Deck 11: Timing Relays

Question 1

List two advantages of clock timers.

Answer 1

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 2

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

Answer 2

True

Question 3

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

Answer 3

False

Question 4

Briefly describe how pneumatic timers operate.

Question 5

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

Question 6

Figure 11-6
The accompanying figure shows a bellows-operated ____________________ timer.

Question 7

Clock timers are generally used to operate several switches.

Question 8

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

Question 9

What do electronic timers use as the time base?

Question 10

Cam times are also known as ____________________ timers.

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

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 13

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

Question 14

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

Question 15

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