Epson LQ 1050 Technical Manual - Page 55

REV.-A The power supply circuit is divided into the PEGX board, PEBFIL-11 board, and power supply transformer. This circuit converts the AC voltage from the step-down transformer into the DC voltage required to drive the printer mechanism and operate the control circuits. The AC voltage from outside the printer is input to the step-down transformer via the filter circuit. The AC voltage is converted to 26 VAC and 12 VAC by the transformer, and is input to the power supply circuit on the PEGX board. The 26 VAC is converted to approximately 36 VDC by the full-wave rectifier and smoothing circuit. The unregulated DC voltage and the regulated +24 VDC and + 5 VDC (total of 3 supplies) are supplied to the control circuit. Switching regulator IC NJ M2355 (1A) controls the chopper-type switching regulator circuits for +24 VDC and +5 VDC. The +36 VDC and +5 VDC are supplied to the Vx voltage circuit, converted to the Vx voltage, and supplied to the reset circuit. The 12 VAC is converted to unregulated 12 VDC by the positive half-wave rectifier and the smoothing circuit, and is supplied to the control circuit. Table 2-2. Power Supply Application Voltage Application +5V Logic circuit Plunger solenoid holding voltage Paper feed motor holding voltage Signal pull-up voltage +36V (vu) Plunger solenoid driving voltage Paper feed motor driving voltage Carriage motor driving voltage +24V I Printhead driving voltage (Vp) Option interface voltage + 12V - 12V Option interface voltage 2-11 ,,