Icom IC-A110EURO Service Manual Addendum

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Icom IC-A110EURO Service Manual Addendum Manual pdf 47 page image

3 - 53-4 POWER SUPPLY CIRCUITSVOLTAGE LINES (MAIN UNIT)LINEVCC8V+5VCPU5VT8R8DESCRIPTIONThe voltage from the external DC power con-nector which is controlled by the power switch([VOL] control).Common 8 V converted from the VCC line by the+8 V regulator circuit (IC29). The output voltageis applied to the +5 V regulator circuit (IC7), theripple filter (Q16), and etc.Common 5 V converted from the 8V line by the+5V regulator (IC7) and +5V current amplifier(Q22, Q23, D15) circuits. The output voltage isapplied to the electric volume IC (IC13), bufferamplifiers (Q68, Q69), and etc.Common 5 V converted from the VCC line by +8V regulator (Q82, D35) and +5 V regulator cir-cuits (IC26). The output 5 V voltage is applied tothe CPU (FRONT unit; IC1).8 V for transmitter circuits regulated by the +8 Vregulator circuit (IC29).8 V for receiver circuits regulated by the +8 Vregulator circuit (IC29).3-5 PORT ALLOCATIONS3-5-1 OUTPUT EXPANDER IC (FRONT UNIT: IC5)Pinnumber4, 56711121314PortnameLED1,LED2TRCR/TSMUTAFMUTRMUTTMUTDescriptionOutputs backlight control signals.Outputs control signal to the MOD/AFswtich (MAIN unit: IC48, pin 5) andetc.High: While transmitting.Outputs control signal to the TX/RXswitch (MAIN unit: Q58, pin 1) forVCO.Low: While transmitting.Outputs AF mute swtich (MAIN unit:IC30, Q86, Q75, Q74, D43) controlsignal.Low: While squelched.Outputs control signal to the muteswitch (MAIN unit; Q100, Q101, D66)for speaker amplifier, and etc.Low: While the speaker output ismuted.Outputs RMUTE switch (IC6) controlsignal.Low: While squelched.Outputs T8 regulator control signal.Low: When TX is muted.LED1LowHighLowHighLED2LowLowHighHighBacklight conditionLight OFFNo establishmentLight ON, Dimmer ONLight ON, Dimmer OFF