9600 Service Manual - gmecorp-usa.com

kV Generation 3
The return path for the transformers is through relay K2 on the Generator Driver PCB.
Relay K2 is held energized by the 24V Interlock circuit. The purpose of relay K2 is to
prevent kV by opening the ground path for the Generator driver transformers T1 and T3
in the event that the 24V Interlock is lost.
Assuming relay K2 is energized, the Darlington driver transformer T3 will drive half of the
Darlington transistor Q2 (B1, C1, E1) and half of the Darlington transistor Q1 (B2, C2E1,
E2) during HVDRVA time. This causes current to flow from ground through L1, C1
(Located in the Generator Controller Assembly), the High Voltage Transformer primary
to B+ (VDC). When HVDRVA time ends and HVDRVB time begins, Darlington Driver
transformer T1 will drive the other half of the Darlington transistor Q2 (B2, C2E1, E2)
and the other half of the Darlington transistor Q1 (B1, C1, E1). This causes current to
flow in the opposite direction through C1, L1 and the High Voltage Transformer primary
to B+ (VDC).
In effect, the B+ (VDC) is chopped and then made into a sinusoidal signal by tuning
circuit C1 and L1 so the energy is effectively transferred to the Tank. The amount of kV
is determined by the on time of the Darlington Transistors. To increase kV the duty cycle
of HVDRVA and HVDRVB is increased. To decrease kV the duty cycle of HVDRVA and
HVDRVB is decreased.
CONTACT
RELAY K2
FLYBACK (L2)
TRANSFORMER
F1
L1
PRECHARGE
RELAY K1
C4
C1
Figure 1 - Generator Controller Assembly
C2
C3
DARLINGTON
PAIR