Bogen-CT35-pa-sm维修电路原理图.pdf

A DIVISION OF LEAR SIEGLER, INC. AMPLIFIERS Models CT 35/60/100Bogen Acousta-Master CT Series Public AddressAmplifiers are versatile, silicon-transistor preamp-mixer-amplifiers designed for professional-quality sound reinforce-ment requirements. Model CT-35 is rated at 35 watts,Model CT-60 at 60 watts and CT-100 at 100 watts output.Four high-impedance microphone inputs are provided,each convertible for use with low-impedance microphones.A simple modification converts inputs to low-impedanceunbalanced; balanced inputs require accessory plug-intransformers. Two mic inputs and one auxiliary input maybe remotely controlled or muted for announcements overanother mic channel. The same two mic inputs may be con-verted to accept a magnetic source, i.e., turntable or tapeplayer. Two auxiliary inputs with fader control are pro-vided, as well as a bridging input.Acousta-Master amplifiers feature the Bogen built-inacoustic equalizer filter circuit, which provides a means ofboosting or attenuating any of five selected frequencies tosuit individual room acoustics. An electronic limiter circuitprovides uniform output regardless of wide variations in theinput level. With this capability, all paging calls can betransmitted with the same volume and clarity.An output terminal strip and connectors at the rear ofthe amplifier provide standard speaker impedance taps, aswell as connections for 25volt or 70-volt balanced lines.There is also a bridging output for feeding a tape recorder.Bogen accessories provide the amplifier with telephoneline input and output connections, remote volume control,and channel override facilities. Further information iscontained in the Accessories section.The amplifier operates from a 105-125 volt, 50/60 Hzsource. A three-prong line cord provides automatic ground-ing when connected to a three-wire power outlet. Thepower line is protected by a circuit breaker, and the outputtransistors by a thermal overload device, which shuts offthe unit when the temperature of the heat sink risesexcessively.INSTALLATIONUNPACKINGThe amplifier was carefully checked before leavingfactory. Inspect shipping container and unit carefully forindications of improper handling. If the unit has beendamaged, make an immediate claim to distributor fromwhom it was purchased. If the amplifier was shipped toyou, notify transportation company without delay andplace your claim.POWER AND GROUNDINGThe ac line cord has a three-prong plug which should beplugged into a three-wire grounded, 120 volt, 60 Hz outlet.As it is important to ground the amplifier, where a three-wire outlet is not available, use an adapter (e.g., LevitonNo. 5017) and connect the grounding pigtail to the screwsecuring the wall plate. If the wall plate screw is not ground-ed, connect a wire from the GND terminal of the amplifierto a suitable ground.AUXILIARY POWERThe auxiliary power receptacle on the rear chassis (seefigure 1) is a three-wire grounded outlet, which can supplypower to accessory sound equipment. When connectingassociated equipment with a three-prong cord, appropriategrounding is accomplished when the amplifier line cord isproperly grounded.Use the ON/OFF switch on the phonograph for turningoff a record player connected to the auxiliary receptacle, asuse of the amplifier power switch could cause flats todevelop on the idler wheel of the phonograph.Be sure that the auxiliary components donot draw more than 250 watts on the CT35and CT 60, and 500 watts on the CT1 00.Prmted i n USA 8104 54-5629-l 4RadioFans.CN 收音机爱 好者资料库TECHNICAL SPECIFICATIONSICT35ICT60ICT100IPOWER OUTPUT (RMS at 1000Hz)FREQUENCY RESPONSEREGULATION35 wattsI60 wattsI100 watts less than 2% total harmonic distortion50Hz to 15kHz 2dB2 dBHUM & NOISE (below rated output) MIC, 60 dB for both low and high impedance; AUX 70 dB; Fundamental, 80 dBSENSITIVITY (for rated output) Hi Z MIC, 3 mV; Low Z Bal MIC, 0.3 mV; Low Z Unbal MIC 0.3 mV; Bridging Input,30 mV; AUX 150 mVOUTPUTS 4, 8 ,16ohms 8,16ohms25V CT 25V CT7ov 7ovI4, 8, ,16ohms25V CT7ovIBridging, 30 mV; Tape, 0.68 V. TAPE/BOOSTER/BRIDGING outputs,500/6OOa telephone line input or output with WMT-i optional accessory.IOUTPUT CONNECTIONSI2 Quick disconnect type sockets with plugs provided, in addition to screw-typeterminals, tape/booster jack, and provisions for WMT-1.IINPUTSCONTROLS4 Hi Z MIC inputs, each convertible to Low Z Bal or Unbal MIC; 2 AUX inputs withfader control; MIC 1 & 4 convertible to MAG input; Bridging input; 500/600 ohmtelephone line with optional WMT-1 accessory; 3 inputs for remote volume control.4 MIC Volume, AUX 1, AUX 2-fader, MASTER VOLUME, 5 Equalizer Filter SlideControls. 1 Compressor. 1 Power Switch.FILTER CONTROL ACTION 10dB Bvariation at the following frequencies:80 Hz, 300 Hz,1 kHz,3kHz,10kHz.COMPRESSION 5 milliseconds attack time, 2 seconds decay time, max. compression 30 dBLINE FUSINGI Resettable Circuit BreakerISEMICONDUCTORSPOWER CONSUMPTION0.93 A Hold 1.65 A Hold 2.5 A Hold18silicon transistors 18 silicon transistors 20silicontransistors2 Zener Diodes; 8 Silicon Diodes (10 in CTl00)120 V AC, 50/60 HzDIMENSIONSSHIPPING WEIGHT0.86A, 96W16-3/8”W x 12”D x 4”H(41.6cm x 32.4cmx12.lcm)19 lbs. (8.6 kg)1.6A, 170w 2.9A, 300W16-3/8”W x 13 3/4”D x 4 3/4”H(41.6cm x 34.9cm x 12.lcm)221bs. (9.9 kg) 26 lbs. (11.8 kg)INPUT CONNECTIONSHIGH IMPEDANCE MICROPHONES: The amplifier isshipped in a configuration for direct connection of highimpedance microphones (50k ohms) to the four MIC inputreceptacles of the amplifier. The microphone lead should bea single-conductor shielded cable under 35 feet long andterminated in a Cannon XLR-311C connector (Bogen PartNo. 85-0124-01) as shown in figure 2.In the event jumpers on the printed circuit board havebeen rearranged and must be returned to the configurationfor direct connection of high impedance microphones,connect the two jumpers involved as follows: the firstjumper between terminals 11 and 19, and the second be-tween 8 and 18. Three jumpers are not involved and arestored by connecting both ends to an assigned terminal: thefirst jumper on terminal 20, the second on 24, and the thirdon 25.BALANCED LOW-IMPEDANCE MICROPHONES: Low-impedance accessory transformers are required to permitthe amplifier to accept inputs from microphones rated from50 to 600 ohms. Before connecting microphone, insertappropriate plug-in transformers and reset jumpers adjacentto transformer sockets as described in the Accessories sec-tion. Use a two-conductor shielded cable for the + microphone lead, terminated in a Cannon XLR-311C connector,as shown in figure 3.,- 2 -RadioFans.CN 收音机爱 好者资料库SPEAKEROUTPUTSOCKETSTERMINALSCIRCUITTAPE/BOOSTER AUXBREAKERTAPEINPUTSIOUTPUTIIIIIWMT-1OUTPUTI IAUXPOWERIMPEDANCEREMOTE/PRECEDENCESELECTORTERMINALSBRIDGINGIIMIC INPUTSNote:Heat sink for Model CT-35HEAT SINKis an aluminum plate.Figure 1 - Rear Panel, CT-100UNBALANCED LOW IMPEDANCE MICROPHONES:Jumpers with push-on connector lugs are mounted on theprinted circuit board assembly for use in converting theMIC input channel circuits. See note 4 on the schematicdiagram, figure 6. To convert MIC 1 and 4 for unbalancedlow impedance use, connect jumper between pins 20 and2 1; to convert MIC 2 and 3, connect jumper between pins25 and 26. As shown in figure 2, connect a jumper betweenterminals 1 and 2 of the connector and wire microphone topin 3 of the plug.AUXILIARY INPUTS: Two auxiliary inputs are providedfor high-level, high impedance inputs. these may be used toconnect a radio tuner, tape recorder, or turntable utiliz-ing a ceramic cartridge. An input signal of 0.15 volts isrequired to obtain full output from the amplifier.Use single-conductor shielded cable terminated in anRCA phono plug for connecting auxiliary component. Ifhum is experienced after making connections, run a groundwire between the chassis of the auxiliary unit and the GNDterminal on the amplifier.BRIDGING: The amplifier may be bridged to a secondBogen CT amplifier to double the number of inputs. Con-nect a single-conductor shielded cable, terminated in anRCA phono plug at each end, between the rear panelBRIDGING receptacles of the two amplifiers. Any input toeither amplifier will then be fed through and available atthe output of both amplifiers. The amplifiers must eachWhen two amplifiers are bridged together,any adjustment of the MASTER, COM-PRESSION or Acoustic Equalizer controls inone amplifier will not affect the output ofthe other amplifier.:(CONNECTION SAME FOR MAG PHONO) XLR-311CBALANCEDLOW IMPEDANCE MICROPHONE XLR-311CJ2UNBALANCEDLOW IMPEDANCE MICROPHONE XLR-311Cfeed separate speaker systems.Figure 2 - Connecting Microphone Cable Connector-3-MAG PHONO: The output of a phonograph employing amagnetic cartridge may be connected to the MIC 1 and 4receptacles on the rear panel. Use a single-conductor shield-ed audio cable terminated in a Cannon XLR3 11C connec-tor as shown in figure 2 (connections same as high im-pedance mic). A magnetic tape head may also be connectedin this manner.Connect a single conductor shielded cable, terminated inan RCA phono plug at each end, between the rear panelBRIDGING receptacles of both amplifiers. This assures thatany input will have equal amplification.To provide the necessary equalization for magneticphono and tape head inputs, the Berg terminal jumpers onthe printed circuit board must be connected as indicated innote 3 on the schematic diagram. Connect a jumper be-tween pins 21 and 22 and between pins 23 and 24.AMPLIFIER 1GND COMI 25VCTAMPLIFIER 2GND COMl 25VCTOUTPUT CONNECTIONSSPEAKERS: For installations where speakers will be con-nected permanently, output connections are available onthe terminal strip at the rear of the amplifier for 4, 8, and16 ohm speakers and 25volt lines. Connections may bemade for an unbalanced line or for a balanced line with orwithout center-tap grounding. Make speaker line connectionsas shown in Table 1.Impedance indicated in Table 1 is also available at twospeaker sockets on the rear panel. Two quick-disconnectplugs (Bogen 85-0147-01) are furnished with the amplifierto make connections to these sockets. Wiring of the speakeroutput plug is shown in figure 3. When the speaker socketsare used, connect the wired plug to either socket. For un-1L+25VALL UNITSbAMPLIFIER 1 AMPLIFIER 2GND COM 1 l6n GND COM 1 16nCT60 AND CT 100A74-2031-01Figure 4 - Connecting Amplifiers in Seriesbalanced. 4, 8, 16 ohms and 25-volt operation, attach theimpedance selector lead to the speaker system impedanceBoth amplifier tone and master volume controls must beat the same setting to assure that each amplifier will shareterminal, and leave the link connected between COM 1 andGND terminals. A balanced output is available by removing thethe load equally.link.For 70 volt constant voltage systems, see Table 1. Fordetailed information see installation manual No. 54-5001,furnished with the amplifier.To minimize shock hazard, Class I wiring asdefined in local building codes should beused for 70-volt outputs. All other outputsmay use Class 2 wiring.CONNECTING AMPLIFIERS IN SERIES: Pairs of BogenCT amplifiers of the same power rating can be connected inseries to effectively double the power output into the samespeakers. See figure 4 for connection diagram. Be certain toremove the link between COM 1 and GND of amplifier No.2.F O R 70V OPERATlONzil-J=FOR 25V OPERATIONOR SELECTED IMPEDANCES-!3c-1-Figure 3-Speaker Output Plug WiringTAPE/BOOSTER OUTPUT: The amplifier may be used todrive a tape recorder or a booster amplifier. Connect apatch cord with an RCA phono plug from the TAPE/BOOSTER jack on the rear panel of the amplifier to theinput of the tape recorder or booster amplifier. The outputat this jack is controlled by the amplifiers volume andequalization controls.TAPE OUTPUT: A tape recorder may also be driven fromthe TAPE OUTPUT jack on the amplifier. In this case, theoutput is not subject to the master volume and equalizationsettings of the amplifier and is controlled at the taperecorder. A patch cord terminated in an RCA phono plug isconnected between the TAPE OUTPUT jack on the ampli-fier and the input of the tape recorder.WMT-1 OUTPUT: This receptacle is used to accommodatea Bogen accessory which provides connections to a 500/600-ohm telephone line.ACOUSTIC EQUALIZER: The Acoustic Equalizer permitsyou to “tune” the amplifier to the room in which thesound system is used, so that the amplifier will operate at asubstantially higher output before acoustic feedback oc-curs. Five slide controls, located on the front panel, boostor attenuate the output at five selected frequencies-80 Hz,300 Hz, 1 KHz, 3 kHz, and 10 kHz. Varrying room acous-tics or microphone placement may cause feedback or howl-ing at or near some of these frequencies. If so, feedback canbe greatly attenuated by setting the slide control for thatparticular frequency as described below.-4-TARI F 1-f-U ITPI IT CONNECTIONS._I_ . _. _. ModelsCT35 & CT100All modelsAllAllAllSpeaker Line4S2 Unbalanced4n Balanced8n Unbalanced8n Balanced16n Unbalanced16n Balanced25V Unbalanced25V Balanced25V Balanced, CT gnd.70V Unbalanced70V BalancedTerminal Connections *4n and COM 14n and COM 18n and COM 18n and COM 1160 and COM 116n and COM 125V and COM 125V and COM 125V and COM 1Pins 2 and 3Pins 2 and 3Other ConnectionsClose link between COM 1 and GNDOpen link between COM 1 and GNDClose link between COM 1 and GNDOpen link between COM 1 and GNDClose link between COM 1 and GNDOpen link between COM 1 and GNDClose link between COM 1 and GNDOpen link between COM 1 and GNDConnect jumper between 25V CT and GNDOpen link between COM 1 and GNDConnect impedance selector to COM 2Connect jumper between COM 2 and GNDConnect impedance selector to COM 2*Also see text under “Output Connections”ROOM EQUALIZATION: With speakers connected andone microphone in normal operating location, turn ampli-fier on and proceed as follows:1. Connect microphone to appropriate MIC input ofamplifier.2. Set all five acoustic filter controls to zero (centerposition).3. Turn MIC volume control half-way up and the threeother MIC volume controls to zero.4. Advance MASTER volume control slowly untilfeedback is heard.5. Note the frequency of the feedback tone, and de-termine which of the five selected frequencies on theAcoustic Equalizer is closest to it.6. Move the control determined in Step 5, above,down toward minimum until feedback disappears.7. Advance MASTER control again and note whetherfeedback is heard at another frequency.8. Adjust the appropriate filter controls until thisfeedback disappears.9. Continue to advance MASTER control and adjustindividual filter controls until MASTER control is at maxi-mum setting, consistent with a stable output withoutfeedback at any frequency.10. Output level reduced because of attenuating onefrequency may be partly restored by boosting the adjacentfrequency filter control toward maximum.If feedback is nor a problem, the controlsshould be used to improve the voice qualityand intelligibility of the paging sys