Generation of stepped voltages for color television and the like

Claim 2

Apparatus for producing stepped voltages comprising transformer means having secondary winding means connected in resonant-circuit combination with capacitance, said transformer means including inductance-changing means having primary winding means inductively coupled with said secondary winding means and capable of being switched between different states in which it causes said secondary winding means to exhibit different values of inductance, and control means, including electronic valving means and further electronic valving means, for switching said inductance-changing means between said different states, said control means including means for supplying electrical energy to the resonant-circuit combination through said valving means intermittently and synchronously with certain of the switchings between said different states and capacitor means for storing at least part of said energy externally of said resonant-circuit, and means for discharging the storage of said energy through said further valving means and said transformer means intermittently and synchronously with other of the switchings between said different states; said primary winding means including a first primary winding connected with said energy supplying means through said control means and a second primary winding connected in a discharging relation to said capacitor means through said control means.

Claim 3

A color display system comprising: a screen including phosphors which emit light of different colors when struck by electrons of different energies said screen forming a capacitive electrical load; an electron gun for emitting a beam of electrons toward said screen; field generating means for deflecting said beam of electrons in a scanning raster; means for applying a DC bias voltage to said screen to accelerate electrons emitted from said gun toward said screen; a transformer having a primary winding and a secondary winding, said secondary winding being adapted to be connected to said screen for applying a time-varying voltage thereto; a first switching circuit for connecting said primary winding across a voltage source, said first switching circuit including a first electronic switching means and a capacitor in series with each other and with said primary winding, said first switching means having a gate terminal; a second switching circuit including a second electronic switching means which is connected across said primary winding and said capacitor from a first junction between said first switching means and said primary winding to a second junction on the side of said capacitor and primary winding opposite said first switching means, said second electronic switching means having a gate terminal; and mEans for applying signals to the gate terminals of said first and second switching means for triggering said first and second switching means into conduction alternately, said transformer having leakage reactance which, upon triggering of either of said first and second switching means, causes said capacitive load to be charged to a respective voltage which then reversebiases the triggered switching means, whereby said screen is switched repetitively between at least two different voltage levels each of which persists until the next switching means is triggered and whereby said electrons are accelerated to at least two different energies for energizing said screen to produce multiple-color images.

Claim 4

A color display system comprising: a screen including phosphors which emit light of different colors when struck by electrons of different energies said screen forming a capacitive electrical load; an electron gun for emitting a beam of electrons toward said screen; field generating means for deflecting said beam of electrons in a scanning raster; means for applying a DC bias voltage to said screen to accelerate electrons emitted from said gun toward said screen; a transformer having a primary winding and a secondary winding, said secondary winding being adapted to be connected to said screen for applying a time-varying voltage thereto; a first switching circuit for connecting said primary winding across a voltage source, said first switching circuit including a first electronic switching means and a capacitor in series with each other and with said primary winding, said first switching means having a gate terminal; a second switching circuit including a second electronic switching means which is connected across said primary winding and said capacitor from a first junction between said first switching means and said primary winding to a second junction on the side of said capacitor and primary winding opposite said first switching means, said second electronic switching means having a gate terminal; and mEans for applying signals to the gate terminals of said first and second switching means for triggering said first and second switching means into conduction alternately, said transformer having leakage reactance which, upon triggering of either of said first and second switching means, causes said capacitive load to be charged to a respective voltage which then reversebiases the triggered switching means, whereby said screen is switched repetitively between at least two different voltage levels each of which persists until the next switching means is triggered and whereby said electrons are accelerated to at least two different energies for energizing said screen to produce multiple-color images.