Deck 4: Timing Relays, Pressure Switches and Sensors

Question 1

Pressure switches are found throughout industry in applications where it is necessary to sense the pressure of pneumatic or hydraulic systems.

Answer 1

True

Question 2

Pressure switches are the only pressure sensing devices that an electrician is likely to encounter on the job.

Answer 2

False

Question 3

A metal bellows-type switch can sense pressures up to ____ psi.

A) 20
B) 200
C) 2,000
D) 20,000

Answer 3

2,000

Question 4

The term ____ means that the output voltage will be proportional to the supply voltage.

A) piezoresistive
B) flow-through
C) ratiometric
D) differential

Question 5

____________________ pressure is the difference in pressure between the cut-in or turn-on pressure and the cut-out or turn-off pressure.

Question 6

Describe piezoresistive sensors.

Question 7

What is the advantage of having a sensor that produces a proportional output current instead of voltage?

Question 8

The off-delay relay is often referred to as DOE, which stands for "Delay On Energize."

Question 9

Connecting eleven-pin timers into a circuit is generally even simpler than connecting the coil to power.

Question 10

____ timers operate by restricting the flow of air through an orifice to a rubber bellows or diaphragm.

A) Pneumatic
B) Clock
C) Motor-driven
D) Capacitor time limit

Question 11

Programmable controllers contain ____ electronic timers.

A) internal
B) external
C) no
D) transformed

Question 12

____________________ timers use a small AC synchronous motor to provide the time measurement for the timer.

Question 13

When a process has a definite on and off operation, or a sequence of successive operations, a(n) ____________________ timer is generally used.

Question 14

Why are pneumatic timers popular throughout industry?

Question 15

How do electronic timers provide time delays?