Kenwood NXR-800H Service Manual

NXR-800H213-6. High temperature detector circuitThe high temperature detector circuit consists of a ther-mal switch IC (IC7) and a switching FET (Q2).This circuit lowers the transmitter power when the finalunit temperature is too high (83°C or higher).3-7. FAN action control circuitThe FAN action control circuit consists of a FAN and aAVR (IC12).3-8. Current detector circuitThe current detector circuit monitors the current of thePower Amplifier Module. It consists of a current detectionresistance (R4) and a current detection IC (IC1). It detectsthe normal and abnormal state of the Power Amplifier Mod-ule by monitoring the current of the Power Amplifier Mod-ule. If a failure occurs, it stops operation.CIRCUIT DESCRIPTION / 电路说明3-6. 高温检测器电路高温检测器电路由热控开关 IC(IC7) 和切换 FET(Q2) 组成。末级单元的温度过高时 (83℃或更高 )，该电路便会降低发射机功率。3-7. FAN 动作控制电路FAN 动作控制电路由 FAN 和 AVR(IC12) 组成。3-8. 电流检测器电路电流检测器电路监测功率放大器模块的电流。它由电流检测电阻 (R4) 和电流检测 IC(IC1) 组成。它通过检测功率放大器模块的电流来检测功率放大器模块的正常和异常状态。如果发生故障，它将停止操作。Fig. 12 High temperature detector circuit / 图 12 高温检测器电路Q2SWPoutVDDVGGPinIC10Power moduleIC7TempprotectionICFig. 13 FAN action control circuit / 图 13 FAN 动作控制电路Fig. 14 Current detector circuit / 图 14 电流检测器电路MIC12AVR FAN_CONTVBATTIC1Currentsense ICPA_CURRR4