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Old 01-23-2010, 11:13 PM
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Quote:
Originally Posted by jeyurkon View Post
In other words for the horizontal they take advantage of di/dt=v/L. But the slow di/dt required for the vertical would require a huge value of inductance, so it's easier to treat it as more of a linear circuit?
>>>>Correct

The damper must live a hard life handling the dump.
>>>>The horizontal output tube or transistor must do a controlled turnoff of the current. The damper does it "naturally".


John
I never worked on tube deflection design, so I don't know all the details, but for solid-state horiz circuits, the turn-off speed of the output transistor and the damper diode are critical to keep dissipation down and to avoid killing the transistor due to exceeding the "safe area" (simultaneous current/voltage limits). Generally, the horizontal drive waveform includes a negative pulse at turn-off (not simply going to zero), to pull stored charge out of the HOT base and shut it down as quickly as possible.
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