The Power Supply Board - HP M2350A Service Manual

Understanding the Recorder Module
The Power Supply Board
The Recorder Module consists of the following subassemblies:
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power supply board
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digital board
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thermal array printhead
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paper drive motor
The Power Supply Board
The power supply pcb is parallel to the back of the module. Both power and data signals
enter the recorder through the power supply board. The board uses a dc-to-dc converter
synchronized to 78 kHz supplied from the Rack Interface to convert the 6OVdc input into
+5Vdc and + 15Vdc used by the digital board, motor drivers, and printhead. Signals to and
from the thermal recorder control board pass through infra-red optical isolators to eliminate
noise.
Circuit ground throughout the thermal recorder module connected to the power-ground circuit.
However, there is a separate reference ground in for the serial communications lines.
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