Deck 11: Timing Relays

Question 1

The on-delay relay is often referred to as DODO.

Answer 1

False

Question 2

Clock timers are generally used to operate several switches.

Answer 2

False

Question 3

Timer relays are similar to other control relays in that they use a(n) ____________________ to control the operation of some number of contacts.

Answer 3

coil

Question 4

List two advantages of clock timers.

Question 5

The abbreviations TO and ____________________ are used with some control schematics to indicate a time-operated contact.

Question 6

Cam times are also known as ____________________ timers.

Question 7

Clock timers use a small AC ____________________ motor similar to the motor found in a wall clock to provide the time measurement for the timer.

Question 8

What do electronic timers use as the time base?

Question 9

Pneumatic timers are affected by variations in ambient temperature or atmospheric pressure.

Question 10

In cam timers, how is the operation of the switches controlled?

Question 11

Briefly describe how pneumatic timers operate.

Question 12

Figure 11-6


The accompanying figure shows a bellows-operated ____________________ timer.

Question 13

What are the two general classifications in which time delay relays can be divided?

Question 14

Pneumatic timers are adjustable over a wide range of time periods.

Question 15

Instantaneous contacts change their positions immediately when the coil is energized and change back to their normal positions immediately when the coil is de-energized.