Table 3 Xtva Functions - Motorola Astro XTS Instruction Manual

Table 3 XTVA Functions

Condition Charger
No Radio: OFF
Radio Loaded:
Radio OFF: ON*
Radio ON: ON*
* — Provided the ignition switch is ON
Q19 driver and Q6 detector operate charger dc switch Q4.
Components R216, R166, R167, R330, and R208 hold Q6 in
conduction until a radio battery is connected by loading a radio. The
voltage at Q6 gate drops due to (console rev. "A") the contact of the
radio battery code resistor, or (console rev. "B" and higher) contact
across the universal contact ground (pin 8) and the XTVA's grounded
charge contact; Q6, Q19, and Q4 switch to opposite states. Diode D9,
supply hold, allows processor U5 to control XTVA power down.
The audio section dc switch, Q5, is operated by Q18. Q18 conducts
only when the radio is turned on by radio signal option B+ at
connector J6, pin 5.
Audio
VRS
Circuit
OFF ON
OFF OFF
ON OFF
RS232
OFF
OFF
ON
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