Power Supply Circuit - Epson TM200 Service Manual

The cover open sensor is located next to the thermal printer mechanism, and it is
connected via Door Sensor board assembly to the main circuit board unit. Detector
signal INPUT_4 is input to the CPU.
Control Panel Control Circuit
This control panel is located on the mainboard. It has three LEDs (POWER, ERROR,
PAPER) and one button (FEED). The POWER LED drives when +5V is supplied by the
power circuit. The ERROR and PAPER LEDs are controlled by the CPU.
Drawer Kick Control Circuit
When signals KICK_OUT_X1 and KICK_OUT_X2 from CPU go active, it causes
transistor array and outputting the drawer drive signal. The OPEN_CLOSE signal,
which indicates whether or not the drawer is open, is input to the CPU, and this status
can be obtained from the host interface.

Power Supply Circuit

The table as below shows supply voltage values and their applications.
Power supply voltage values and applications
Voltage Value
1.8V
3.3V
+5V (VCC)
+24V
+24V Control Circuit
The +24V power supply is split between the printer power supply and +5V. Then
split into 3.3V and 1.8V.
+5V Control Circuit
A +5V regulator circuit switches the input +24V power supply and converts it to +5V.
The switching regulator IC switches the input +24V, and +5V voltage is output.
The RS-232 power supply is generated by a charge up circuit built into the RS-232
interface's onboard driver.
Main Applications
Power supply for the CPU core
Power supply for the CPU I/O pins
Logic circuit power supply
Interface board power supply
Detector power supply
Thermal head logic circuit power supply
Printer mechanism power supply
Paper feed motor
Thermal head
Autocutter
Drawer kick driver power supply
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TM200 Service Manual