Oki Microline 390 Maintenance Manual - page 38
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3.1 0 Power supply
The power supply consists of a power transformer, filter board, and DC power supply board.
The input AC voltage is transformed into 8.6 VAC, 46 VAC, and 10 VAC by the power transformer.
These AC voltages are rectified to + 8 VDC, + 5 VDC, and + 40 VDC levels by the DC power supply
board and supplied to the control board.
(1) Filter board
The filter board consists of the power switch, AC fuse and AC noise filter.
(2) Power transformer
If the internal temperature of the power transformer rises abnormally the built-in thermal fuse
will open to prevent any damage to other electrical components.
(3) Power supply board
Rectifies the AC voltage input to + 8 VDC, + 5 VDC and + 40 VDC and supplies it to the control
board.
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