What is the difference between a DC brushless motor and those containing brushes?
What will be an ideal response?
DC brushes are made of carbon and transfer the electricity from the power
wires going into the motor to the rotating portions of the motor. Because they are
in contact with the rotating portion of the motor, they do wear down over time and
generate sparks that could become an ignition hazard under the right conditions,
such as a flammable atmosphere. There are DC brushless motors, which negate
these problems, but they are a higher price motor.
You might also like to view...
What is the value of X in the table below?
A) 1,200
B) 1,000
C) 200
D) Cannot say; insufficient information
?Plasma cutting machines can cut mild steel ranging from _____ to _____or more in thickness.
A. ?1/4 in (6 mm) to 3 in (75 mm) B. ?1/8 in (3 mm) to 1 in (25 mm) C. ?1/64 in (0.4 mm) to 7 in (180 mm) D. ?1/16 in (1.6 mm) to 1.5 in (37 mm)
Use PSpice to determine the mesh currents in circuit in Fig. 13.139. Take ? =1 rad/s. Use k = 0.5 when solving this problem.
 figure 1.png)
A technician takes the following readings while checking the operation of an electric furnace with two heat strips: 220 V, 36 A, 70°F return air temperature, and 120°F supply air temperature. What is the airflow through the furnace?
A) = = 540 CFM B) = = 158 CFM C) (120 — 70 ) × 1.08 × 10 = 540 CFM D) = = 500 CFM