[Penthode]

This evening I have spent time consolidating the plan. The CT100 convergence transformer replacement I plan to fit in place within the box which contained the old transformer. It's purpose is to couple and step up the vertical convergence parabola waveform to feed the 15GP22 CRT electrostatic convergence plates. The convergence plates run at 3000volts dc with the parabola waveform to converge the beams at the top and bottom of the screen. The amplitude of the parabola must be about 500 volts p-p. The circuit I have designed I hope ill fulfil the vertical convergence in a more cost effective way without having to resort to using a specially constructed transformer.

The previous drawings were mainly for concept and included a few errors. The latest iteration I have attached here has the previous error fixed. This has only been tested on the bench and not yet connected to the CT100.

The 800 volts dc to provide a convergence waveform of sufficient voltage amplitude is incorporated into this drawing. Everything is self contained and it will not require any modification to the CT100. All the connections on the box go to the original connection except for one: an extra lead identified as "To Main Rectifier Junction" is to the connection where the two main rectifiers are connected. This connection facilitate the boosting to 800 volts to operate the IGBT, This will require a wire to be run from this convergence circuit to the main rectifiers.