DC MOTORS

EET 390 LAB

LEE YANG

&

TIM LAWSON

TIMELINE OF THE DC MOTOR• Invention of the battery (Allessandro Volta, 1800)

• Magnetic field from electric current (Hans Christian Oersted, 1820)

• 1820 André-Marie Ampère (French) invents the cylindric coil (solenoid)

• 1821 Michael Faraday (British) creates two experiments for the demonstration of electromagnetic rotation.

• Electromagnet (William Sturgeon, 1825) the foundation for building electric motors was laid.

• 1831 M. Faraday discovers and investigates electromagnetic induction

• May 1834 Moritz Hermann Jacobi finish constructing the electric motor which produce 15 Watts of mechanical power

• The DC motor was created from development of power generators (dynamometers). The foundations were laid by William Ritchie and Hippolyte Pixii in 1832 with the invention of the commutator and, most importantly, by Werner Siemens in 1856 with the Double-T-anchor and by his chief engineer, Friedrich Hefner-Alteneck, in 1872 with the drum armature.

• 1885 to 1889 the invention of the three-phase electric power system

Hippolyte Pixii

William Ritchie

Faraday demonstration of electromagnetic rotation.

REAL WORLD APPLICATIONS

DC MOTOR EXPLANATION

http://www.youtube.com/watch?v=QgMNay114-4

• DC Motor - YouTube

COMPONENTS OF DC MOTORS

HOW TO CONTROL MOTOR SPEED WITH A PWM CIRCUIT

Pulse-width modulation is an effective method for adjusting the amount of power delivered to an electrical load. A simple circuit containing an inverter chip, diodes, trim pot, and capacitor creates the variable duty-cycle PWM. A resistor and transistor switch heavier loads than the 74AC14 chip can drive by itself.

RESOURCES

• http://www.robotroom.com/PWM5.html

• http://www.youtube.com/watch?v=QgMNay114-4

• http://www.eti.kit.edu/english/1376.php