Interface Circuitry - Tait TM8100 mobiles Service Manual

Connector Power
Supply Options
Figure 3.11 Connector power supply options
Primary
Power
Source
3.7

Interface Circuitry

Introduction
90 Circuit Descriptions
Power from the radio's primary power source is fed to the auxiliary, internal
options, control head and microphone connectors. Whether power to these
connectors is unswitched, switched or not supplied is determined by
hardware links LK5 to LK8 on the top side of the main board, as shown in
Figure 3.11 and Table
Unswitched power means that power will always be supplied to the
connector while the primary power source is connected to the radio and is
alive. The supply to the connector is not affected by the state of the radio.
Switched power means that when the radio is off or in standby mode, the
power to the connector is switched off. The power will also be switched off
if the primary power source voltage is outside the radio's operating range.
The combined switched current drawn by the internal options connector,
the auxiliary connector and the control-head connector must not exceed
1A.
Note
The switched output is protected. Short-circuiting the switched
power on any connector will not damage the radio. In the event
of a short circuit, the current folds back to protect the switch
device and connectors.
LK8
(R786)
Power +13V8 BATT
Connector
Note
The links LK7 and LK8 have the alternative designations R787
and R786 respectively. The factory-default setting is with LK5
and LK7 inserted and LK6 and LK8 omitted.
For a block diagram of the interfaces circuitry, refer to
For more on the connector pinouts, refer to
3.4.
1
LK7
(R787)
8
LK5
+13V8
2
LK6
© Tait Electronics Limited November 2007
Internal
Options
Connector
Auxiliary
Connector
Control-
Microphone
Head
Connector
2
Connector
Figure 3.12.
"Connectors" on page
TM8100/TM8200 Service Manual
38.