RF Output
5-8
Force 2 Service Manual
load impedances a one shot triggers by transformer primary voltages
below -100V. This one shot places a resistive load across the output and
reduces high frequency risk currents.
The FET output is rather low impedance, and the choice of DC supply
voltage as the power control parameter limits its voltage compliance.
Above 300 ohms load, the output resembles a constant voltage source.
Below 300 ohms load, the current limit circuitry enforces a constant
current characteristic. All eight output FETs must be the same type.
The bipolar control adds an op amp to the power supply feedback path.
This amplifies the difference between the RF output peak voltage and the
power supply set point voltage. The difference is summed with the
feedback supply voltage by injecting current into the feedback divider to
reduce the supply under high impedance load conditions. Current
injection enables only in the bipolar mode.
Summary of Contents for Force 2-2 PCH
Page 1: ...Service Manual Force 2 Electrosurgical Generator...
Page 10: ...Notes x Force 2 Service Manual...
Page 16: ...Notes 2 4 Force 2 Service Manual...
Page 32: ...Notes 4 10 Force 2 Service Manual...
Page 52: ...Typical Output Waveforms 6 12 Force 2 Service Manual Figure 6 5 Coag 300 Load...
