• What is an electric motor, and why should I care?
• Gallery of assorted motor pictures
  • AC Motors
  • AC Gearmotors
• Choosing a motor for a project
• Where can I buy one?

• Related Pages

This page from the All Electronics catalog (#103, Winter 2003) shows some AC motors.

Here's an A.C. gearmotor from my junk box.

This page from the All Electronics catalog (#103, Winter 2003) shows some AC gearmotors.

• type of operation

  Such as RC servo, stepper motor, or in this case an AC motor.

• voltage

  This indicates how much voltage (and what kind, AC or DC) must be applied to activate the motor. Watch out for current, which generally goes up as you give the motor a heavier load to move.

  Make sure that the motor matches the power you feed into it! If you feed high voltage into a low-voltage motor, the motor will burn out. Sometimes you can operate a motor on a lower voltage than is specified.

• direction

  Most AC motors go in only one direction: better buy the right one!

• speed

  Find out how fast the motor must spin for your project to work.

• torque

  Find out how strong the motor must twist for your project to work. If you can't find exactly what you want, you can use a motor that develops more torque than you need.

  Note that a AC Gearmotor trades speed for torque.

• duty cycle

  Some motors can operate 24 hours a day - "continuous duty" or "continuous operation". Other motors may develop amazing torque, but will burn out if you don't turn them off and let them cool down.

  [You may be interested to know that, in the early years of the automobile, you had to use a big crank to start the engine spinning. A lot of people wanted to use an electric motor to crank the engine, but calculations showed that such a starter motor would have to be impossibly large. Then somebody figured out that the starter motor only had to run for a few seconds, and electric starters became practical.]

• cooling requirements

  Not all of the power fed into a motor comes out as spin. Some quantity, often a lot, is wasted as heat. That heat has to escape, or the motor cooks itself.

  This is why some motors have a limited duty cycle, some have built-in fans, and others specify the air flow around the motor necessary to keep it cool.

• Electronic Goldmine
• Hosfelt Electronics
• Jameco Electronics
• Marin P. Jones & Assoc. Inc.
• All Electronics
• H&R Company, Inc. (Herbach & Rademan)
• C&H Sales Company

• electric motors
• intro to AC Electric Motors [this page]

• intro to DC Electric Motors
• RC servos
• stepper motors

Thank you for visiting. Your comments are welcome.
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