High Voltage Power Supply - Panasonic TC-26LX20 Technical Manual

High Voltage P ower Supply
A CCF tube needs high voltage. The starting voltage is generally over 1,000 volts and
th e operating voltage is generally be tween 200 and 500 volts rms.
Most CCFT DC to AC inverters are tuned switchers designed to produce a specific
voltage, frequency and output current when a designated tube is connected to the
output. The classic current-fed two-transistor inverter has a tuned resonating output,
tuned resonating input and inductive dc input which provides for good power transfer
and high operating efficiency.
Figure 33
The type of circuit depicted in Figure 6 inherently produces a pure sine-wave output, but
the voltage and current waveforms are both distorted when they are applied to a CCF
tube, which is a highly nonlinear device. The transition from the starting voltage to the
operating v oltage in this circuit is implem ented by a small internal series output
ca pacitor, which serves as the balla st, pro vidin g imped ance, and allowing prop er tube
current a fter the tube has be en ignited.
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