Chapter 16: Timing and Counting Functions

stand-alone

Dashpot, synchronous, and solid-state timers are _____ timers.

Solid-state

______ timers are the most common stand-alone timer used in control applications today.

dashpot

A _____ timer is a timer that provides time delay by controlling how rapidly air or liquid is allowed to pass into or out of a container through an orifice (opening) that is either fixed or variable in diameter.

epoxy resin

Solid-state timers are less susceptible to outside environmental conditions because they, like relay coils, are often encapsulated in ____ for protection.

input

The _____ section of a PLR is where the circuit's digital (ON/OFF, OPEN/CLOSED, etc.) switches are connected.

Dashpot

_____ timers are the oldest type of industrial timers.

Solid-state

_____ timers are normally discarded when they fail since they cost less than other timers.

on-delay

A(n) ____ timer can be designed to open or close a circuit after a preset time delay.

off-delay

A(n) ____ timer may also be used for plugging a motor to a stop during emergency stops.

one-shot

A(n) _____ timer is a device in which the contacts change position immediately and remain changed for the set period of time after the timer has received power.

asymmetrical

A(n) ____ recycle timer is a timer that has independent adjustments for the on and off time periods.

On-delay

____ timers are the most common type of timer in use.

operational

In a(n) _____ diagram, the top line shows the position of the control switch and the bottom line shows the condition of the load.

recycle

A(n) ______ timer is a device in which the contacts cycle open and closed repeatedly once the timer has received power.

Wiring

_____ diagrams are required on multiple-contact timers because several different connection points must be located and wired to the timer for it to perform properly.

O

A(n) "____" indicated when the load is de-energized.

Supply voltage

A _______________ -controlled timer is a timer that requires the control switch to be connected so that it controls power to the timer coil.

contact

The advantage of the _____ control method is that the control switch can be wired using low-voltage wire (AWG 16, 18, or 20).

sensor

A(n) _____-controlled timer is a timer controlled by an external sensor in which the timer supplies the power required to operate the sensor.

Memory

_____ could be added to a circuit if the circuit requires a momentary input, such as a pushbutton, to initiate timing.

contact

The most common problem of contact-based timing circuits is _____ failure.

555

A ___ timer is an integrated circuit (IC) that can function as either a timer or an oscillator.

capacitor

A variable resistor and a(n) _____ are used to determine the amount of time delay in a 555 timer.

12.34

A preset value of 1234 with a time base setiing of 0.01 sec is equal to _______________ sec.

nonretentive

A(n) _____ timer is a timer that does not maintain its current accumulated time value when its control input signal is interrupted or power to the timer is removed.

transistor

Modern industrial control circuits are often connected to DC electronic circuits that include a(n) ______ as their output.

flip-flop

A ______ is the electronic equivalent of a toggle switch.

real-time

A _____ clock allows for outputs to be turned on and off at preset times of the day and days of the week.

totalizer

A ___ is a counting device that keeps track of the total number of units or events and displays the total counted value.

up

A(n) ______ counter is a device used to count inputs and provide an output (contacts) after the preset count value is reached.

up/down

A(n) _______________ counter is a device used to count input from two different inputs, one input that adds a count and another input that subtracts a count.

totalizer

A(n) ______ can be used when only the total number of units or events is required to be known.