Watlow Series 982 - Manual (Page 117)

WATLOW Series 982 User’s Manual 9.3 Software Features, Chapter 9
Software
TL
TL
W WA
PROCESS
L1 L2 L3 L4
DEV
% OUT
DISPLAY
SERIES 982
MODE
HOLD
RUN
input 1 output 1
QPAC
with
QCD
input
limit
S e mic onduc t or O v e n
temperature
sensor
limit
sensor
heated platen
50% output
1 ON, 1 OFF
10% output
1 ON, 9 OFF
100% output
10 ON, 0 OFF
66% output
2 ON, 1 OFF
Sample Application
A Series 982 controls a heated platen in a semiconductor oven. Previously
it used a power control requiring a 4-20mA signal to implement burst-fire
control. We have replaced the power control with a Watlow Loyola QPAC
with a QCD card that accepts a signal directly from an open-collector out-
put of the Series 982. This gives smooth control at a lower overall system
cost.
Figure 9.3b -
Semiconductor
oven with burst
fire.
Figure 9.3a - Sine
waves of burst
fire settings.