Tait TM9300 DMR Installation Manual page 31

Power Connector
25W
Table 4.1 Power connector (radio) - pins and signals
Pinout
30-50W radio
rear view
25W radio
1 2 3 4
rear view
Selecting the Power
Source
24V-to-12V
Converter
25W
Ignition Signal and
Standby Current
TM9300/TM9400 Installation Guide
© Tait Limited December 2015
The power connector is the interface to the vehicle battery and an optional
external remote speaker. Connecting a remote speaker is described in
"Connecting an External Speaker" on page
Pin Signal name
1 AGND
2 SPK–
3 SPK+
4 13V8 BATT
Notice This radio is designed to operate from a nominal 12V nega-
tive ground supply and may draw up to 15A of current. The radio will
tolerate a supply voltage range of 10.8V to 16.0V at the radio.
In passenger vehicles, the radio is always connected directly to the battery
using the power cable provided.
Notice Do not connect the radio to the centre tap of two 12V batter-
ies! This may result in damage to the radio due to earth loops, in partic-
ular when the negative lead is disconnected from the vehicle battery. It
may also result in overcharging or undercharging of the batteries, reduc-
ing their service life.
In trucks, where direct connection to the battery is often not possible, the
radio can be connected to a suitable terminal inside the fuse box that is
connected directly to the battery.
In vehicles with a supply voltage larger than 16.0V, such as many trucks, it
is essential to provide a 24V-to-12V converter with a minimum rating of
15A for radios 30-50W and 10A for the 25W radio. This will isolate the
radio from excessive battery voltage and provide the correct DC operating
conditions. Note that most 24V-to-12V converters already fitted are not
rated sufficiently.
When connecting the radio to the battery without using the ignition signal
as described on page 36, the standby current is approximately 50mA.
When using the ignition signal to turn off the radio, the standby current is
reduced to <3mA.
33.
Description
Earth return for radio body power
source
External speaker output.
Balanced load configuration
External speaker output.
Balanced load configuration
DC power input for radio body and
control head
Signal type
Ground
Analog
Analog
Power
Installing the Radio 31