Siemens MULTIMOBIL 10 User manual

MULTIMOBIL 10

Function Description

SP

© Siemens AG 2003

The reproduction, transmission or
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is not permitted without express
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model _or_ design,_are_ reserved.

English
Print No.: SPR8-X01.850.10.02.02 Doc. Gen. Date: 10.05

Replaces: SPR8-X01.850.10.01.02

Multimobil 10

Service manual

Circuit Description

Med

Circuit Description

Version :4.0

The reproduction, transmission or use

of this document or its contents is not
permitted without express written
authority. Offenders will be liable for
damages.

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Service manual

Circuit Description

INDEX

1 MASTER CARD D915............................................................................................................................. 4

1.1 GENERAL DESCRIPTION: ................................................................................................................. 4

1.2 FUNCTION DESCRIPTION:................................................................................................................ 4

1.2.1 POWER SUPPLY: .......................................................................................................................... 4

1.2.2 RESET GENERATION: ................................................................................................................. 5

1.2.3 CRYSTAL OPERATION:............................................................................................................... 5

1.2.4 MICROCONTROLLER: ................................................................................................................ 5

1.2.5 OCTAL LATCH: ............................................................................................................................. 5

1.2.6 GAL: ................................................................................................................................................. 5

1.2.7 EPROM:........................................................................................................................................... 6

1.2.8 NVRAM:........................................................................................................................................... 6

1.2.9 KEYBOARD:................................................................................................................................... 6

1.2.10 DISPLAY(RADIOGRAPHY) :.................................................................................................. 6

1.2.11 SERIAL COMMUNICATION : ................................................................................................ 6

1.2.12 kV SOLL AND mA SOLL:......................................................................................................... 6

1.2.13 kV FEEDBACK :........................................................................................................................ 7

1.2.14 IH FEEDBACK:......................................................................................................................... 7

1.2.15 mA FEEDBACK: ....................................................................................................................... 7

1.2.16 kV REGULATION: .................................................................................................................... 7

1.2.17 FILAMENT REGULATION: .................................................................................................... 8

1.2.18 mAS INTEGRATION :............................................................................................................... 8

1.2.19 CONTROL OF THE FIRING FREQUENCIES REG and CAL:........................................ 8

1.2.20 GENERATION OF ACTUAL FIRING SIGNALS : ............................................................... 8

1.2.21 SHORT CIRCUIT FEEDBACKS (SCM,SCH) : .................................................................... 9

1.2.22 KV, MA MAX FEEDBACK (KVM,JIM ) ..................................................................................... 9

1.2.23 GENERATION OF ROTATING ANODE DRIVING AND CONTROL SIGNALS: .................... 10

1.2.24 ROTATING ANODE CURRENT FEEDBACKS : ...................................................................... 10

1.2.25 Line voltage monitoring ............................................................................................................. 10

1.2.26 Capacitor Bank Voltage Monitoring.......................................................................................... 10

2 MAIN INVERTER PCB D960 .............................................................................................................. 12

2.1 GENERAL DESCRIPTION: ............................................................................................................... 12

2.2 FUNCTION DESCRIPTION:.............................................................................................................. 12

2.2.1 Main Inverter: ................................................................................................................................. 13

3 FILAMENT INVERTER AND ROTATION CARD D801 ................................................................ 14

3.1 GENERAL DESCRIPTION: ............................................................................................................... 14

3.2 FUNCTION DESCRIPTION:.............................................................................................................. 14

3.3 ON -- OFF CIRCUIT: .......................................................................................................................... 14

3.4 DC -- DC CONVERTER...................................................................................................................... 15

3.5 FILAMENT INVERTER CIRCUIT: ................................................................................................... 15

3.5.1 Short circuit Detection and Protection : ........................................................................................ 16

3.5.2 Filament current (Ih) Feedback:..................................................................................................... 16

3.6 ROTATING ANODE CIRCUIT:......................................................................................................... 16

3.6.1 Rotating Anode Current Feedback: ................................................................................................17

3.6.2 CONTROL SIGNALS FOR THE RELAYS: ..................................................................................... 17

3.6.3 VOLTAGE MONITORING SIGNAL:.............................................................................................. 17

4 CHARGER PCB D950A (125 MAS)...................................................................................................18

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Service manual

4.1 GENERAL DESCRIPTION: ............................................................................................................... 18

4.2 FUNCTION DESCRIPTION:.............................................................................................................. 18

4.2.1 Power circuit:.................................................................................................................................. 18

4.2.2 CONTROL CIRCUIT ...................................................................................................................... 19

4.2.3 FEEDBACK CIRCUIT:................................................................................................................... 19

5 KEYBOARD PCB D936 ........................................................................................................................ 21

5.1 GENERAL DESCRIPTION ................................................................................................................ 21

5.2 FUNCTION DESCRIPTION............................................................................................................... 21

5.2.1 Keypad............................................................................................................................................. 21

5.2.2 Interface with Master Card ............................................................................................................. 21

6 DISPLAY CARD D932 .......................................................................................................................... 22

6.1 GENERAL DESCRIPTION ................................................................................................................ 22

6.2 FUNCTION DESCRIPTION............................................................................................................... 22

7 KV-MA FEEDBACK PCB D800 ......................................................................................................... 23

7.1 GENERAL DESCRIPTION ................................................................................................................ 23

7.2 FUNCTION DESCRIPTION............................................................................................................... 23

7.2.1 KV Feedback at R+, S, R- ............................................................................................................... 23

7.2.2 mA Feedback at P and N............................................................................................................... 23

Circuit Description

8 TERMINAL PCB D900A..................................................................................................................... 24

8.1 GENERAL DESCRIPTION ................................................................................................................ 24

8.2 FUNCTION DESCRIPTION............................................................................................................... 24

8.2.1 U , V ................................................................................................................................................ 24

8.2.2 11, 12............................................................................................................................................... 24

8.2.3 0 , I, II.............................................................................................................................................. 24

9 SWITCH MODE POWER SUPPLY D980 .......................................................................................... 25

9.1 GENERAL DESCRIPTION : .............................................................................................................. 25

9.2 FUNCTION DESCRIPTION :............................................................................................................. 25

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Service manual

Circuit Description

1 Master Card D915

1.1 GENERAL DESCRIPTION:

The Master Card D915 forms the main closed loop control system in the entire
X ray generator MULTIMOBIL 10.

1.2 FUNCTION DESCRIPTION:

The functions performed by D915 are as follows:

1.The microcontroller 80552 ( J31) on D915 executes the program which makes
the Xray generator work. J31 also genarates and receives proper signals for

most the activities of MULTIMOBIL 10.

2.The EPROM stores the entire bios software.

3.The Nonvolatile RAM stores all the temporary variables while execution of the
main program. Even at power OFF,it stores the last display-data.

4.The peripheral Ics along with J31 are used for generation of the driving signals

for

1. Main Inverter

2. Filament Inverter

3. Rotating Anode.
Additionally the peripheral ICs receive the feedback signals from the output
processes and feed it back to J31 for taking proper corrective action.

5. The faults such as accidental short circuit, mismatching of the actual value and
the reference value of KV,mA,or ms, improper operation of any

process are reported to the Master card for indicating error to the operator and
for taking necessary action ,if feasible.

6. The functions performed by D915 are as follows:

a) Accepting the key pressed by the operator through D936

b) Display the proper Radiography through D932

c) Genarating the reference values of KV (KVS) and mA (JRS) and

converting them to the driving pulses of the Main and the Filament
Inverter.

d) Accepting actual values of the set parameters and regulating the required

parameters.

1.2.1 POWER SUPPLY:

The +15,0V,-15V and +5V,0V voltages are obtained from the SMPS through the
connector X15.
The +Vp supply of 15V is obtained through X10 from the Filament Inverter and
Rotation card D801.
The reference voltage for the Microcontroller (J31) is 5V and it is generated by
R119 , C85, and J30.

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Circuit Description

1.2.2 RESET GENERATION:

The RST signal is generated by IC J40 (MAX 700 :power supply monitor with reset)
at power ON. The switch SW2 also allows for manual reset of the system.

On actuating SW2 ON, reset is generated by J40 which is applied to RST pin of
J31.

1.2.3 CRYSTAL OPERATION:

The 12 Mhz Quartz crystal forms a Pierce Oscillator along with the two capacitors
C93 and C95.The output of the oscillator is a 12Mhz sinusoidal wave which is
applied to XTAL1 and XTAL2 inputs of J31 for providing timings for internal
operations of the microcontroller.

1.2.4 MICROCONTROLLER:

The microcontroller J31 outputs demultiplexed lower order address bus and the
data bus on port ‘ P0’ and higher order address bus on port ‘P2’.

The control signal

RD , WR along with A8-A15 are provided to J28 (GAL) to

generate the chip select signals for accessing various peripherals.
The status signal

PSEN

is used for reading external program stored in EPROM

J32.

EA ‘LOW’ allows accessing the external program memory.

The
Different signals for controlling various operations of the entire system are provided
by the Microcontroller on its ports P1,P3-P5.
The analog inputs AN0-AN6 are used for monitoring analog signals.
The pins TXD and RXD are used for serial communication between the processor
and the external device such as a Computer or any pocket terminal (for servicing).
The Service switch ST provided at pin P4.5 is used for operating the Unit in the
service mode.

1.2.5 OCTAL LATCH:

The multiplexed address and the data bus is separated by the octal latch J27.
At the active ALE signal ,the lower order address (A0-A7) is latched.

1.2.6 GAL:

Since Memory mapping technique is used,the chip select signals for various
peripheral devices are generated by the Gated Array Logic IC J28.The inputs are

the address lines (A8 - A15) ,and the control signals

CS1 to CS8 . These output chip select lines are generated on the basis of the

are

RD and WR . The output lines

logic implemented in the program stored in the GAL.

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Circuit Description

1.2.7 EPROM:

The entire program is stored in a single EPROM J32.

1.2.8 NVRAM:

The Two Kbyte NVRAM stores the variables the operation of the unit.
A0 - A10 and D0 -D7 are the address and the data lines provided to the RAM.The
first 2 Kbytes of entire memory space 0000H to 07FFH is used as RAM.

1.2.9 KEYBOARD:

The keys are accepted through X12 from D936.
The keys ( KV+ , KV -, mAS+, mAS-,DL_SERV ) are accepted on the data bus
through J38 and J37at the address 9000H.
The ON, OFF signals are routed via X12, D915, X10 to D801.

1.2.10 DISPLAY(RADIOGRAPHY) :

The data bus, the control signal WR and the chip select signal CS2 are provided to
the Display Driver J24 on D932 through X1.Writing the control word and the string
of 8 byte data at the addresses 8000H and 8800H respectively displays the KV and
mAS values and lights up function related LEDs on D915.

1.2.11 SERIAL COMMUNICATION :

TXD , RXD are provided to the serial communication port of D915.Various activities
of the unit can be controlled by an external device such as a PC or a pocket
terminal.The serial port is meant for testing and service purposes.

1.2.12 kV SOLL AND mA SOLL:

The KV soll and mA soll values are generated by Dual Digital to Analog Converter
J17 and the Opamp J13 acting as I - V converter.
The microcontroiler J31 outputs the digital values of KV soll and mA soll on the

data bus at address A000H (

CS3) and A100H ( CS4 ) respectively.The reference

current for DAC is adjusted by means of presets P6 and P7.
The KV soll and mA soll are fed back to the AN3 and AN4 pins of J31 for ensuring
their proper values.These soll values are also used for regulation of KV and mA.
The KV soll ratio is 1 V = 30 KV and
The mA soll ratio is 1 V = 50 mA

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Service manual

Circuit Description

1.2.13 kV FEEDBACK :

The actual KVp across the tube is stepped down and fed back in the form of KV/2+
and KV/2- to the Master card D915 at pins 1and 2 as PKV and NKV respectively
with respect to the common terminal at pin 3.
PKV and NKV are passed through the voltage follower J5 and then fed to the
Differenial Amplifier formed by J5 to produce Kvist,which is used for KV regulation

(KVist ratio is 1V= 20 KV)
KV ist is fed back to AN7of J31 for monitoring purpose.

1.2.14 IH FEEDBACK:

The Filament current (Ih) feedback is taken from the Filament inverter and rotation
PCB through X11.1.J7 provides a gain of 5 to Ih.
The AC Filament current Iheiz is converted into DC value Ih by RMS - DC converter
J6.J9 provides an approprate gain to Ih (that can be adjusted by preset P5)
so that the ratio 1V = 2A holds true. Ih is fed back to J31 at AN2 for monitoring
purpose,the same is used for Ih regulation.

1.2.15 mA FEEDBACK:

The tube current (JR) is fed back in the form of voltages P+ and N- at pins 5 and 6
of X8 on D915. P+ and N- are applied to the Differential Amplifer formed by J4.
The output JR represents the actual tube current mAist which is fed back to J31 at
AN1 through J9 for monitoring purpose.JR is also used for tube current regulation.

1.2.16 kV REGULATION:

The KV soll and KV ist values are fed to the P-I controller formed by IC J10.
The difference between the KVist and KV soll value is amplified to produce an
appropriate error output , so as to compensate the error. The zener V12 limits the
maximum ouput voltage of the error amplifier to 10V.
The error amplifier output is fed to PLL IC J3 which is used as voltage to frequency
converter.
The J10 output voltage produces an equivalent frequency REG at J3 output.
For 10V, REG(the maximum firing frequency of the Main Inverter) is 15khz.
J3 is enabled by an active low INH2 signal provided by the microcontroller J31 at
P4.1 through J23.During HT, J3 is enabled through INH2 and J3 results in a firing
frequency of Main Inverter IGBTs, to result in actual KV in line with the required
value.

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