AustralianMonitor-DCM500-pwr-sm维修电路原理图.pdf

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1、 DCM500 Service Manual Product Description Set-Up/Test Procedures Component Lists Full Schematics PCB Overlays RadioFans.CN 收音机爱 好者资料库DCM Series Circuit Description The DCM series are power amplifiers designed for commercial installations. They can be used for either low impedance (4 ohm/8 ohm) or c

2、onstant voltage line speakers (100v/70v). These amplifiers can be mounted in a standard 19” equipment rack or they can be used on a shelf or table. The DCM series feature line level input (with parallel output) and are normally used with mixers, mixer amplifiers or other power amplifiers. The DCM se

3、ries will operate from mains voltage or 24VDC. The DCM series also feature a DC battery trickle charge facility, auto-sensing fan cooling, plus overload, short circuit and over temperature protection. Power Switch This switch controls the switching of AC power to the amplifier. A blue On LED will in

4、dicate whether the amplifier is switched on or off. This switch will not switch DC power on or off in DC operation. In DC operation mode, the amplifier is always on and the blue power LED will always be illuminated. If both AC and DC voltage supply are connected and the AC power switch is in the off

5、 position, the amplifier will continue to operate normally from the DC supply and the mains fail LED will indicate. Level Control The output level control is located in the centre of the front panel. It is a fully recessed screwdriver adjustable pot. Turning this pot cw will increase the gain of the

6、 amplifier. At maximum setting the input sensitivity is 300mV. The amplifier ships from the factory with the sensitivity set to 1V. Amplifier Status Display This VU meter indicates the output level of the amplifier. The sensing for the circuit is taken on the amplifier side of the output transformer

7、. The 0dB level is referenced to 100V. This is an RMS meter, not a peak meter. Protect The protect LED will illuminate when the amplifier cuts out because of either over current or high temperature. The amplifier will switch back on after approx 4 sec for an over current trip. The amplifier will swi

8、tch back on after the amplifier has cooled to 60degC for a thermal trip. Limiter The limiter is a hard limiter with an attack time of about 1msec. It is defeatable by removing the jumper on the solder side of the front pcb. This however is not recommended as voltage overload and speaker transformer

9、current saturation may cause the amplifier to cut out under normal program material. Current Limit and Setup Current limit is controlled by a microprocessor (PIC12C509A). The detection is done by sensing voltage across the emitter resistors. Trimpot P1 on the front pcb is accessible through the hole

10、 in the top right of the chassis return (only visible with the lid off). Turning the trimpot ccw will decrease the point at which the amp cuts out ie the amp will cut out earlier. (P1 resistance is increased.) To set the current limit: 1. Reset the trimpot P1 turning fully clockwise. 2. Connect the

11、amplifier to half its minimum load (10ohm for DCM500, 20ohm for DCM250, 40ohm for DCM120). 3. Run an rms 1kHz sine wave into the amplifier and set the input level so that you read 425mVDC (DCM250/500) or 825mVDC (DCM120) across the emitter resistor, measuring the side which has the higher current (m

12、easured as a voltage across the emitter resistors). 4. Turn the trimpot P1 ccw till the amplifier cuts out. The amplifier is set to the factory default. Thermal and Fan control and Setup RadioFans.CN 收音机爱 好者资料库The thermal cutout and fan is controlled by a microprocessor (PIC12C509A). The temperature

13、 is sensed using a 10k25degC NTC. The fan is normally off and turns on to full speed at 60degC. This temperature is fixed and not adjustable. The thermal cutout temperature is set using the trimpot accessible through the hole in the top left side of the chassis return (only visible with the lid off)

14、. Turning the trimpot cw will decrease the point at which the amp cuts out ie the amp will cut out earlier. Power Amp The power amplifier is a push pull single supply amplifier driven by a class A transformer coupled front end. The drive is provided by HEXFETs (RF9520/9530) into NPN BJTs (TIP35C). W

15、hen replacing the FETs it is recommended that you replace both FETs. The matching of these FETs determines the balancing of the emitter currents in the output devices. For optimum performance the emitter currents in each side should match to within 30% of each other. Bias Setup The amplifier is set

16、with a bais setting of 1mV measured across the emitter resitors. Bias is set using the trimpots located on the power pcbs on each side of the amplifier. Turning the trimpots cw increases the bias. If the HEXFETs have been replaced the resistor in series with the pot may need to be changed. Use a low

17、er value resistor if the bias cannot be turned off or a higher value if the bias cannot be turn on. AC Power Inlet The operating voltage is 230/240 VAC 50 Hz. The 3 pin IEC power inlet is located on the bottom left of the rear panel and accepts a standard mains power lead fitted with an IEC connecto

18、r. Before plugging in a power lead, please check the rear panel of the amplifier to ensure that the voltage switch is set correctly for your part of the world. The inlet is equipped with an in-built AC fuse containing the rated fuse and a spare. 24 Volt DC Power Inlet The DCM series feature optional

19、 24VDC power to run off a battery back-up if required. This is connected via the rear binding posts. The front panel Power Switch will not switch DC power on or off in DC operation. In this mode the amplifier is always on. The trickle charge resistor across the diode is a 47ohm/5watt wire wound resi

20、stor. The maximum trickle current is 300mA supplied from internal 35V rails. 230V/240V Slide Switch The operating voltage of the amplifier is user selectable between 230V and 240V via a slide switch located on the center of the rear panel. This switch should be set to match the AC voltage of your co

21、untry. The mains transformer is wound with a 230V winding plus a 10V winding internally connected. Speaker Output Terminal Strip The screw terminals located on the top left of the rear panel allow access to the direct speaker outputs of the amplifier. Reading from left to right the terminals are: CO

22、M Common or “-” for low impedance speaker loads (4 or 8 ohms) 4 Positive “+” for 4 ohm speaker loads (use with common) 8 Positive “+” for 8 ohm speaker loads (use with common) DCM120 only COM Common or “-” for 70v or100v speaker loads 70 Positive “+” for 70v line speaker loads (use with common) DCM1

23、20/500 only 100 Positive “+” for 100v line speaker loads (use with common) Please ensure that the correct “Common” is used. Low impedance and 70/100v loads can be used simultaneously but please pay careful attention to the overall speaker load. Note: The minimum impedance (or maximum load) at 100 vo

24、lt line should be no less than DCM120 80 ohms DCM250 40 ohms DCM500 20 ohms XLR Audio Input and Parallel Output The DCM series includes both male and female 3 pin XLR connectors per channel. While the female is normally used as the input to the amplifier, both XLRs are connected in parallel so eithe

25、r will work. The XLRs inputs are transformer balanced and wired as: Pin 1: Shield. Pin 2: Hot, +, Positive Pin 3: Cold, -, Negative Fuse Sizes (DCM120) Mains: 230 VAC 4 Amperes Slow Blow HRC 20 x5mm DC: 10 Amperes Slow Blow HRC 20 x5mm (DCM250) Mains: 230 VAC 6.3 Amperes Slow Blow 20 x5mm DC: 2 x 10

26、 Amperes Slow Blow HRC 3AG (DCM500) Mains: 230 VAC 10 Amperes Slow Blow HRC 20 x5mm DC: 2 x 35 Amperes Slow Blow 3AG TESTING PROCEDURE OF DCM 120/DCM 250/DCM 500 I. PRE-TESTING (of complete sets). Check 1.1 All screw for tightness (Bridge rectifier and transistor bolts) 1.2 Earth Connection for good

27、 contact (solder and crimpling) 1.3 This setup has signal input to the Amplifier through male (XLR) 1.4 Check with Multimeter that there is a DC resistance of about 250 between Pin2 & Pin3 of each of XLRs. Also between (Pin 1 & Pin 3) and (Pin1 & Pin2). There should be very high resistance. (IE: no

28、reading). 2. Electrical Check 2.1 Fuse Check: DCM 120 DCM 250 DCM 500 Mains fuse: 4AT 6.3 AT 10 AT DC fuse: 10AT (x1) 10AT (x2) 35AT (x2) 2.2 Connect the Amplifier to the setup (Variac voltage = 0V) set all presets on front board (only) fully clockwise, voltage selector switch to 230V 2.3 Slowly inc

29、rease the input voltage to 230V, keep watching the input current should not exceed 0.1A for DCM-120, 0.1A for DCM-250, 0.1A for DCM 500. 2.4 Check and reset if necessary all emitter resistor voltages with the help of preset. (Each emitter resistor voltage should be between 0.5 mV to 0.8 mV ) 2.5 Che

30、ck DC voltage Main rail = 33V 7815 input = 30V 7815 output = 15.5V 2.6 Give input signal of 500 mV to get outputs as follows ( 4 output load)/ 22V for DCM 120, 32VAC for DCM250, 44.7VAC for DCM 500. Check 100V O/p at 100vV line, Remove the input signal II. FINAL TESTING (This setup should have signa

31、l input to Amplifier through female (XLR) (The limiter link should be out of circuit initially.) 1. Connect the Amplifier to the setup, set voltage selector switch to 240V 2. Switch ON the set to 240VAC. 3. Slowly increase the input signal (of 1kHz) keep watching the 24dB LED, it should glow at appr

32、ox 9V output. Increase the input signal to get 70VAC output. 4. Check Dc voltage of all emitter resistors, Minimum value should be within 30% of the maximum value. 5. Slowly increase the input signal, keep watching the 0db LED, it should glow at 100V 5V output voltage. 6. Set 100V 1kHz as 0db refere

33、nce. Change frequency to 10kHz check dB level drop. It should be 2.5dB 0.5dB. 7. Change the frequency to 1kHz, reduce signal level to get 10VAC output. Half the output load. 8. Overload setting: - Check the DC voltage at the emitter resistors having the maximum voltage value. Increase input signal t

34、o get 820mV for DCM 120, 425mV (for DCM250 & DCM 500). Turn preset (P2) anticlockwise such that it just mutes the output signal and signal returns back slowly after 2 seconds. 9. Reduce the signal & re check whether the signal mutes at the corresponding above stated voltages. 10. Again make the outp

35、ut load to original full value. Turn volume preset fully anticlockwise, set input signal strength to 1V, set volume preset clockwise to get 100V output. 11. Set input signal strength to get output 110V VAC. Insert limiter link, the signal should reduce to 100V 5V. 12. Remove the input signal and che

36、ck noise. It should measure less than 25mV. III. THERMAL & SOAK TEST 1. Connect the Amplifier to the setup : Output load = 4 Output Voltage: (DCM 120): 14V. (DCM 250):20V. (DCM 500): 40V 2. Set the Amplifier thermal cut off temperature at around 105C with the help of preset P4. 3. Leave the unit “ON

37、” (with lid fixed, if possible) for 24 hours. IV. Sound Test/Listening test. 1. Switch On the set. Check for any switch on thump. 2. Connect CD player to the input, listen for irregularities if any. 3. Switch off the set check for switch off noises. 12345678ABCD87654321DCBATitleNumberRevisionSizeA3D

38、ate:6-May-2003 Sheet of File:C:DCM ManualsCD6203-1.DDBDrawn By:C80.15uS1F335AF110AF235AD140AC3C4C2C1BR1T1R247RR14K7R3100RD312VD2RY1BR3C54u7C64u7C710uV1BC639C54321X11SBG-+24VBATTERY+35VDC240AC IN10000UX1X4X2X3X5X6X7123X8123CD6203-1DCM500 POWER SUPPLYPCB6203212345678ABCD87654321DCBATitleNumberRevision

39、SizeA3Date:8-May-2003 Sheet of File:C:DCM ManualsCD6201-12.DDBDrawn By:R42B10RR39B4K7R370RD4V16R39A10RR400RR38B47kR38A47kD2AD2BR1B220RR1A220RD3BD3AR11B4K7R11A4K7V3BBC556V3ABC556T2IC1A78L05C1B820PR36B500RD1BR6B150RR15BR22R14B2K2R13BR22R12B2K2R15AR22R14A2K2R13AR22R12A2K2C1A820PR6A150RD1AR36A500RV2BV2A

40、V5BV5AV4BV4AV1BV1AR7B10RR7A10RR8B470RR8A470RR9B1KR9A1KR5B150RR5A150RR4B1KR4A1KR3B220RR3A220RR2B220RR2A220RR10A1KR10B1KIC1B78L05V7AV8AR18A2K2R19AR22R20A2K2R21AR22V7BV8BR18B2K2R19BR22R20B2K2R21BR22V6AV6BR17BR22R17AR22R16A2K2R16B2K2V9AV9BR23AR22R23BR22R22A2K2R22B2K2R40B1KR41A10k NTCR41NOT USEDCX4 TO FA

41、NX3 TO PCB6200 X2X2 TO PCB6200 X1X1 TP PCB6203PCB6202X4 TO FANX3 TO PCB6200 X4X2 TO PCB6200 X3X1 TO PCB6136PCB6201R34 =2K2R24,R26,R28,R30,R32,R35 = 0.22RR25,R27,R29,R31,R33,V10-V15 = TIP35CDCM500PCB6202PCB6201CD6201-1DCM500 POWER PCBFAN21X45543X321X354321X154321X2FAN21X434X3TIP41C24V6535V21X3321X154

42、31X22+35V+35VSBG1100VACCOM11 X TIP35C11 X TIP35C70AC4 OHM212345678ABCD87654321DCBATitleNumberRevisionSizeA3Date:6-May-2003 Sheet of File:C:Protel FilesCDTRAXCD6200-14.DDBDrawn By:VDDP410KVDDR511KR421KD27D13VCCV6BC546R5510KR5610KIC2BLM358VCCVCCAGNDAGNDAGNDVDDR3110kR3010KVCCR2910KV5BC546C1122uVDDIC578

43、05VCCVCCVDDR3610KR1310KV7BC546C334u7R531KC52u2P247KR12100RC310uR11390RR101KR95K6D2D1R272M2R16 2M2R1747KR1422RC184u7C16100uC15100uR3422KR3322KD4C8100PC23100PC62u2C1947uV3BC54612356784910111214151613IC3ASA571C172u2C1447PC1347PR28100KR15100KC122u2C102u2R2510KR2410kR2310KR2210kR2139kR2010kR19100KR181KIC

44、4BLM833-BIC4ALM833-AC42u2C7100uIC17815P12KC22u2C12u2V2BC639V1BC639T1BT1AR8100RR7100RR6680RR5680RR410KR310KR268KR168KIC2ALM358R35 33KLK2LK30RC9.47uC264u7LK40RVDD1GP52GP43GP34GP25GP16GP07VSS8IC6PIC12C509D26D24D23D22D21D20D19D18D17R481KR4910KLK60RR461K2R452K7D25R41D31C354u7VCCR43470RR441KC324u7V4BC556D

45、10D16V8BC556R2610KVCCV9BC556R32470KC2047uPROTECTDesc2.3.4.5.6.7.PinGP5-IN = THRML SENSGP4-IN = FAN SENSEGP3-IN = I LIMITGP2-OUT = PRTCT/MUTEGP1-OUT = FAN CONI/OPowerCurrent LimitFan ControlThermal SenseProtect/On IndicatorBattery IndicatorVU DisplayMute/Limiter/DriveMicroprocessorX4/1X2/6(N/C)IC6/P2

46、IC6/P3X4/3X2/4FAN CONTROLPOWERX2/5X4/4IC6/P5IC6/P6AGNDIC6/P7IC6/P4IC6/P5(N/C)DX4/2X4/6X3/1X3/3X3/5X3/2X3/4X1/3X2/2X2/1X1/2X1/1X4/5GND8V2SBG116VDCX51DCM DRIVERCD6200-1X2/3LN3915-21-15-9-6-30+3DB101112131416181428765931715-12-18-25IC7X1/4X1/5MAINSFAIL*R41=15K=DCM120/500R41=12K=DCM 250GP0-OUT = 1/2VCC

47、CONDCM500 Power Supply Components ListDesignato Part TypeDescriptionManufacturers codeBR1KBPC3504Bridge recitfier 600V/35A2134800356BR3KBPC3504Bridge recitfier 600V/35A2134800356C115000uFElectrolytic Capacitor 50V2121250153C215000uFElectrolytic Capacitor 50V2121250153C315000uFElectrolytic Capacitor

48、50V2121250153C415000uFElectrolytic Capacitor 50V2121250153C54u7Electrolytic Capacitor 50V2121250479C64u7Electrolytic Capacitor 50V2121250479C710uElectrolytic Capacitor 50V2121230100C80.15uMetalised Poly Capacitor 275V2124290158D140AStud Mount Rectifier Diode 40A2135940100D21N4007Rectifier Diode21334

49、40007D312VZener diode 1W 12V2136010120F1*Fuse, refer user manualF235AFuse, 35A 3AG2541120350F335AFuse, 35A 3AG2541120350R14K7Resistor, metal film .5W9111590472R247RPW5 Wire Wound resistor 5W2111450470R3100RPW10 Wire wound resistor 10w2111460101RY1RelayRelay 12V 16A SPDT2522220793S1SwitchRocker Switc

50、h DPST2511210155T1Power transformer2651991355V1BC639Transistor TO922144200639DCM Series Drive Stage Component ListDesignato Part TypeDescriptionManufacturers CodeC12u2Electrolytic Capacitor 35V2121260229C102u2Electrolytic Capacitor 35V2121260229C1122uElectrolytic Capacitor 35V2121250220C122u2Electro