High voltage hold down circuit

Claim 1

In a television receiver having a main source of operating potential, a horizontal deflection circuit of the type including a damper diode which limits the amplitude of flyback pulse excursions to substantially a single polarity, and protection means to sense the amount of current being drawn from said source by the circuits of the receiver and to disable said source when said current exceeds a predetermined value, wherein said deflection circuit includes a high voltage generating circuit having an input voltage which is representative of the flyback pulse, and wherein said high voltage generating circuit rectifies the peak-to-peak input voltage in developing said high voltage, apparatus for sensing such decrease in damper diode limiting action as might cause the developed high voltage to increase to a level at which X-radiations could be produced in response to the resulting increase in flyback pulse amplitude, comprising: a horizontal output tranformer including a secondary winding, a peak detector circuit coupled to said secondary winding for developing a direct voltage substantially only in the event that said damper diode current path is opEn circuited, and a semiconductor device having an input electrode coupled to a point of reference potential, an output electrode coupled to said source of operating potential, and a control electrode coupled to said peak detector circuit and responsive to the direct voltage developd by said detector circuit to increase the amount of current drawn from said potential source beyond said predetermined value when said damper diode current path open circuits and to thereby disable said source of operating potential and inactivate the circuits of said television receiver in response thereto.