Service manual

Principles of Operation

This section describes the operation of the printer’s components, including the

power supply circuit, the reset circuit, the carriage mechanism, the paper feed

mechanism, and the printhead.

Power Supply Circuit

This section describes how the power supply circuit operates.

Power supply circuit block

diagram

120 VAC is applied through the filter circuit to the step down transformer, which

generates 26 VAC. The 26 VAC is input to the power supply circuit on the main

board.

The 26 VAC is converted into approximately 36 VDC via the full wave rectifier

and smoothing circuit. The 36 VDC is input to the regulator circuits, which

supply +24 and +5 VDC to the control circuit. The +24 and +5 VDC are also

supplied to the Vx voltage circuit. The Vx voltage circuit is applied to the control

circuit.

LQ-2OO/AP3000 2-9