Answer Happy

Figure 1 shows an elevator system in which a cable is woundaround a grooved cylindrical
sheave (drum) that has the elevator cage on one end and acounterweight on the other. The
sheave is of the radius r = 0.2 m and driven by a DC machinethrough a 1:10 step-down
gearbox. The empty cage has a mass of 125 kg and thecounterweight has a mass of 425 kg.
The DC machine has the parameters Ra = 0. 6 2 and k$ = 1.5 Nm/A.And controlled by
a PWM, 4-quadrant Chopper (H-bridge) in which, in turn, suppliedby a 150-V DC source.
The set-up is such that a counter-clockwise rotation of themachine corresponds to an upward
movement of the cage.
1)Calculate the average motor current la, average terminalvoltage va,
and the duty cycle required for an upward movement of the cagewith 9 (nine) 75-kg
passengers and at a constant speed of V = 0.8 m/s (Note: F = mg,where g ~
10 N/kg and m is the net mass). Show your work and list finalresults in Table 1
Repeat Part (1) if the cage moves up with 3 (three) 75-kgpassengers and at a
constant speed of V = 0.9 m/s. Show your work and list finalresults in Table 2.
Repeat Part (1) if the cage moves down with 3 (three) 75-kgpassengers and at a
constant speed of V = 0.9m/s. Show your work and list finalresults in table 3.
Motor 10:1 Gear Sheave Counterweight V Cage Figure-1: elevator system of Q1.
Table 1 ia (A) Va (V) d
Table 2 ia (A) Va (V) d
Table 3 ia (A) Va (V) d