Version 1.0, August 31, 2001, Copyright, Hugh Jack 1993-2001

13.13 PRACTICE PROBLEMS

 

1. Suggest a couple of methods for collecting data on the factory floor

(ans. data bucket, smart machines, PLCs with analog inputs and network connections)

 

2. If a thermocouple generates a voltage of 30mV at 800F and 40mV at 100F, what voltage will be generated at 1200F?

 

1. A certain potentiometer is to be used as the feedback device to indicate position of the output link of a rotational robot joint. The excitation voltage of the potentiometer equals 5.0 V, and the total wiper travel of the potentiometer is 300 degrees. The wiper arm is directly connected to the rotational joint so that a given rotation of the joint corresponds to an equal rotation of the wiper arm.

  1. a) Determine the voltage constant of the potentiometer Kp,
  2. b) The robot joint is actuated to a certain angle, causing the wiper position to be 38 degrees. Determine the resulting output voltage of the potentiometer.
  3. c) In another actuation of the joint, the resulting output voltage of the potentiometer is 3.75V. Determine the corresponding angular position of the output link.

 

1. How is the efficiency of a motor defined?

 

2. What is the relationship between Real Power, Reactive Power and Apparent Power? (A sketch is acceptable)

 

3. What is the definition of the power factor of a motor?

 

4. Name two ways to improve motor efficiency.

 

5. Name two types of inputs that would be analog input values (versus a digital value).

 

6. Describe the following as either Transient or Steady State problems with respect to Power Quality:

Spike _______________________

Electrical Noise _________________________

Tingle Voltage _______________________