CAPACITOR POWER BOLD-UP OPTION
(
A
c
Supply PRIDE"Onlyl
The PRIDE is designed to operate over a wide range of power supply voltages and wave shapes. The
Capacitor Power Hold-Up Option is available if an
Ac
Supply PRIDE is required to ride through (no
tripping) a loss of input power for up to
3
sec.
The circuit board, that mounts in the bottom
compartment of the
PRIDE,
provides energy storage so that the
PRIDE
Unit
can
continue to operate for up
to
3
sec even if the input f(>We[ source fails.
In cases where delayed tripping is required, the PRIDE
will time out
and
delay tripping for up to
3
sec maximum.
� CAUTION:
If the
M-0297/M-0397
Field Adjustment Unit is mounted in the PRIDE,
the power switch on the
M-0297
PRIDE
Control Unit sho u l d be kept in the OFF
p o s ition unless the Field Adjustment unit is in use.
W ith the
M-0297
power
swi t c h in t h e
ON
p o s i t i o n , t h e u n i t wi l l not o p e r a t e f o r t h r e e s e c o n d s a f t e r
a power interruption.
WATCHDOG TIMER
'lbe
Watchdog Timer performs the flD'lction of overlooking the program flow of the microprocessor.
The
watchdog will reset the microprocessor back to an orderly start-up sequence if the program flow is
upset or if the software does not perform an operation within the allotted time period.
The
microprocessor will periodically update or "refresh" the watchdog to keep it out of a reset conditi�
POWER ON CLEAR
The Power On Clear block is an RC circuit which insures that a proper Power Up sequence has been
accomplished when power is first applied to
the
unit.
SQUARING CIRCUIT
'!be Squaring Circuit converts the sinusoidal inputs to .equare waveS. The microprocessor can use these
inputs to determine the period (and thus frequency) of the ac input.
OVERVOLTAGE DETECTOR
Based on properly chosen component values, the Overvoltage Detector will trip, signaling the
microprocessor of an overvol tage condition.
UNDERVOLTAGE DETECTOR
The Undervoltage Detector works in the same manner as the overvoltage detector. signaling the
microprocessor of an undervoltage conditia4
AC
t o
DC
rus block converts the sine wave inputs to a dc value proportional to the amplitude of the sinusoidal
input.
LED
and
RELAY DRIVE
Because of the microprocessor1s low current-sourcing cat;:ability, added drive is needed for {X>Wering the
LED
indicators and relay�
-14-
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