Alinco DR-135, Service Manual

Page: 13 / 71

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11) Power Supply Circuit
When power supply is ON, there is a "L" signal being inputted to pin 39 (PSW) of CPU which enables
the CPU to work.
Then, "H" signal is outputted from the pin 41 (C5C) of CPU and drives ON the power supply switch
control Q8 and Q7 which turns the 5VS ON.
5VS turns ON the PLL IC116, main power supply switch Q127 and Q122, AF POWER IC117 and the
8 V of AVR (IC115).
During reception, pin 29 (R5) of CPU outputs "H" level, Q124 is ON, and the reception circuits supplied by 8 V.
While during transmission, pin 28 (T5) of CPU outputs "L" level which is reverse by Q11 so that the output
in Q128 will be "H" level, Q123 is ON, and the transmission circuit is supplied by 8 V.
Or, in the case when the condition of PLL is UNLOCK, "H" level is outputted from pin 14 of IC106,
UNLOCK switch Q129is ON, transmission switch Q128 is OFF which makes the transmission to stop.
1. ACC External Power Supply Terminal
When optional power supply cord DEC-37 etc. is connected to the external
power supply terminal JK101, with ACC power supply ON, switch Q101 will
turn ON, 5 V of AVR IC101 pin 2 (STB) becomes "L" which makes C5V to turn
ON. With this, it can turn the power supply of the radio ON.