Bose-500PM-spk-sm维修电路原理图.pdf
《Bose-500PM-spk-sm维修电路原理图.pdf》由会员分享,可在线阅读,更多相关《Bose-500PM-spk-sm维修电路原理图.pdf(18页珍藏版)》请在收音机爱好者资料库上搜索。
1、Model 500PM LoudspeakerService Manual1998 Bose CorporationPart Number 197275 REV 00RadioFans.CN 收音机爱 好者资料库2CONTENTSElectrostatic Discharge Sensitive (ESDS) Device Handling . 3Warranty Information. 3Specifications. 4Theory of Operation, Model 500PM Loudspeaker SmartProtect Crossover PCB. 5Disassembly
2、/Assembly Procedures . 6-8Figure 1. Model 500PM Loudspeaker Driver Wiring Diagram. 7Test Procedures . 9Figure 2. Model 500PM Loudspeaker Test Setup Diagram . 9Main Part List, Model 500PM Loudspeaker (see Figure 3) . 10Figure 3. Model 500PM Loudspeaker Exploded View . 11Electrical Part List. 12-13Pac
3、king List, Model 500PM Loudspeaker (see Figure 4) . 14Figure 4. Model 500PM Loudspeaker Packing View . 14Figure 5. Model 500PM Loudspeaker Crossover PCB Topside Component andEtch Layout Diagram. 15Figure 6. Model 500PM Loudspeaker Crossover PCB Bottom Side Etch Layout Diagram . 16Figure 7. Model 500
4、PM Loudspeaker SmartProtect Crossover Assembly Schematic Diagram. 17PROPRIETARY INFORMATIONTHIS DOCUMENT CONTAINS PROPRIETARY INFORMATION OFBOSE CORPORATION WHICH IS BEING FURNISHED ONLY FOR THE PURPOSE OF SERVICING THE IDENTIFIED BOSE PRODUCT BY AN AUTHORIZED BOSE SERVICE CENTER OR OWNER OF THE BOS
5、E PRODUCT, AND SHALL NOT BE REPRODUCED OR USED FOR ANY OTHER PURPOSE.CAUTION: The Model 500PM Loudspeakercontains no user serviceable parts. To preventwarranty infractions, refer servicing to warrantyservice centers or factory service.RadioFans.CN 收音机爱 好者资料库Note: This manual has been updated using i
6、nformation from supplement197275-S1. This affects part numbers for PTC1, PTC2 and PTC3.3(ESDS) DEVICE HANDLINGELECTROSTATIC DISCHARGE SENSITIVEThis unit contains ESDS devices. We recommend the following precautions when repairing,replacing, or transporting ESDS devices:Perform work at an electricall
7、y grounded work station.Wear wrist straps that connect to the station or heel straps that connect to conductive floor mats.Avoid touching the leads or contacts of ESDS devices or PC boards even if properly grounded.Handle boards by the edges only.Transport or store ESDS devices in ESD protective bag
8、s, bins, or totes. Do not insertunprotected devices into materials such as plastic, polystyrene foam, clear plastic bags, bubblewrap, or plastic trays.WARRANTY INFORMATIONThe Model 500PM Loudspeaker is covered by a 5-year transferable limited warranty.4SPECIFICATIONSExternal Dimensions, Single Speak
9、er,including grille:18.09L x 11.77D x 10.10H(45.95 x 29.90 x 25.65 cm)Weight:Packed Pair, 60lb (27.3kg)Shading Network Assembly:5.6uF capacitor with 0.13mH series inductor,33uF capacitor with 0.5mH series inductor, 33ufcapacitor with 3.9 parallel resistor and 0.8mHparallel inductor.Internal Cabinet
10、Volume:19 Liters netPort (each side):Flared slot port tuned to 58HzImpedance:6 nominal, 4.8 minimum from 20Hz to 20kHzPower Handling:200W (34.6Vrms) continuous per IEC-268-5.Sensitivity:85dB SPL 1W/1m, free-field, per IEC-268-5for octave band centered at 400Hz.SmartProtect:Turn on voltage of the tra
11、nsistorsof the electronic switch:1.5-1.8VrmsResistance prior to turn on:3On resistance:0.2Max audio voltage applied to speaker:70VrmsMaximum cont. sinusoidal current, 1Khz:3.6Arms 15%Maximum cont. sinusoidal current, 150Hz: 5Arms 15%Reset time:200-400msTime to trip, as a function ofspeaker current:D
12、C turn-off current:5ASpeaker CurrentI/ITime to Trip3.31-5ms30.8ms22s1.53s15THEORY OF OPERATIONModel 500PM Loudspeaker SmartProtect Crossover PCBNote: Refer to Figure 7. Model 500PM Loudspeaker SmartProtect Crossover AssemblySchematic Diagram, for the following explanation.The SmartProtect PCB is an
13、electronic switch, in series with the speaker, used to protectthe drivers from high current and power levels. It has a fast turn-on time of about 100milliseconds. At turn-on, current flows through R1, C1, D1, D2, C2, Q1, C3 and R18.Capacitors C2 and C3 form a virtual power supply which is used to po
14、wer theSmartProtect circuit to provide the bias to FETs Q8 and Q9, limited by the Zener diodeD6 to 10 V. Diodes D1 and D2 form a voltage doubler. Once C2 is charged, Q1 willconduct and provide a charge path for C3. Once C3 is charged, if the input audio voltagebecomes lower than 4V, Q1 will turn off
15、, and the charge on C3 provides a voltage used tooperate the circuit for up to 5 hours. PTC1 provides the current path if the speaker mustplay for a long time at very low volume when input AC voltage to the speaker is less then1.5V.Resistors R16 and R17 form the current sensor. It allows the circuit
16、 to sense the speakercurrent and protect it from the following types of the abuse:1. DC offset - when too high a DC offset level is detected one, of the two transistors Q6or Q7 will be turned on through resistor R19, thus tripping the monostable multivibratorQ2, Q3.2. Fast DC/AC transients - works t
17、he same way for both transient polarities, thresholddepends on the ratio of resistors R19 and R20.3. Thermal overload - When the AC current is too high for a prolonged time, transistor Q4turns on through resistor R13, tripping the monostable multivibrator Q2, Q3. The timeconstant of current integrat
18、ion depends on C6, R13 while the time constant of “memory” isdefined by R6 and C6. AC voltage divider R15, R14, and C7 defines the frequencydependent threshold of current protection.The protection portion of the circuit works as follows: When monostable multivibrator Q2,Q3 is tripped, by one of the
19、above conditions, transistors Q2 and Q3 turn on, reducingthe gate voltage of Q8 and Q9 to zero, and shutting them off. At this moment the speakerload is disconnected from the amplifier. During the off cycle, capacitor C4 is chargingthrough resistor R3, and when the charging is completed, Q2 and Q3 w
20、ill shut off again,turning Q8 and Q9 back on, and allowing the speaker to operate again. If the overloadcondition persists, the monostable multivibrator will trip the circuit again, and shut off thespeaker again. Duty cycle depends on the current through the speaker.Troubleshooting1. If PTC1 is open
21、, the unit will not play at low volume levels (Vin1.5 V) when thesystem is first turned on, but as the volume is increased, the SmartProtect circuit will turnon, and the speaker will operate. It will then operate for approximately 5 hours, until thecharge on C3 is too low to keep the circuit running
22、, and then the speaker will shut offagain.2. If either R18, R1, D2 is open, or D1 is shorted there will be no charge of the virtualpower supply formed by C2 and C3, and the circuit will never turn on. The symptom willbe that the speaker will play at low volume levels, but as the volume is turned up,
23、 thespeaker will stop operating. This may also happen if for any reason Q7, Q8 or any othercomponent in the circuit fails, and internal safety “watchdog” C5 turns the Q3 onpreventing the Q8 and Q9 from being overheated.Shading NetworkThe shading network consists of one 5.6uF capacitor, one RXE040 PT
24、C, and one 0.13mHinductor across the two front array drivers, one 33uF capacitor, one RXE040 PTC and one0.5mH inductor across the driver nearest the port and a trap filter consisting of a 3.9resistor, a 33uF capacitor, and a 0.8mH inductor. The inductors are iron core.6DISASSEMBLY/ASSEMBLY PROCEDURE
25、SNote: Refer to Figure 3. Model 500PMLoudspeaker Exploded View, for thefollowing procedures.1. Grille Removal1.1 Using your fingers, grasp the grille (14)edge nearest the curved end and gentlypull the grille away from the cabinet until itcomes free.1.2 Grasp the opposite edge of the grilleand gently
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- Bose 500 PM spk sm 维修 电路 原理图