GE AMX-II

GENERAL ELECTRIC MEDICAL SYSTEMS
AMX-I1 X-RAY UNIT
6-978
42 500 Hz Inverter Driver Output Couplers
Schematic reference sheet 5, Chapter 7.
Refer to Illustration 6-6.
SM A 0654E
2CR3
TIME DELAY FOR Q7
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Per
广 一 一 二 一 一 一 q R8
| | —
I | LI |
l
RIS bs | | |
3TI
SEC. = a4 | | FF sco) ce
(RY! Tu
-=
RS
CR2 R3
DI DI
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ILLUSTRATION 6-6
The inverter driver output transformer 3T1 secondary voltages are practically the same as one half the
primary voltages shown in W-23A or B. Capacitor C-6 charges to peak voltage through CR2 and R3. This
voltage appears as an SCR gate trigger spike when 07 turns on as shown in W-24,
A peak voltage as high as 100V is needed for gate triggering of 2CR3. Since 04 can handle only about
200 mA which produces only about 2V, 07 is used to obtain the greater power handling capability.
The base to emitter bias for Q7 is developed across R5 and R13 which also is the charge path for C12.
As described in Sec. 41, the SUS turns on when the voltage across it reacnes 7 to 9 volts. When Q7 con-
ducts the voltage developed across R8 triggers the gate of 2CR3.
6-9