = tstall = (4.2 lbin.) = 2.1 lbin.

VEX Application: Pick a Gear Ratio Step 3. The same motor as in the last slide is being used to power a winch with a drum of radius 2 in. lifting 0.2 lb. What torque is the motor applying? d= tout = d x F n. F = 0.2 lbs 2i

= (2 in.)(0.2 lb) = 0.4 lbin. VEX Application: Pick a Gear Ratio Step 4. Instead of direct drive, what gear ratio would make the motor deliver maximum power? d= GR = n. F = 0.2 lbs

2i VEX Application: Pick a Gear Ratio Now the winch is geared so that the motor is delivering half its stall torque, for maximum power. GR GR== Human Application: Bicycle gears Can you explain why changing gears on a bike helps a person win a race that goes up and down hills? References

MIT Center for Innovation in Product Development (1999). Designing with DC Motors. Retrieved from http://lancet.mit.edu/motors/index.html Micromo (n.d.). DC Motors Tutorials. Retrieved from http:// www.micromo.com/dc-motor-tutorials.aspx Wikipedia (2009). Derailleur Bicycle Drivetrain. Retrieved from http:// en.wikipedia.org/wiki/File:Derailleur_Bicycle_Drivetrain.s vg

Recently Viewed Presentations

  • Hands-On Microsoft Windows Server 2016 2nd Edition Chapter

    Hands-On Microsoft Windows Server 2016 2nd Edition Chapter

    Chapter 1. Introduction to Windows Server 2016 ... Enables the server administrator to manage critical configuration features from inside one tool. Server Manager is used to: ... Every network device must have a unique IP address to ensure network connectivity...
  • Forming Plurals in English The usual way to

    Forming Plurals in English The usual way to

    change the ending to -ves (e.g. wives, calves), although there are exceptions (e.g. beliefs, chiefs, dwarfs, gulfs, proofs, roofs). For words that end in a vowel + y, add -s, e.g. days, boys. If a word ends in a consonant...
  • Tribal Cancer Control Education Eric Vinson Northwest Tribal

    Tribal Cancer Control Education Eric Vinson Northwest Tribal

    Develop a community awareness campaign Plan a "women's health day" to distribute information about breast health Plan an activity in connection with Breast Cancer Awareness Month (October) Record activities of awareness campaign· Record number of persons served at community health...
  • Pediatric Wilderness Medicine Concerns

    Pediatric Wilderness Medicine Concerns

    Pediatric Wilderness Medicine Concerns. Wendalyn K Little MD, MPH. Assistant Professor of Pediatrics and Emergency Medicine. Emory University. Children's Healthcare of Atlanta
  • CONCRET E POEMS Poetic Forms CONCRETE POEM   This

    CONCRET E POEMS Poetic Forms CONCRETE POEM This

    It was originally called "Pattern Poetry" or "Shape Poetry." The term "Concrete Poem" was coined in the 1950s. Present an idea graphically by using the letters and/or words to create a picture FORM If you remove the form of the...
  • www.time4writing.com

    www.time4writing.com

    Sentence Fragments. A sentence fragmentis an incomplete sentence that is missing a noun (subject) or main verb (preposition) Sentence fragmentexample: There are many things I want for my birthday. Such as a game, a toy, and money. (The second sentence...
  • Multi-Q: A Review Game - mabryonline.org

    Multi-Q: A Review Game - mabryonline.org

    Multi-Q Introduction Welcome to … M T-M U L I T Q-U L I Q!! Question & Answer Review Game Designed for Use in the Classroom Skip Rules
  • Dysfuntional Consultations

    Dysfuntional Consultations

    Dysfunctional Consultations Ramesh Mehay