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1. Technical description
1.1. General description.
The SG108-BR is dedicated for uninterruptible power supply of 8 IP cameras (52V DC power supply) and
uninterruptible power supply of the DVR (12V DC power supply).
The main elements of this system include:
- 10 ports PoE switch
- buffer power supply unit 27,6V which can accommodate two 17Ah / 12V batteries
- a converter (DC/DC52230) increasing the voltage to 52V DC (supply of the PoE switch)
- a converter (DC/DC50SD) buck to 12V DC (DVR power supply)
In case of power decay, a battery back-up is activated immediately.
The approximate backup time is given assuming that all output ports are used (using typical devices and 17Ah
batteries). The electricity consumption for own needs and the energy efficiency of the power intake track were taken into
account. The exact description of how to perform the calculations can be found at:
"Approximate backup time - assumptions for
Automatic detection of any devices powered in the PoE/PoE+ standard is enabled at the 1 - 8 ports of the switch.
The Up Link ports is used for connection of another network device e.g. recorder. The LEDs at the front panel indicate the
operation status (description in the table. 8).
The switch is housed in a metal enclosure (color RAL 9003) which can accommodate a two 17Ah/12V batteries. The
enclosure features a micro switch tamper indicating door opening (front panel). The SG108-BR is fitted with two LEDs on the
front panel (red LED
– indicates 230V AC power supply of the PSU, green LED indicates the presence of DC voltage).
The PoE technology ensures a network connection and reduces installation costs by eliminating the need to supply a
separate power cable for each device. This method allows supplying other network devices, such as IP phone, wireless
access point or router.
1.2 Block diagram.
Fig. 1. Block diagram.
