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Solenoids, DC Motors

Solenoids, DC Motors. And the fine art of Snubbing. Solenoids. Most Common Solenoid Types. Push. Open-Frame. Rotary. Pull. Solenoid Characteristics. Design Affects Stroke vs. Force Characteristic. Typical Solenoid Specifications. DC Motors provide Rotary Motion. Where do you find them?.

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Solenoids, DC Motors

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  1. Solenoids, DC Motors And the fine art of Snubbing

  2. Solenoids

  3. Most Common Solenoid Types Push Open-Frame Rotary Pull

  4. Solenoid Characteristics

  5. Design Affects Stroke vs. Force Characteristic

  6. Typical Solenoid Specifications

  7. DC Motors provide Rotary Motion Where do you find them?

  8. The Permanent Magnet DC Motor

  9. Commutation

  10. Electrical Model of a DC Motor

  11. Deriving some useful relationships

  12. More Room for Derivations

  13. Torque vs. Speed Power vs. Torque

  14. How Does P change with V at Constant T?

  15. Where is PMAX and What is its Value?

  16. Torque vs. Everything

  17. DC Motor Specifications

  18. Operating Ranges

  19. Defining ‘Short Term Operation’

  20. CMPE-118 DC Motor Lecture Problem • You have been assigned to follow up on the design of a former employee who had not taken CMPE-118. Your supervisor suspects that they didn't know what they were doing. The only documentation that you can find shows that the motor chosen has Kt = 9.33 in.-oz./A and produces 2.8 in.-oz. at stall when driven at 12V. The design requires that the motor deliver 0.4 in.-oz. at 1500 rpm. The motor was supposed to be driven from a 12V supply and switched by a ULN2003. Your boss has asked you: • a) How can I find out how much current the motor will draw at stall ? • b) Can the ULN2003 safely switch the required current? • c) How can I find the NL Speed ? • d) How can I find the coil resistance ? • e) How can I find the torque at a given speed ? • f) Will the design meet the requirements for torque & speed? If not, what changes could you suggest? • g) To estimate the current required when running at the design point. • You may assume that there are no internal losses within the motor. • KT = 1.3524KE [oz-in/A ; V/krpm]

  21. Motor Design Solution Kt = 9.33 in.-oz./A Tstall = 2.8 in.-oz. Vstall = 12V. Treq = 0.4 in.-oz. wreq =1500 rpm. KT = 1.3524KE [oz-in/A ; V/krpm]

  22. Directional Control With a Single Power Supply The H-Bridge

  23. Pulse Width Modulation

  24. DC Motor Drive Simulation

  25. Drive Waveform Volts

  26. Transistor Current Current (A)

  27. Inductor Current

  28. Collector Voltage Volts

  29. Diode Snubber

  30. Collector Voltage w/ Diode Snubber Volts

  31. Inductor Current w/ Diode Snubber Current(A)

  32. How would we add diodes to protect the H-Bridge?

  33. How would we add Zener diodes to protect the H-Bridge?

  34. The Brushless DC Motor

  35. Commutating a Brushless DC Motor

  36. Hall Sensor Based Commutation

  37. Brushed vs. Brushless DC Motors

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