Constant-current vertical amplifier
AssigneeGTE Sylvania Incorporated
InventorTex K. Monroe
Life of this patent
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Abstract
A vertical amplifier provides a deflection or yoke current independent of the yoke impedance or other impedances in the yoke current path. The amplifier comprises a general-purpose operatonal amplifier that develops an output voltage in a manner that maintains identical voltages at its inverting and non-inverting inputs. A feedback resistance is connected in the yoke current path, thereby developing a voltage indicative of the yoke current. As a result, the yoke current waveform can be made identical to or a desired variation of a current commanding voltage waveform applied to the non-inverting input. A particular variation of the feedback resistance transforms an S-shaped current waveform into a sawtooth voltage waveform, thereby providing the desired deflection linearity.
Claims7
In a television receiver having a vertical deflection yoke winding and a constant-current vertical amplifier circuit for developing, in response to a current-commanding signal at the amplifier input, a yoke current independent of the yoke impedance, an improved current-sensing feedback resistance comprising:
- a first resistor connected between one end of the yoke winding and a reference potential;
- a parallel-connected second resistor and first diode connected at one end to the junction of the yoke winding and first resistor;
- a third resistor connected between another end of the parallel-connected second resistor and first diode and said potential whereby a feedback voltage is developed across the third resistor and a greater proportion of feedback voltage is developed in response to greater amplitudes of yoke current whereby a substantially S-shaped yoke current waveform is developed in response to a substantially sawtooth current-commanding signal.
In a television receiver having a deflection yoke winding and a constant-current amplifier circuit for developing a yoke current independent of the yoke impedance in response to a current-commanding signal applied to a first amplifier input, an improved current-sensing feedback resistance coupled to a second amplifier input and comprising:
- first means connected to yoke winding for developing a voltage in proportion to the yoke current;
- dividing means, including a parallel-connected diode and first resistor connected at one end to the junction of the yoke winding and first means and a second resistor coupled between the other end of the parallel connected diode and first means and a reference potential and coupled to the second amplifier input, said means for developing a feedback voltage in response to the yoke current whereby a greater proportion of feedback voltage is developed in response to greater amplitudes of yoke current so that substantially S-shaped yoke current waveform is developed in response to a substantially sawtooth current-commanding signal.
In a television receiver having a deflection yoke winding and a constant-current amplifier circuit for developing a yoke current independent of the yoke impedance in response to a current-commanding signal applied to a first amplifier input, an improved current-sensing feedback resistance coupled to a second amplifier input and comprising:
- (a) first means connected to yoke winding for developing a voltage in proportion to the yoke current;
- and
- (b) dividing means connected between the junction of the first means and the yoke winding and a reference potential for developing a feedback voltage in response to the yoke current, said dividing means comprising:
- parallel-connected first and second diodes connected at one end to the junction of the yoke winding and first means;
- a first resistor series-connected to the other end of the diodes;
- a second resistor connected in parallel to the series-connected resistor and diodes;
- a third resistor connected to the reference potential and coupled through the second resistor to the junction of the yoke winding and first means whereby a greater proportion of feedback voltage is developed in response to greater amplitudes of yoke current so that substantially S-shaped yoke current waveform is developed in response to a substantially sawtooth current-commanding signal.
Dependencies are inferred from the claim text.