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Switch ON circuit
MAMMOMAT Balance
SPB7-115.840.01 Page 11 of 62
Siemens AG
Troubleshooting Guide
Rev.02 10.04
Medical Solutions
Switch on circuit and sequence
Unit is switched ON by means of main contactor TLR1 and solid state relay RYS1.
Drive and timing circuit is on board of PCB 03-186, powered by TF129.
Switch On sequence
Main contactor TLR1 switches ON at first and dumping resistor R1 smooths inrush current of TF155,
TF165 and capacitors C1,C2,C3,C4.
After few seconds RYS1, with zero cross drive, shorts R1 and full power is available for H.V.
generator and other high power services.
Display and Keyboard initialization
Keyboard (PCB 92-083+03-181) has its own dedicated CPU.
At power ON, empty frame is drawn by keyboard CPU on the display.
When main CPU of PCB 01-170 starts, display frame is filled with icons.
Grid position initialization
At power ON grid is moved to search home position and noise from the table is normal.
Grid home position is at left side from patient position.
Emergency shutdown
Emergency push buttons located on both sides of MAMMOMAT Balance.
Operating Emergency push button will switch OFF immediately main contactor TLR1 and the whole
unit is switched OFF.
ON/OFF pushbutton and control lamp
Connected to CN16 of PCB 03-186 has control lamp inside.
Control lamp is bright when unit is OFF, after switch OFF, lamp blinks for a short time during which
further switch ON is disabled to allow high power circuit to reset.