Trimble S - PSM board; Location; Function description

Chapter 3
Theory of Operation
Trimble S, VX, SPS & RTS Service Manual3 - 46 P/N 57150002, Revision 5.0
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PSM board
The PSM, Power Supply Management board is the power manager for the instrument.
Location
The board is located in the middle of the instrument above the base unit with angle and servo unit.
Fig. 3-45 PSM board location
Function description
The PSM, Power Supply Management board is responsible for:
1. Switching the instrument on and off.
2. Automatically selecting a good power source, internal battery or external power (external
power has always priority).
3. Reporting status of the power sources.
4. Generating the internal voltage to supply all other units with power.
5. Protecting the batteries against damages by deep discharge.
6. Controlling the temperature & pressure sensor
PSM board