QSC PowerLight3 Series - Main Module Circuit Board Assembly; PL380 Amplifier; 4 Printed Circuit Boards; PL380 Main Circuit Board, with Major Circuit Sections Shown

58 QSC Audio Products, LLC
Top layer
See input
module drawing
Ch.1
gain pot
Ch.2
gain pot
Ch. 1 & 2
temperature
signal amps
EMI filter
board
Fan
speed
Fan
speed
Lower Speakon
(Ch. 2) output
Upper Speakon
(Ch. 1 and 2) output
Binding
post outputs
TOP switch
keep-alive supply
AC rectifiers
and reservoir
capacitors
Inrush thermistors,
relays, and fuse
HF transformer
Aux supply—
fan and audio
Class D gate
drive power
±25V supplies
HF power
rectifiers and
reservoir caps
IGBT switches and
voltage spike filter
Loss of AC
detector
Power supply
control and gate drive
transformer
Ch. 2 output
section
Ch. 2 pos.
gate drive
Ch. 2 neg.
gate drive
Ch. 1 output
filter network
Ch. 1 output
MOSFETs
Ch. 1 output
section
Ch. 1 pos.
gate drive
Ch. 1 neg.
gate drive
Power supply
section
Ch. 1 temp
sensor
Ch. 2 temp
sensor
Ch. 2 output
filter network
Ch. 2 output
MOSFETs
4.2 PL380 Amplifier
Main module circuit board assembly
Circuit board neighborhoods
PL380 main circuit board, with
major circuit sections shown