TM9300/TM9400 Installation Guide
Power Sense and Connector Power Supply Options
23
© Tait Limited
December 2015
appropriately. The concealed microphone is typically fitted when the
emergency power-sense option is selected.
Operation in
Emergency Mode
If the radio is off when the emergency mode is activated, the radio is
powered up but the display on the control head is not switched on. If the
radio is on when the mode is activated, the display is frozen. In the latter
case, if the ON/OFF key is pressed, the display is switched off but the radio
remains in the emergency mode. While in this mode the radio cycles
between transmit and receive. To exit the emergency mode, the
ON
/
OFF
key
needs to be pressed again.
3.2
Connector Power Supply Options
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 FLK1N to FLK4N on the top side of the main board, as
shown in
and
Notice
The hardware links are SMT components. Do not replace
SMT components unless you are trained and equipped to do so.
Attempting to replace SMT components without the necessary training,
tools, and equipment can cause permanent damage to the radio.
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
2A.
The switched output is protected. Short-circuiting the switched power
on any connector will not damage the radio. In the event of a short cir-
cuit, the current folds back to protect the switch device and connectors.