Veeder Root Electronic Timers General Product Information
INTRODUCTION
Electronic Timers
Electronic timers exist because many processes are based
upon timed events. They are available in many forms each with
a major characteristic best suited for a particular application.
Electronic timers can be found in a broad spectrum of industrial
and commercial applications where the highest accuracy and
resolution is required.
Eagle Signal brand industrial timers have a 70 year history of
providing accuracy and reliability in harsh industrial environments.
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Plastic Working Equipment
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Food Processing Machinery
Material Handling Controls
The reset timer can be considered a single cycle timer. Most
reset timers are used to turn a load ON
turn a load ON
be in one of three states: Reset, Timing, and Timed-Out. When
reset, the timer does not perform any timing function. The
timing period starts when an external signal is received. The
timed-out state is the period between the end of timing and
when the timer returns to the reset state.
A
repeat cycle timer
cycle of turning a load on and off in a repeating pattern as long
as power is applied to the unit. Repeat cycle timers are
produced in many varieties and types. All Eagle Signal brand
electronic repeat cycle timers allow separate adjustment of the
ON and OFF times. Some repeat cycle timer models have
batch counters and allow dwell times between ON and OFF
periods.
ADVANTAGES OF ELECTRONIC TIMERS
Electronic timers and time indicators bring the advantage of
modern digital displays, precise digital settability, high accuracy
and fast reset times. Although electromechanical controls
provided accurate and reliable time control, the electronic timer
is specified for its modern appearance, high precision and
advanced features. Digital electronic timers use LCD or LED
displays and offer high accuracy and long time ranges.
They typically have fast reset times and are available in
compact DIN standard enclosures.
Liquid Crystal Displays (LCD) are best suited for installation in
areas where there is reasonably good lighting.
Light Emitting Diode (LED) displays, since they produce their
own light can be viewed in very dimly lit areas -even in the
dark.
after a timed interval
just as the name applies, repeats the
for a timed interval
. A reset timer can either
or to
Xjr Count/Rate 4
Packaging Machines
TYPICAL RESET AND RECYCLE TIMER APPLICATIONS
TYPES OF ELECTRONIC TIMERS
time indicator
A
an elapsed time but performs no output function. Various
models are available with LED or LCD displays. A time
indicator will time in increments of fractions of a second up to a
total time of several minutes, or in increments of one hour up to
a total time of several years.
A
reset timer
by an external command, then measures a specific time
interval, after which it becomes inactive once again. It times
through a preset time period, produces a control output, then is
automatically or manually reset, awaiting another cycle to
begin.
DANAHER INDUSTRIAL CONTROLS
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is simply a device which records and displays
is a control device. It is inactive until it is started
Pump Controls
B506
CX200
TYPICAL ELECTRONIC RESET AND RECYCLE TIMERS
B90D
SX210
LCD Display
LED Display
Cycle Rate:
Action on Power Failure
How often will the timer switch the load.
- After a failure, what should the
timer do upon restoration of power?
Operator Restraints
Special Requirements
- Lighting, gloves, low skill level
- NEMA-4 Washdown, High temperature and humidity, High vibration, Corrosive atmosphere,
Electrical interference and brownouts
Agency Approval
- U.L., CSA, FM
TYPES OF ELECTRONIC DISPLAYS
SPECIFYING AN ELECTRONIC TIMER
The following criteria should be considered when selecting an
electronic timer for your application:
Control Function
Time Range
Mounting
- Jack-in case, Panel mount, Surface mount,
- Reset function, repeat cycle function.
- What time range will the timer use?
DIN rail mount, Timer lock
Size
- What are the size limitations if any for the timer?
Service Voltage and Frequency
- 12 VDC, 24 VDC, 24 VAC,
120 VAC, 240 VAC; 50 Hz, 60 Hz., Other
Setting Accuracy
- What is the minimum setting accuracy
required for the time setting?
Repeat Accuracy
- What is the minimum repeat accuracy
required for the timing cycle?
Front Panel
- What type of interaction does the operator need
to have with the front panel controls of the unit?
Load
- What device will be controlled by the timer and what
are the electrical specifications for this load?
ELEMENTS OF ELECTRONIC TIMERS
All electronic timers will have three basic elements: (1) Control
Input, (2) Timing components (3) Output Elements
Timing
Components
Control
Output
Control Input
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Timer Electronic Timer
Control Inputs Timing Components Control Outputs
AC voltage Microprocessor Instantaneous
Relay
DC voltage Integrated Circuit Delay Relay
Contact Triac
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A103
7999 MITE
TYPICAL ELECTRONIC TIME INDICATORS
DANAHER INDUSTRIAL CONTROLS
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