Timers and Advanced Systems

Which of the following is not a component of a time-delay relay?

• Coil

• Timing mechanism

• Alarm

• Contacts

An on-delay timer relay's contacts will not change states until

• the coil has deenergized.

• a predetermined time has elapsed.

• the coil has been energized.

• the circuit is turned off.

The __________ timer operates in a manner that is opposite to the on-delay timer.

• off-delay

• instantaneous

• pneumatic

• solid-state

In order to avoid seriously overheating the motor on a centrifugal air compressor at startup, it is recommended that

• the motor be overhauled.

• the motor be unloaded when started.

• the oil be changed every week.

• All of the above

• None of the above

One machine that uses a time-delay relay to perform a cylinder dwell is a(n)

• automatic carwash.

• centrifugal air compressor.

• plastic injection molding machine.

• washing machine.

When time-delay relays are used in time-driven sequencing, they basically take the place of

• limit switches.

• start pushbuttons.

• stop pushbuttons.

• manual overrides.

One reason why machines use multiple cylinders operating together is to

• reduce cost.

• reduce labor.

• provide extra force.

• All of the above

• None of the above

Which of the following is a method for synchronizing cylinders?

• Flow control valves

• Optical sensors

• Time-delay relay

• All of the above

• None of the above

An example of using one limit switch to control multiple cylinders is the

• crimping press.

• hydraulic press.

• printing press.

• All of the above

• None of the above