Dukane-1A803-pwr-sch维修电路原理图.pdf

EXTERNAL CONNECTIONSDUKANE MODEL 1A803 100-WATT POWER AMPLIFIERFUSE (A N D THERMOSTAT) -One 4-ampere slow-blow fuse protects the primary AC power circuit for this amplifier.I n addition,there is a temperature-controlled (thermostat) switch (S1) ) in the AC powercircuit and which is fastened to one of the large transistor heatsinks; any over-heatingof the output transistors will open the primary : power circuit, and the power circuit isclose d automaticallyy as the thermostat temperature comesINSTALLATION NOTES -The DuKane Model 1A803 100-Watt Power Amplifier providesinput, single-ended. See paragraph titled “INPUT LEVEL”down.full-rated output with 0.4 volton next page.Amplifier Ground- I t t is good practice to ground the amplifier chassis to the rack orconsole metalware which is, in turn,connected to conduit and electrical system ground(or coldwater pipe).To be sure grounding exists between the amplifier and the metal-ware, place an outside-toothed lockwasher under the head of one of the mounting screws.Clas s I I I wiring is permissible for 25-volt or 70-voltt level output (speaker line). A Cpower wiring must be Class I w i r i n g o n l y .EXTERNAL CONNECTIONS -Make ALL external connections to screw terminals on rear of amplifier.Connect AC powerto this amplifier AFTER external connections have been made and are checked to be freeof any short circuits.A conventional speaker system of up to 100 watts,including appropriate speaker-to-linematching transformers can be connected to this amplifier.See chart at top of next page.OUTPUT CONNECTIONS -I35Connect jumper wires between screw terminals25-VOLTOUTPUTand connect speaker line as shown at right246 246n 402-ig2ARadioFans.CN 收音机爱 好者资料库-70-VOLT SPEAKER LINE25-VOLT SPEAKER LINESPEAKER POWER DUKANE TRANSFORMER SPEAKER POWERDUKANE TRANSFORMERLEVEL PART NO. LEVEL PART NO.15 to 50 watts 710-3070 5 to 20 watts710-30775 to 30 watts 710-30711 / 2 2 to 2 watts710-30751 / 2 2 to 4 wattsl/1 6 to l/2 wattINPUT LEVEL -Not more than 0.4 volt rms (sine wave) input is required to obtain full 100watts of output power with this amplifier.,However,it is recommended that, in order toaccommodate the complex wave form of program material,th e input should be lowered 8 dB(to 0 VU) for actual amplifier installation and operation.Set INPUT LEVEL potentiometerfor 0 level indicated on VU meter (on 25-volt line. IO volts rms sine wave - on 70-voltI ine, 28 volts rms).hput connections are made at screw terminals labeled “IN and “COM”, shield to “COM”.COM to GND -In some instances,it will be found desirable to disconnect the jumper be-tween “COM” and “GND” on the input terminal strip - amplifier common connected throughshield to preamplifier ground instead - to reduce any hum pick-up.ALSO see paragraphon the front of this sheet titled “Amplifier Ground”.BRIDGE IN COM GNO DCIIOUTPUTHIGH-IM PEDANCE INPUT C ONNE CTIONS.BRIDGING -An appropriate resistor may be connected between the screw terminals labeled“BRIDGE” and “IN ” in instances where input level is too high to be easily reduced byINPUT LEVEL potnitometer.A lOO,OOO-ohm, l/2-watt resistor will reduce input level by6 dB; a I-megohm resistor would be inserted where input might exceed 10 volts.AC POWER CONNECTIONS -IMPORTANT -Before connecting AC power to this amplifier, BE SURE that correctoutput load (speakers correctly matched to speaker line) and inputconnections are properly made to terminals on this amplifier.AC power wiring must be Class I wiring ONLY.primary taps for IlO-volt line,Power transformer in this amplifier has117-“online and 125-volt line. As supplied. the 117-volt tap is connected.However,if line voltage is more than 120 volts, disconnect thecircuit breaker white wire connected at terminal lug for yellow-black transformer tap,and connect circuit breaker wire to lug for red-black transformer tap.If line voltageis less than Ii 5 volts,connect circuit breaker wire to white-black transformer tap.DC TERMINAL -Auxiliary power is available for external preamplifie,r, of 28 volts DCat 50 milliamperes.aRadioFans.CN 收音机爱 好者资料库