UPS25 8
RTD Embedded Technologies, Inc
Power supply unit
The UPS25 uninterruptible power supply unit is designed to provide a complete
backup system for your embedded computer and its peripherals. Battery
charging power is generated using a wide input voltage range (8 to 40V DC) step
down converter with a maximum charging output power of 25W. Battery charging
power is converted from this output using a second step-up DC/DC converter.
This scheme will enable charging of the batteries at +12V, while operating at an
input voltage of 10V. The UPS25 input is protected against reverse voltage up to
40V, and is over voltage protected using a 5 Watt 40 V zener diode.
Charger unit
While the main system power is present the onboard battery charger may charge
the external battery pack. However charging may be disabled by software by
writing to the appropriate charger control bit. Charging will not take place if any of
the following conditions are met: 1) main power is below 10V, 2) battery
temperature is out of limits, 3) battery is already charged, 4) battery error exists.
Host interface and control
The UPS25 can be controlled and monitored from software. A host interrupt may
be generated to indicate that the main power supply is below 10V and that the
system is powered from the battery pack. This interrupt can be used to start
required actions. The state of the UPS25 can be polled using status bits
indicating battery voltage level, charger state and battery temperature state.
Mechanical description
The UPS25 is designed on a PC/104 form factor. An easy mechanical interface
to both PC/104 and EUROCARD systems can be achieved. Stack your UPS25
directly on a PC/104 compatible power supply using the onboard mounting holes
and standoffs.
Connector description
All power connections are made using "cable plug" type terminal blocks. This
enables removing connections from the board without opening the cables from
the terminal blocks. Power must be removed before connecting or disconnecting
batteries. Hot swapping the battery pack may damage the UPS25.
