Exam 22: Dc Electronic Variable Speed Drives

Open-loop control is also called automatic control.

Mechanical vibration may loosen the mounting or alter the ____ of feedback devices.

A command signal, sometimes called the ____ or reference signal, is programmed into the DC drive and sets the desired operating speed of a DC motor.

A(n) ____ is a circuit that uses very fast electronic switches.

If the motor doesn't run, the problem must be the drive.

In which quadrant of motor operation is the motor motoring, or moving a load in the forward direction?

An electronic variable speed drive has two basic sections: the control section and the power section.

A controller's ____ determines how well it responds to changes in motor performance and is usually expressed as a percentage.

Most drive failures occur in the ____ section, where you will find power SCRs, transistors, MOSFETs, and so on.

Motor operation in quadrant ____ produces regenerative braking action when the motor turns in reverse.

The most common cause of motor failure is heat.

The control section of a DC drive uses three types of signals to evaluate motor performance: the command, feedback, and ____ signals.

Which of the following can be adjusted to detect certain levels of electrical interference or "noise," and trips the drive in the event of a voltage sag, spike, or single phasing?

Armature voltage control is the type most commonly used in DC drives.

In which quadrant of motor operation is the motor regenerating?