Service manual

ManualsBrandsBose Manualsaudio cardsOC-1 AWCS-II

1994 Bose Corporation Service Manual

OC-1 AWCS-II Option Card

Summary of content (22 pages)

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TABLE OF CONTENTS 1. SPECIFICATIONS.................................................................................................... 2 2. THEORY OF OPERATION....................................................................................... 3 3. EQ CURVES............................................................................................................. 5 4. BLOCK DIAGRAM.................................................................................................... 8 5.
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OC-1 SPECIFICATIONS Dimensions: .63" Hx1.29"Wx8.98"D(1.6x3.3x22.8 cm) Weight: .09 lbs. (.042 kg.) Input/Output: 2 audio inputs,Channel 1 and 2 high frequency outputs, bass channnel output Input Impedance: (feedback input) 482 kΩ (nominal) Output Level: 5.0 Vrms into 10 kΩ Crossover Frequency: 125 Hz,Roll-off slope: 24 dB/oct. Output Noise: ≤ 40µV (A-weighted) Channel Separation: 50 dB (min.
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THEORY OF OPERATION Overview The OC-1 is a small plug-in module for use with Bose 502™, 402™, and 802® II controllers. The OC-1 allows the use of the Cannon™ bass loudspeaker with these controllers and their loudspeakers. Refer to the block diagram, equalization curves and OC-1 schematic for further information. The OC-1 provides three major functions: A. Low frequency equalization. B. Crossover filtering of the high frequency signals. C. Protection of the Cannon against excessive power. 1.
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U4, sections 1 and 2 form a full-wave peak detector. When the input to these stages exceeds +/-2V peak, the outputs go high and a control voltage is created in the averaging circuit (C27, C28, etc.). The averaging circuit captures peaks with a short attack time and holds them with a longer release time. U2, section 2 inverts and scales the averaged control voltage and applies it to the VCA control input. U7 is a current-in/current-out VCA which is controlled by the voltage on pin 2. 5.
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Output is measured from U3 pin 7 or U6 pin 1. Controls are set at:: Mode 4 (Option), Output Mode: Normal, Low Frequency Level: 0 dB, and Input Level: +4 dB. Figure 1. High Frequency EQ Output is measured from U5 pin 14. Controls are set as in Figure 1. Figure 2.
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Output is measured from U5 pin 1. Controls are set as in Figure 1. Figure 3. EQA + EQB + EQC Output is measured from U5 pin 7. Controls are set as in Figure 1. Figure 4.
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Output is measured from U3 pin 1. Controls are set as in Figure 1. Figure 5.
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Figure 6.
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OC-1 Installation Procedures NOTE: The information included here is to aid the technician in setting up the OC-1 before doing any troubleshooting. These procedures are provided in more depth in the OC-1 Owner's Guide (P/N 176007). OC-1 Option Card Internal Protection Circuit Harness External Protection Circuit Harness Figure 7. OC-1 Option Card and Harnesses 1. Installing the Internal Protection Circuit Harness C. Slide the cover towards you and lift away from the controller. D.
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10A Flat side of barrel 10B 10C Figure 10. Internal Harness Connection E. Remove the lock nut and washer from the harness (Figure 10A). A. Turn the OC-1 PCB so that its component side faces you. F. Thread the harness through the rear panel (white connector first). B. Connect the harness to J1 on the OC-1 PCB (Figure 11). G. Turn the barrel connector so that its flat side matches the flat side of the hole in the controller.
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Figure 13. External Harness Connection C. Connect the harness's other end to the speaker terminals on your amplifier with either screw lugs (Figure 14A) or a banana plug (Figure 14B). Connect the red wire to the positive (+) terminal and the black wire to the negative (-) terminal. NOTE: Figure 15 shows a typical system hookup. Figure 14B. Banana plug Figure 14A. Screw terminal Figure 15.
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OC-1 Test Procedures Test Setup • Output mode switch should be set at normal Input Connections: Connect an oscillator to the positive (+) and negative (-) input terminals for Channels 1 or 2. These procedures assume that the person performing these tests is using test equipment with unbalanced inputs and outputs. See Figure 16 for connection information. Also, refer to Figure 15 for a system hookup diagram.
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Input Connections Audio Oscillator Audio Oscillator Output Connections Figure 16. Unbalanced Connections High frequency output connectors Input connectors Bass level control INPUT HIGH FREQ OUTPUT LOW FREQ OUTPUT LOW FREQ LEVEL . 0 INPUT LEVEL + SER. NO. D.O.M. – CH 1 + 4 3 +4 – CH 2 Input attenuator switches 2 1 PROTECTED BY U.S. PATENT 3,038,964 -18 + – + CH 1 +3 NORM 230V~AC 50/60Hz 12W LISTED 411F SUM – + CH 2 Mode switch .. –10 OUTPUT MODE . +4 . . .
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2. Frequency Response of LF Output 3. Protection Circuit Test A. Apply a 100 mVrms, 80 Hz signal to the controller's input terminals and reference your dB meter to this frequency. NOTE: Refer to Figures 13 through 15 and the installation instructions for connecting the external protection circuit harness. B. Measure the frequency response across the LF outputs according to the chart below. A. Connect a signal generator to the controller input terminals. Frequency (Hz) Response (dB) 20 -10.5 ± 1.
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Notes for Future Reference 15
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OC-1 Option Card Parts List OC-1 Packaging Parts List (Figure 16) Item Number Description Part Number Qty. Per Carton See Note 1 Cable Assembly 174147 1 1 2 Option Card PCB Assembly 145610 1 2,3 - Bag-Antistatic 174138 1 4 - Card-Owner's Registration 122157 1 4 - Envelope 122785 1 4 - Owner's Manual 176007 1 4 - Carton 145618 N/A 4 NOTES 1. The cable assembly consists of both the internal and external protection circuit harnesses. 2.
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Option Card (2) Internal Protection Circuit Harness External Protection Circuit Harness Cable Assembly (1) Figure 16.
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OC-1 Electrical Parts List Resistors Reference Designator R1-4 R6,7,41,75,76 R8,39 R9,10,12,14 R11,17 R13,90,93 R15 R16 R18 R19,25,28 R22 R24 R26,29 R27,30 R32,37 R33,36 R34 R35 R38 R45 R48 R50 Description Part Number 475 KΩ,1%,1/4W, 52mm,MF 7.5 kΩ,1%, 1/10W,0805 100 Ω,1%, 1/10W,0805 200 kΩ,5%, 1/10W,0805 1 MΩ,5%,1/10W, 0805 10 kΩ,1%, 1/10W,0805 51 Ω,5%,1/10W, 0805 4.64 kΩ,1%, 1/10W,0805 12.4 kΩ,1%, 1/10W,0805 20 kΩ,1%,1/10W, 0805 41.2 kΩ,1%, 1/10W,0805 5.1 kΩ,5%,1/10W, 0805 7.
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Resistors (Continued) Reference Designator R52,58,64,65,69, 77,78,83,89,94 R54,62,63 R85 R88 R92 R95 Description Part Number Jumper-Chip,0805 133627 14 kΩ,1%, 1/10W,0805 26.1 kΩ,1%, 1/10W,0805 178 kΩ,1%, 1/10W,0805 1.
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Capacitors Reference Designator C1,2,57 C3 C4,7,13,27,28 C5,6,8,9,18,19, 23-26,38,39,59 C10 C11 C14 C15-17,20-22 C35 C42 C43 C48,51 C52,54,55 Description Part Number 3300 pF,10%,50V, X7R,0805 100 µF,20%,25V, 105,Electrolytic 10 µF,20%,16V, 105,Electrolytic .022 µF,10%, 50V, X7R,0805 22 µF,20%,25V, BP,EL 1 µF,20%,50V, 105,Electrolytic 100 pF,5%, 50V, Cog,0805 .047 µF,5%, 63V, 85,Box .18 µF,5%, 50V, 85,Box .027 µF,5%, 63V, 85,Box .47 µF,5%, 50V, 85,Box .22 µF,5%, 50V, 85,Box .
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SPECIFICATIONS AND FEATURES SUBJECT TO CHANGE WITHOUT NOTICE ® Bose Corporation The Mountain Framingham, Massachusetts USA 01701 P/N 174786 6/94: REV.