Sony PMW-EX1 Service Manual page 17

8. Power supply system
RE-250/251 board
This board is comprised of the power supply circuit and
the POWER SUPPLY MICON (power supply u-processor:
IC1001 on the RE-251 board).
However, part of the low-voltage power supply is mounted
on the DPR-289 board.
(1) Input power supply (UNREG) system operations
When the UNREG power is input, the EVER power state
is established.
In this state, the ON/OFF state of the Power switch can be
recognized.
If the POWER SUPPLY MICON (power supply u-
processor: IC1001) recognizes that Power switch is ON,
the power is turned on for the system control system and
the POWER SUPPLY MICON (power supply u-processor:
IC1001) controls the power supply for each block accord-
ing to the system controller (DPR-289 board: IC1600).
The normal value for the input power supply (UNREG) is
in the range of about +10.5 V to +18 V.
. Battery/EXT-DC select
Input power comes in two systems: Battery and EXT-
DC. This switch monitors the input voltage for each
input and automatically switches the circuit settings with
priority given to EXT-DC.
. Input overvoltage protection
If the voltage is too high in the UNREG power supply,
the overvoltage protection circuit starts operating around
the set value of +17.9 V, and the camera shuts down.
When the input power supply voltage to this circuit
becomes less than +17.9 V, the power supply immedi-
ately switches on with automatic recovery.
. Input low-voltage protection
If the voltage is too low in the UNREG power supply,
the low-voltage protection circuit starts operating around
the set value of +10.5 V according to the control by the
POWER SUPPLY MICON (power supply u-processor:
IC1001), and the camera shuts down. When the input
power supply voltage becomes higher than +10.5 V, the
power supply immediately switches on with automatic
recovery according to the control by the POWER
SUPPLY MICON (power supply u-processor: IC1001).
. Overcurrent detection
The overcurrent detection circuit is comprised of IC308
on the RE-250 board. The setting value is approximately
4.3 (A). Even after clearing IC308 after overcurrent
detection, automatic recovery is not performed and the
power must be turned on again.
PMW-EX1
. Power supply reverse connection protection
If the input power has reverse voltage, Q301 on the RE-
250 board is immediately turned off and UNREG power
is stopped on the GND side, and the protection function
works.
(2) DC/DC converter function
The power supply output is divided into 25 systems, which
are separated into four blocks as seen below.
. CMOS/camera block system, 7 systems
(+4.6 V, +3.1 V, UNREG, etc.)
. Audio/video signal system, 7 systems
(+13.5 V, _4.6 V, +4.6 V, etc.)
. System controller system, 5 systems
(+4.6 V, +3.1 V, +2.5 V, etc.)
. Media recording/playback system, 6 systems
(+3.1 V, +2.5 V, +1.8 V, etc.)
The sequence control (powering up and powering down)
for the power supply system is controlled by the POW-
ER SUPPLY MICON (power supply u-processor:
IC1001) for the respective power supply blocks of each
block.
By turning off the power for each block according to the
operation mode (camera mode or media mode), the
optimal power consumption for each operation is
achieved.
. Short-circuit protection for each power supply system
The circuit settings monitor each output voltage or
current for each power supply system and operate the
protection circuits per block.
Even after the protection circuit is cleared, automatic
recovery is not performed and the power must be turned
on again.
Even after short-circuit is cleared, the protection circuit
does not recover automatically and the power must be
turned on again.
Battery information functions
. Battery authentication function
The authentication function checks whether the battery is
of the specified type. This helps prevent one cause of
major accidents when using batteries as a power supply.
If the attached batter is not the specified type of batter,
the camera immediately turns off.
. Battery Info function
In an intelligent (specified) battery, the battery can
monitor information, such as how many times the battery
has been recycled or the internal temperature for the
battery. This helps provide detailed information about
the battery, including whether the battery is damaged or
how long the life is, in order to provide optimal operations.
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