744T User Guide and Technical Information

The voltage level of the source powering the unit is shows on the LCD (). When the 744T senses a low voltage condition from an external DC source the power LED and battery voltage display flashes, to alert the user. When the external DC reaches 9 volts, the 744T will automatically switch over to its removable battery. If no battery is installed the unit will shut down.

The included AC-to-DC power supply can run the unit and charge removable batteries simultane- ously.

Charging

The 744T has a battery charger for the Li-on battery. The charger is active when 10–18 VDC is applied to pins 2 (–) and 3 (+) of the Hirose connector. When power is applied, the charging circuit evaluates the battery condition and supplies charging current, if necessary. When charging, the amber charge LED will flash. Once the battery is fully charged, the charger will enter a trickle mode to maintain the battery. The charge LED flashes to indicate the status of the charging circuit. The chart below describes the different flashes and their meanings:

Charge LED Activity

Description of Activity

 

 

 

 

Off

Charger disabled

 

 

 

 

On

Completed charge / battery fully charged

 

 

 

 

1 blink

Charger enabled / battery is charging

 

 

 

 

2 blinks

No Li-ion battery attached

 

 

 

 

3 blinks

High/low internal temperature state

 

 

 

 

4 blinks

Battery level error code (>15 min. in slow mode)

 

 

 

 

5 blinks

8 hour time limit error code

 

 

 

 

 

 

 

If the charge LED shows anything but a successful charge, the Li-on battery may require replacement.

Time Code Master Clock Battery

The 744T has an internal NiMH LR6 (AA) cell providing power to the time code generator circuitry and time-of-day clock. This battery is charged simultaneously with the Li-on battery. With a fully charged battery, accurate time code will be held for to eight hours after power down. Because of this battery the 744T can be powered down without worry of time code jumps or inaccuracy. When the NiMH battery is near exhaustion, the time code generator will shut off and the time-of-day clock keep running for up to one month.

744T will maintain accurate time code for 8 hours after power-down as long as the NiMH battery is charged.

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firmware v. 1.04 Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.