QSC EX-1250 Schematic

SH-004101-01 1 K

SCHEMATIC, 2-CH POWER AMPLIFIER EX 1250SCHEMATIC, 2-CH POWER AMPLIFIER EX 1250

REV E, 11-6-91, FOR PC-004101-00 REV D

DOC NO. SH-004101-01

SHEET 1, HOUSEKEEPING SUPPLY AND FAN SPEED CONTROLSHEET 1, HOUSEKEEPING SUPPLY AND FAN SPEED CONTROL

+24 V

1

+15 V

3

-15 V

4

-24 V

2

SCHEDULE OF TEST POINTS ETCJ 502-1

CH-1 CH 2

J 502-1 J 602-1 NEGATIVE LIMITING VOLTAGE
J 502-2 J 602-2 POSITIVE LIMITING VOLTAGE
J 502-3 J 602-3 SWITCHING THRESHOLD REFERENCE VOLTAGE
J 502-4 J 602-4 AMPLIFIER LOOP OPAMP OUTPUT
J 502-6 J 602-6 SWITCHED POS AMPLIFIER RAIL--HIGH VOLTAGE
J 502-8 J 602-8 SWITCHED NEG AMPLIFIER RAIL--HIGH VOLTAGE

PART NUMBERING SCHEDULE FOR PCBS USED IN EX-1250:

PCB NUMBER DESCRIPTION CH 1 PARTS CH 2 PARTS PARTS IN COMMON
PC-004001-00
PC-004002-00
PC-004101-00 AMP PCB
PC-004104-00
PC-004103-00 AC PCB

DISPLAY PCB
INPUT PCB

SPKR PCB

101-199 201-299 1-29
301-399 401-499 31-49
501-599 601-699 51-69
701-799 801-899 71-99
901-UP (SAME BOARD FOR CH 1, CH2)

+24 V UNREG

+15 V REG

-15 V REG

-24 V UNREG

+23V 0N/OFF ENABLE TRANSFORMER THERMAL SENSOR THERMAL BUS TO FAN SPEED CONTROL

U 52

7815

321

100
35 V

C 55
100 2200

35 V

D 53

1N4746, 18V

D 52

1N4746, 18V

32

1

U 51

C 53C 56

2200

35V

C 54

35V

7915

+23V 0N/OFF ENABLE TRANSFORMER THERMAL SENSOR THERMAL BUS TO FAN SPEED CONTROL

D 51

1N4004

TO SHEET 2

TO SHEET 3

BR 51

J 51

B PROD RELEASE PER ECO 1107 GLF
C REVISED PER ECO 1127 RDS
D REVISED PER ECO 1262LG
E REVISED PER ECO 1289 PHQ 11-6-91
F REVISED PER ECO 1508 SGM
G REVISED PER ECO 1602 WR
H REVISED PER ECO 2009

J REVISED PER ECO 2371 MP (EFF. 7-28-94)
K REVISED PER ECO 2506 MP (EFF. 12-09-94)

R 53

A

FAN BLK

FAN RED

3.3-1W

HEAT SINK GROUND

AUDIO AND POWER GROUNDS

XF PTC

5

XF PTC

4

18 Vac

1

18 Vac

2

CT

3

D

C

RN 51

2.7K

2.7K

-24 V

R 52

180K

C 52

47-10NP

Q 52
2N2907

Q 53

2N4410

2.7K

A

2.7K

NOTES.

1. ALL RESISTORS 1/4-WATT, 5% UNLESS NOTED.

2. ALL CAPACITORS 100V UNLESS NOTED.
TOLERANCE 20% FOR ELECTROLYTIC TYPES, 10% ON OTHER TYPES.

3. BRIDGE RECTIFIER BR 51, 1.5A, 100V.

4. R 598, 698 IS POSITIVE TEMPERATURE COEFFICIENT RESISTOR MOUNTED TO HEAT SINK.
RESISTANCE 100 OHM COLD, RISING AT 55 C. QSC P/N RE-000006-PT

5. Q 503, 504, 603, 604 ARE SWITCHING FETS. QSC P/N QD-000013-00 OR QD-000031-QD.
125 W, 50 V MINIMUM, ON-RESISTANCE 0.030 OHMS MAX.

6. ZENERS D 503, 504, 603, 604 MARKED 7.5 V TESTED FOR LOW LEAKAGE, QSC P/N QD-0007.5-ZT.

7. ZENERS D 509, 513, 609, 613, 6.2V-500mW, TESTED FOR LOW LEAKAGE, QSC P/N QD-000024-QD.

8. PARTS MARKED WITH TRIANGLE MUST BE REPLACED WITH EXACT TYPE ONLY.

9. PARTS ENCLOSED WITHIN DOTTED OUTLINE HAVE VOLTAGES GREATER THAN 42V.

R 51

47K

C 51
100-35V

C 57
.01

B

Q 51

2SC3298B

J 52-1

24 V BRUSHLESS FAN

J 52-4

5-29-91 SGM
7-12-91
10-9-91

6-10-92
10-21-92

L

5-11-94

G

7-20-94

SGM

SGM
SGM
SGM
SGM

SGM
SGM

/

RAB

LAST USED REF. DESIGN.
BR 51, BR 502, 602

C51 - 57, C526, 626
D51 - 53, D513, 613
F504, 604
J51, 52, J503, 603
K501, 601
L501, 601
Q51 - 53, Q510, 610
R51 - 53, R544, 644, R598, 698, R599, 699
RN51, RN502, 602
U51, 52, U506, 606
VR503, 603

WP-004101-10

APPLICATION

EX1250

USED ONNEXT ASSY

AUDIO PRODUCTS

PHQ 5-15-91

SH1250J1.FCD SH1250K1.FCD

SCHEMATIC EX-1250

DRAWING

SH-004101-01 K

1 3

SCHEMATIC, EX-1250, SHEET 2, AMPLIFIER CHANNEL ASCHEMATIC, EX-1250, SHEET 2, AMPLIFIER CHANNEL A

C 516 R 531

470-1W

D 512
1N400410-25V

TO -24 V

SH-004101-01 2 K

MUTE

THERMAL

SPKR SIG

14-PIN RIBBON

J 503

CLIP

GND
GND
GND

+INPUT

AUDIO INPUT STAGE

GND REF

PWR-ON

10

R 543
330K

8

C 517

220-10NP

11

C 518

470-10V

VR 502
5K
+ CURR LIM+ CURR LIM

VR 503

5K

- CURR LIM- CURR LIM- CURR LIM

C 513

470-10V

6

5

12

13

HEAVY LINE SHOWS
MAIN SIGNAL PATH

14

9

7

10K-2W

J 502-1

R 529
10K-2W

J 502-2

R 528

7.5K-2W

R 527

R 530

590

A

U 504
VTL 5C4

R 533

47K-1W

A

R 544
27K

TO +15V

R 532, 47K

TO +46 V RAIL

C 514

47-50V

C 515

47-50V

TO +15 V

TO -15 V

SPEAKER BUS

A

MUTING INPUT CAP.

T 1

TIMING CAP.

T 2

GROUND

T 3

RELAY
DRIVER

T 4

MUTE BUS

T 5

THERM ADJUST, 0.5-8.5V

T 6

THERMAL SENSE, 0-8V

T 7

THERMAL BUS, 0-8V

T 8

OP-AMP OUT - HF PROTECT

T 9

DC PROTECT SENSE

T10

THERMAL LIMITING

T11

OP-AMP OUT

T12

OPTOCELL

T13

CLIP BUS

T14

+15 V

T15

-15 V

T16

NEGATIVE BYPASS, -7.5V NORMAL, -2.5V SHORT

T17

NEGATIVE CURRENT FEEDBACK, -3V PEAK

T18

NEGATIVE TRIMMER

T19

OUTPUT VOLTAGE FEEDBACK

T20

POS CURRENT TRIMMER

T21

POSITIVE CURRENT FEEDBACK +3V PEAK

T22

POSITIVE BYPASS, +7.5V NORMAL, +2.5V SHORT

T23

NEGATIVE DRIVER, -0.6V IDLE

T24

POSITIVE DRIVER, +0.6V IDLE

T25

C 524

47-10NP

A

1.5 K

BA

+15 V

8

5

6

4

-15 V

DC

U 506-B

5532

RN 501
10K-4

ON-OFF MUTING DELAY

SHUTDOWN MUTING

RELAY
MUTE -24V
RUN +15V

THERMAL SENSING
PROCESSING BUFFER

MUTING BUS
MUTE +8V
RUN 0V

THERMAL
HIGH FREQ
DC RECTIFIER

50C +O.5V

CLIP RECTIFIER-BUFFER

LIMITING THRESHOLD +4.5V

4.5-6.5Vac CLIPPING PEAKS MUTE +4.5V

LOAD IMPEDANCE

SENSING

18pF-5%

C 522

R 540

21.5K-.5W

R 538R 536 R 537

C 521

U 506-A

R 541

590

75K

.12

C 520

.0022

R 539

47

3
2

1

C 526
27 p

1N4735

D 509
1N 4148

7

C 525

68 p

590

A

90C +8V

SHUTDOWN DETECTORS

TO MUTING

IDLE -1.2V
CLIP +3V PEAKS0-3Vac NORMAL AUDIO

NEGATIVE BIAS
CONTROLLER

BIAS ENABLE

POSITIVE BIAS
CONTROLLER

D 510

D 513

6.2 V

1N 4148

D 511

1N4735

6.2 V

U 503

IC-000010-00

U 501
IC-000008-00

SCHMIDTT COMPARATOR

LOSS-OF-SAT

SHUTDOWN

REF VOLTT2LOW RAIL

T1

D 504

7.5V

+46 V RAIL

J 502-3 J 502-6

VR 501
100

BIAS

BIAS

R 599

50 OHM

25 C

C 504
.01

BIAS

NETWORK

D 505

1N4004

C 512

.0033

D 506

1N4004

U 505-B

D 503

7.5V

C 519

+15 V
8

5

6

4

-15 V

R 534 C 523

2.7K

A

680p

T1

REF VOLT

SCHMIDTT
COMPARATOR

U 502
IC-000009-00

R 598
PTC-60C

J 502-4

+23V 0N/OFF ENABLE TRANSFORMER THERMAL SENSOR THERMAL BUS TO FAN SPEED CONTROL

TO SHEET 1

THERMALLY
CONNECTED
TO Q 508

7

SWITCHING THRESHOLD

.0022

T2

U 505-A

5532

R 535
15K

REFERENCE

-46 V RAIL

LOW RAIL

1

C

D

RN 502

1K-4

3

2

LOSS-OF-SAT

SHUTDOWN

SHUTDOWN

T3

SPEAKER BUS

B

A

T3

SHUTDOWN

GATE DRIVER

SLEW NEG SUPPT6BOOTSTRAP CAP

T4

R 508

332

R 503 R 506

1.5K

750K

R 501 R 505

1.5K

750K

R 507

332

T4

SLEW

GATE DRIVER

T5

J 502-8

R 519
22-1W

R 518
22-1W

HIGH RAIL

GATE

SOURCE REF

C 502 47-50V

R 513 22K-1W

R 520 R 521 R 522

Q 508 Q 509 Q 510

Q 502

2SC3298B

R 504

4.7-1W

R 502

4.7-1W

Q 501
2SA1306B

AUDIO OUTPUT STAGE

Q 505 Q 506 Q 507

R 516 R 515 R 517

GATE PWR

GATE

SOURCE REF

SOURCE REF

+92 V RAIL

T9

T8

T7

+46 +92 V SWITCHED BUS

2SA1302

3 PL

2SC3281

3 PL

-46 -92 V SWITCHED BUS

T5

T6

T7

-92 V RAIL

D 508

1N5402

D 507
IN5402

D

GS

R 512 C 503

2.7-2W .10

HEATSINK
GROUND

C 507

.10

R 509 C 501

2.7-2W

D

GS

R 511 Q 504

22 FP

.22-3W

3 PL

.22-3W

3 PL

R 514
3K-2W

R 510

22 FP

C 505
470-10V

D 502

MUR 810

D 501

MUR 810

Q 503

R 524

3.9-2W

.10

C 509

15000-50V

C 511

15000-50V

L 501

R 525

5.6-2W

C 510

15000-50V

C 508
15000-50V

2uH

R 523

5.6-2W

C 506
.10

R 526
3K-2W

R 542
47K-1W

TO -15V

TO -92 V RAIL

TO -46 V RAIL

TO -24 V

TO RECT BR 501

TO RECT BR 502

SH1250K2.FCD

BR 502

BR 501

F 502

10A-250V

F 504

10A-250V

F 501

10A-250V

F 503

10A-250V

J 501

6-PIN MATE-LOK

3

4

6

1

TRANSFORMER
CENTER TAP

2

5

K 501

NO

NC

J 52-5

SPEAKER
OUTPUT

SPEAKER
COMMON

J 52-6

SH-004101-01 K

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