Mitsubishi Electric APRICOT FT4200, Owner'S Handbook Manual

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P o w e r s y s t e m
14/6
(logic high) in the Standby and Power On modes. It is negated (logic low) in
the Backup and Power Off modes.
PSU state diagram
Power Off
Backup
Power On
Standby
Dead
(AC Good=False
AND Low Battery)
OR Fault
Low Battery OR
Shutdown=True
OR Fault
AC Good=True &
!15A Latch
(AC Good=False
OR Fault
AC Good =False
OR
AC input>15A
AC Good=True &
15A Latch &
Power Up
Shutdown=True
Power Up =True
AC Good =True
AC Good=False
AND
Deep Discharge
Figure 14-3 PSU State Diagram
The "Deep discharge" transition on the state diagram occurs when the PSU
detects a very low battery voltage while it is providing a Standby 5V supply
in Power Off mode. This can occur due to excessive battery drain or the
batteries being disconnected by the circuit breaker. In the case of battery
exhaustion in Backup mode, the PSU will remain in the Power Off state for
at least 0.5 second before entering the Dead state. If the circuit breaker
disconnects the batteries, the transition from Backup to Dead may be
instantaneous.
The "Fault" entries in the table below correspond to the equivalent
transitions on the state diagram. Other PSU failures may also cause the
"Fault" transition.
PSU mode truth table
State AC Good DC Good DC7
Dead Don’t care Don’t care Off
Power Off False False On
Standby True False On*
Power On True True On*
Backup False True On*
On* , Output is on in all except current limiting conditions on this output.