CMPE 118 MECHATRONICS Solenoids, DC Motors And the fine art of Snubbing

CMPE 118 MECHATRONICS Solenoids

CMPE 118 MECHATRONICS Most Common Solenoid Types Pull PushOpen-Frame Rotary

CMPE 118 MECHATRONICS Solenoid Characteristics

CMPE 118 MECHATRONICS Design Affects Stroke vs. Force Characteristic

CMPE 118 MECHATRONICS Typical Solenoid Specifications

CMPE 118 MECHATRONICS DC Motors provide Rotary Motion Where do you find them?

CMPE 118 MECHATRONICS

The Permanent Magnet DC Motor

CMPE 118 MECHATRONICS Commutation

CMPE 118 MECHATRONICS Electrical Model of a DC Motor

CMPE 118 MECHATRONICS Deriving some useful relationships

CMPE 118 MECHATRONICS More Room for Derivations

CMPE 118 MECHATRONICS Torque vs. SpeedPower vs. Torque

CMPE 118 MECHATRONICS How Does P change with V at Constant T?

CMPE 118 MECHATRONICS Where is P MAX and What is its Value?

CMPE 118 MECHATRONICS Torque vs. Everything

CMPE 118 MECHATRONICS DC Motor Specifications

CMPE 118 MECHATRONICS Operating Ranges

CMPE 118 MECHATRONICS Defining ‘Short Term Operation’

CMPE 118 MECHATRONICS 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 K t = 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. K T = K E [oz-in/A ; V/krpm]

CMPE 118 MECHATRONICS Motor Design Solution K t = 9.33 in.-oz./A T stall = 2.8 in.-oz. V stall = 12V. T req = 0.4 in.-oz.  req =1500 rpm. K T = K E [oz-in/A ; V/krpm]

CMPE 118 MECHATRONICS Directional Control With a Single Power Supply The H-Bridge

CMPE 118 MECHATRONICS Pulse Width Modulation

CMPE 118 MECHATRONICS DC Motor Drive Simulation

CMPE 118 MECHATRONICS Drive Waveform Volts

CMPE 118 MECHATRONICS Transistor Current Current (A)

CMPE 118 MECHATRONICS Inductor Current

CMPE 118 MECHATRONICS Collector Voltage Volts

CMPE 118 MECHATRONICS Diode Snubber

CMPE 118 MECHATRONICS Collector Voltage w/ Diode Snubber Volts

CMPE 118 MECHATRONICS Inductor Current w/ Diode Snubber Current(A)

CMPE 118 MECHATRONICS How would we add diodes to protect the H-Bridge?

CMPE 118 MECHATRONICS

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

CMPE 118 MECHATRONICS The Brushless DC Motor

CMPE 118 MECHATRONICS Commutating a Brushless DC Motor

CMPE 118 MECHATRONICS Hall Sensor Based Commutation

CMPE 118 MECHATRONICS Brushed vs. Brushless DC Motors

CMPE 118 MECHATRONICS