NAD-M25-pwr-sm 维修电路原理图.pdf
《NAD-M25-pwr-sm 维修电路原理图.pdf》由会员分享,可在线阅读,更多相关《NAD-M25-pwr-sm 维修电路原理图.pdf(46页珍藏版)》请在收音机爱好者资料库上搜索。
1、SERVICE MANUALSERVICE MANUALM25 C/AHMODEL :M3SERVICE MANUAL NAD 2005NAD ELECTRONICS INTERNATIONALTORONTOM25 C/AHSEVEN CHANNEL AMPLIFIERM25 C/AHSEVEN CHANNEL AMPLIFIERSEVEN CHANNEL AMPLIFIERRadioFans.CN 收音机爱 好者资料库CONTENTSFRONT PANEL/REAR PANELVIEW? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
2、? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?3SPECIFICATIONS? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 4ALIGNMENT PROCEDURE/ALIGNMENT POINTS? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?5-6WIRING DIAGRAM? ? ? ? ? ? ? ?
3、 ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?7SCHEMATIC DIAGRAM? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?8-16PCB LAYOUT? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
4、 ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 17-23ELECTRICALPARTS LIST? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?24-40EXPLODED VIEW? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
5、 ? ? ? ? ? ? ? ? 41-44EXPLODED VIEW PARTS LIST? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?45PACKING DIAGRAM? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?46SERVICE SAFETY PRECAUTIONS1
6、. Replacing the FusesCAUTION: FOR CONTINUED PROTECTION AGAINST THE RISK OF FIREREPLACE ONLY WITH SAME TYPE OF FUSE.REFERENCE NO.PART NUMBERDESCRIPTIONRear PanelAH20-11203-10MDAT20AL/250VC20-12103-20MDAT10AL/250VAMP BoardF101/F10220-12632-00T6.3AL/250VPSU BoardF201-F20420-12162-01T1.6AL/250VNOTE:*AH
7、: North American version only*C: European version only2. Safety-check out (North American model only)Before returning the product to the customer, make leakage current orresistance measurements to determine that exposed parts are acceptablyinsulated from the supply circuit.Parts marked with the symb
8、olare critical with regard to the risk of fire andelectric shock.Replace only parts recommended by the manufacturer.- 2 -RadioFans.CN 收音机爱 好者资料库FRONT PANEL / REAR PANEL VIEWFRONT PANEL CONTROLS1. POWER SWITCH2. POWER INDICATOR3. SOFT CLIPPING INDICATOR4. PROTECTION INDICATOR1. AC INLET2. INPUT JACK3
9、. LEVEL CONTROL4. SPEAKER TERMINALS5. AUTO TRIGGER SWITCH6. 12V TRIGGER INPUT7. SOFT CLIPPING SWITCH8. MAINS FUSE9. GROUND TERMINAL- 3 - 4 -SPECIFICATIONSCONTINUOUS AVERAGE POWER?160 W (22.0 dBW)OUTPUT INTO 8 OHMS OR 4 OHMS(Min. power per channel, 20 Hz 20 kHz, bothchannels driven, with no more than
10、 rateddistortion)Rated Distortion?0.03%(THD 20 Hz 20 kHz)Clipping power?180 W(maximum continuous power per channel).IHF dynamic power(Maximum short term power per channel)8 ohms:?220 W (23.4 dBW)4 ohms:?385 W (25.9 dBW)2 ohms:?485 W (26.9 dBW)Damping factor180(ref. 8 ohms 50Hz)Input ImpedanceR = 1 M
11、ohmsC = 180 pFInput sensitivity (for rated output into 8 ohms)1250mV+/-50mVVoltage gain29 dBFrequency response 20 Hz 20 kHz?0.2 dB- 3dB at 3 Hz/70 kHzSignal / Noise ratio, A-weighted96 dB ref. 1 W118 dB ref. 160WDIMENSIONS AND WEIGHTSNet Weight44.5 kg (98.0 Ib)Shipping Weight53 kg (116.7 Ib)Dimensio
12、n (WHD)435 200 465.6mmALIGNMENT PROCEDUREA. THERMAL SENSE ADJUSTMENTThis adjustment should be always done when the M25 is cool condition. (That means thetemperature inside the unit should be almost same as the ambient temperature.Connector P208B that connects the transformer and power board should b
13、e removed toavoid that the Idling current heats up the unit excessively) At ambient temperature of 25 Cdegrees and when the unit is just turned on (still in cool condition), adjust the potRV103(as marked as “Thermal Sense ADJ” in below drawing) for a voltage between theTHERMAL TEST POINT and AGND to
14、 be 750mV+/-10mV. If the ambient temperature isdifferent, the voltage setting should be changed by 20mV per degree difference. So at20C degrees, the voltage should be 850mV+/-10mV; and at 30C degrees, the voltageshould be 650mV+/-10mV, etc.B. DC OFFSET VOLTAGEThe DC OFFSET between OFFSET Test Point
15、and AGND must be within 0+/-3mV. If itsfound to be out of this range, change the TL084BCD to one selected for low offset voltageto meet the requirement.C. IDLING CURRENTThe idling current in the output stage of the poweramp should be set to 40mA+/-10mAper pnp-npn transistor pair( This means the mid
16、point voltage is 17.6mV with down limit of13.2mV and up limit of 22mV). The alignment procedure is: At first, adjust RV102 (Markedas “Idling Current ADJ” in the drawing below) for a voltage of 17.6mV +/- 1mV betweenTest point 1 and 2. Then preheat the unit for 5 minutes, let idling current settled a
17、nd thenreadjust to 17.6mV +/- 1mV.Pls note:1.The idling current must be adjusted when all modules are assembled into the unit.2.Though the idling current is set as 17.6mV +/-1mV during the adjustment, due to theinfluence of varied ambient temperature and mains voltage etc., the idling current will d
18、riftafter some time. During the normal checking of idling current in the service field, itsacceptable as long as the voltage is in the range of 13.2mV22.0mV.D. ISC Current sense zero-set.The ISC current-sensing voltage at no signal should be 0mV+/-50mV. During factoryalignment, it is set to 0mV+/-10
19、mV . That is to adjust Pot RV104 (as marked as “ISCSENSE ADJ” in the below drawing) to get a voltage between the “ISC SENSE TESTPOINT” and AGND to be 0mV+/-10mV.(Pls note the ISC should be adjusted when all modules are plugged in. Its not possible to get0mV +/-10mV if any of the modules are removed.
20、)E. Fan Cut Off Point AdjustmentCheck the Fan sense voltage first. Turn Pot RV201 to the end clockwise and confirm TP2of J201 is in negative voltage. Run the unit to heat it up and drive the fan to start turning,- 5 -for example, all 7 channels at 50W/4ohms for 10 minutes or 5 minutes or even less (
21、aslong as the fan can starts turning). Turn off the signal but still keep the unit operating for 1minute. Then run all 7 channels at 1kHz, 0.25W at 4 ohms load, monitor the voltage atTP1 of Pot RV201. Adjust RV201 to get the voltage from negative to positive to ensurethat the Fans are turned off. Th
22、en run all 7 channels at 1kHz, 0.5W at 4 ohmsload, monitor if the voltage at TP1 of Pot RV201 is negative, if not, adjust Pot RV201 justto the point that TP1 changes from positive to negative (to get the fans just start turning).Finally, turn off the signal and monitor if fans stop turning within ab
23、out 30s Max.- 6 -ISC SENSE ADJAGNDACINACINACOUTACOUT+5V+5VRELAYRELAYSC NPNSC PNP+18V-18V+70V-70VPROTECTSENAC OFF+62V-62V-62VAGNDAGNDAGNDISC TRIGAGND+62V+18V-18V+70V-70VPROTECTSENAC OFFSC NPNSC PNP+62V-62V-62VAGNDAGNDAGNDISC TRIGAGND+62V+18V-18V+70V-70VPROTECTSENAC OFFSC NPNSC PNP+62V-62V-62VAGNDAGND
24、AGNDISC TRIGAGND+62V+18V-18V+70V-70VPROTECTSENAC OFFSC NPNSC PNP+62V-62V-62VAGNDAGNDAGNDISC TRIGAGND+62V+18V-18V+70V-70VPROTECTSENAC OFFSC NPNSC PNP+62V-62V-62VAGNDAGNDAGNDISC TRIGAGND+62V+18V-18V+70V-70VPROTECTSENAC OFFSC NPNSC PNP+62V-62V-62VAGNDAGNDAGNDISC TRIGAGND+62V+18V-18V+70V-70VPROTECTSENAC
25、 OFFSC NPNSC PNP+62V-62V-62VAGNDAGNDAGNDISC TRIGAGND+62V+18V-18V+70V-70VPROT1SEN1ACOFFSCN_4+62V_4-62V_4-62V_4AGND4AGND4AGND4ISCTRIG_1+62V_4+18V-18V+70V-70VPROT2SEN2ACOFFSCN_4SCP_4+62V_4-62V_4-62V_4AGND4AGND4AGND4ISCTRIG_2+62V_4+18V-18V+70V-70VPROT3SEN3ACOFFSCN_4SCP_4+62V_4-62V_4-62V_4AGND4AGND4AGND4
- 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:
- NAD-M25-pwr-sm 维修电路原理图 NAD M25 pwr sm 维修 电路 原理图