Answers and Explanations

  1. The student must show their face in the video for credit.
  2. The student must be wearing safety glasses covering their eyes to get credit.
  3. The student must submit a legible schematic. See the examples below for this lab schematic. Only one schematic is required for submission, but either or both options are acceptable. The student can either show the industrial style or the electronic style, and they can show either with or without the latch.
    1.  AMAR-1200-Lab 11-4 - DC Series with Relay-1.PNG  
    2.   AMAR-1200-Lab 11-4 - DC Series with Relay With Latch.PNG  
  4. The student must have their name, date, and lab number on the schematic.
  5. The wire colors must be on the schematic.
  6. All components must be labeled. This includes circuit breakers, push buttons, switches, motors, fans, solenoids, resistors, etc.
  7. The drawing must be wired to their schematic.
  8. The "Unlatch" circuit must work.
  9. The "Latch" circuit must work.
  10. Student should explain why a latch circuit would be used. The most simple reason is to hold a motor on running without having to stand by the motor all day holding the button. When a stop button is pressed, the motor will stop and wait for the start button to be pressed to start backup.
  11. The latch circuit works, because as the student presses the button, it turns on the relay. When the relay energizes, the contacts 8 and 6 close. This creates a jumper around the push button. Thus, the push button can go off and power will be jumpered around it. When the switch is turned off, the power through 8 and 6 turns off and the relay deenergizes.  Then, when the switch is turned on, the circuit must have the push button pressed again to re-engage the relay.
  12. The student clearly shows lockout/tagout in their video.
  13. The student clearly shows that they have verified with a multimeter that the voltage is at or near 0V.

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