User's Manual

Radio Activity S.r.l. 23 / 44
Internal power supply is not isolated. KAIROS must be supplied by an isolated power supply (from mains)
with a minimum isolation equal to the one of an IEC 61558-2-6 compliant safety transformer or equivalent.
The power supply input has the following characteristics:
Input Voltage
10.8
–
15.6 Vdc, neg. ground,
Nominal 13.2V
Max ripple
30 mVpp
Polarity reversal protection
up to
-
70 V
Power supply protections
Electronic protection with automatic restore for
overvoltage
and
undervoltage events
Short
-
circuit protection
Electronic protection with automatic
restore
Power supply connector
2 pole model Phoenix Contact
Power consumption @160MHz
13.2Vdc – typical values for both DMR
timeslot used
Power off : 1mA
GPS Receiver (without external antenna) : 30mA
LINUX & LAN (no TRX active): 150mA
LINUX & LAN
+ RX main on : 260mA
LINUX & LAN + RX main + RX Diversity on : 310mA
LINUX & LAN + RX main + RX Diversity + TX @1W : 1A
LINUX & LAN + RX main + RX Diversity + TX @5W : 1.8A
LINUX & LAN + RX main + RX Diversity + TX @10W : 2.5A
LINUX & LAN + RX
main + RX Diversity + TX @25W : 4.0A
The DMR TIER 2 standard doesn’t require a continuous transmission from the repeater. Thus it’s easy to
calculate the battery’s autonomy as the following example:
Considering a simple KAIROS repeater operating at 10W for the 25% of time, the mean power requirement
is: I_mean=2,5*25% + 0,310*70% = 625 + 230 = 855mA
In case of a main power supply failure, a small 65Ah battery pack gives more than 3 days of full operation.
3.3.5 I/O ports
KAIROS provides some I/O ports fitted into the 25 pin D-SUB connector and the 6 pins connector placed in
the back. Some of these I/O are specialized (e.g.: PTT_out or ALRM_out) but can be re-defined for special
applications.
I/O contacts are not isolated from ground, they are referred to ground and pre-polarized by +3.3V. Due to
this configuration, for safety reason, they can be connected to very low voltage external circuits only.
Here following it is descripted the standard applications of these auxiliary pins.