QSC PowerLight Series, Technical & Service Manual

Page: 79 / 100

Technical Service Manual 77
PowerLight 6.0 II, PowerLight 6.0 PFC , and PowerLight 9.0 PFC
Limiter is shown in "fast clip-tracking"mode.
To convert to a slow attack/release limiter,
open the 3 places shown shorted with lines,
and make the connection shown by the
arrow line.
VP
VN
GAIN_RETARD
Gain = 1.67
5 +
6 -
7
REREF
-POL-
PRE_LIM
+15V_
VP
11
6
3
+
8
7 5
1
4
-
2
8
4
-POL-
VP
-15V_
3 +
2 -
1
10 Vpk clips the amp
with NO LOAD.
-POL-
VP
CLIP_FEED
5 +
6 -
7
CLIP
5V=187V
3 +
2 -
1
_N_STEP
Values shown preclip a fixed
5 volts below the rails up to
15 amps of output current.
After that, preclip advances
120 mV per ampere output,
for 12v preclip at 70 amps.
Gain = 1/37.5
I_MON
_V200
MUTE
_BOP
0.84 atten.
5.95Vpk
clips amp.
3 +
2 -
1
3
+
2
-
1
5 +
6 -
7
Positive = Clip
VN
VP
With values shown, the effective
step switch time delay is 4us
flat out to 50 KHz.
CLAMP_SIG
14
+
9
10 12
16 13
-
15
-POL-
5 +
6 -
7
+POL+
3 +
2 -
1
N_ISENSE
VN
VP
P_ISENSE
DIFF_AMP_BIAS
650mV pk
excursion
Closed loop gain
=37.5 or 31.5 dB
5.0 Vp=187.5 Vp
-POL-
_BOP
_SPK_GND
_SPK
DN_DR
V
LOSS_OF_FEEDBACK
VN
UP_DR
V
PowerLight 9.0
PFC
Signal Processing