Deck 11: Timing Relays

Question 1

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

Answer 1

False

Question 2

List two advantages of clock timers.

Answer 2

Two advantages of clock timers are:
1) They have extremely high repeat accuracy.
2) Readjustment of the time setting is simple and can be done quickly.

Question 3

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

Answer 3

True

Question 4

Figure 11-6

The accompanying figure shows a bellows-operated ____________________ timer.

Question 5

Cam times are also known as ____________________ timers.

Question 6

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

Question 7

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.

Question 8

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

Question 9

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

Question 10

Briefly describe how pneumatic timers operate.

Question 11

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 12

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

Question 13

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

Question 14

What do electronic timers use as the time base?

Question 15

Clock timers are generally used to operate several switches.