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Chapter 2 Power System
2.1 Power Supply
Main Power
The PDT is operated by a rechargeable NiMH battery pack with two AA
size 1.2V 1500mAH capacity or two AA alkaline batteries for the main
power source.
Back up Power
An onboard 3V 190mAH Lithium battery (CR2032) is used as the
secondary power source to back up the data in RTC (real time clock chip)
and RAM memory to provide users a data-loss free environment.
Normally the PT600 gets power from main power source to back-up RTC
and RAM and puts the Lithium battery in standby state. When the main
power source is removed or below the level to back-up the RAM and
RTC properly, the power circuit of the PT600 automatically switches to
the Lithium battery for back up. It is recommended that the main battery
be always placed inside the unit with enough capacity for back-up
purpose in which case the Lithium battery can supply the power for up to
5 years
before consuming all its capacity up.
2.2 Power Low Indication
Main Battery
When the main power source reaches the
battery low condition, a warning message as
right will be shown on the LCD when PT600 is
powered on or a battery
low icon sign
will
emerge on the right sidebar of LCD.
! WARNING !
MAIN BATTERY
VOLTAGE LOW
