Kenwood TS-60S Service Manual

Also see for TS-60S: Instruction manual Instruction manual Instruction manual

CIRCUIT DESCRIPTION3. Protection circuitWhen the reflected wave voltage (VSR) detected bythe filter unit rises, Q6 (2SC2714(Y)) in IC11 turns on t oreduce the voltage of the ALC time constant line. Thedrive is decreased and the power is reduced t o protectthe final transistor.4. Temperature protectionIf the final heat sink temperature rises, 0 8 in thefinal unit turns on and the fan starts running at lowspeed in both transmit and receive modes. If the finalheat sink temperature rises further, Q9 turns on, andthe fan rotates at medium speed in both transmit andreceive modes. If the temperature rises further still,the fan rotates at high speed in transmit mode, and at7medium speed in receive mode t o reduce the fannoise.If the temperature continues t o rise, the tempera-ture detection port of the microcomputer (IC1 in thedigital unit) is made high t o reduce the RF output forci-bly. If the fan fails or does not rotate because some-thing is stopping it, the RF output is forcibly reduced inthe same way.2. Reset circuitIC4 (M62003FP) monitors Vcc applied to the micro-computer. If the voltage falls below 2.15V, the IC out-puts a reset signal (low) to the microcomputer, and theCPU initializes all internal data (including memory chan-nel data). The reset signal is not output when thepower is turned on or off or 14V is turned on or off. It isoutput when the battery voltage level goes low and14V is turned on or off.C35 generates the signal width (td) required to resetthe microcomputer. (Fig. 12)Digital Control Circuit 4.35~The TS-GOS digital control circuit comprises a 16-bit 2,15Vmicrocomputer (M37702M4A-FP), a reset IC(M62003FP), an EEPROM (NM93C66LEM8 orAT93C66-10S12.7), a latch (TC74HC573AFL and a de-coder (TC74HC238AF). The latch and decoder are 1 ' 1used to expand the output ports. The decoder outputsan enable signal pulse.- 1. Power buttonWith this transceive, the power is turned on and off RESET RESETby the microcomputer. When the power bunon ispressed, the microcomputer detects it and energizes, Fig. 12 Reset circuitthe power relay t o supply 14V t o the transceiver.When the power button is pressed to turn the trans-ceiver off, the microcomputer checks it a little longerthan when turning the power on, and deenergizes thepower relay.