Epson 890N - FX B/W Dot-matrix Printer Service Manual page 49

EPSON FX-890/2190
Table 2-2. Major Elements on MAIN Board (continued)
Elements Location
Driver element: DTC124X
Control:
Energy save (ESA
VE) circuit
90 V constant voltage circuit:(2 circuits each of which is
constituted with 9 pins)
Type:
Driver element:FET 2SK3155 (Hitachi)
Simple ecodrive
Input eco voltage:88.7 V ~ 95.8 V
circuit
Output power voltage:+42 V
Overvoltage detecting circuit (OVP): Detects 120 V or
Operating Principles
Function
Controlled by output port (P_CTRL) of ASIC
Register setting
0: 42 V power voltage rising (Power ON)
{At reset}
1: 42 V power voltage lowering
Constant-voltage dropper circuit (for head
power regression)
±
5% (Controlled to a constant
voltage by Power Supply Unit.)
above as a overvoltage.
Outputs Off signal to the Power Supply Unit.
Figure 2-5. C524 MAIN Block Diagram
Overview
Revision B
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