Service manual

SRP-150
Rev. 1.02
- 32 -
4-3 Special Circuit Descriptions
4-3-1 Power Circuit
This system is operated under 100Vac or 240Vac. The power circuit supplies the three differential DC voltage
sources.
Figure 4-3-1 Power Block Diagram
No1. Drawer Driving: +12VDC
+12VDC is supplied from SMPS. This Voltage is smoothed by capacitors.
This voltage is used as a Cash Drawer Solenoid Driving voltage.
No2. Voltage : +8.5V (Thermal Printer Head Voltage / Step Motor Voltage )
Change the input 12V to 8.5V by a regulation. (LM2575S-ADJ)
No3. Logic IC Driving Voltage: +5V
Change the input 8.5V to 5V by a regulation. U30(BA17805FP_E2).
No4. Logic IC Driving Voltage : +3.3V (CPU, Flesh, SRAM, Reset Voltage)
Change the input 5V to 3.3V by a regulation. U31(BA033).
No. VOLTAGE DESCRIPTION
1 VPP(+12VDC) Cash Drawer Solenoid Driving
2 VTH(+8.5VDC) Thermal Printer Head (TPH) Voltage / Step Motor Voltage
3 Vcc(5 VDC) Logic
4 Vdd(+3.3VDC) CPU, Flesh, SRAM, Reset Voltage, Sensor Voltage