Abstract: A raster position adjusting circuit for controlling the raster position on a CRT, the circuit being equipped with a constant-current supply source and a voltage-controlled type current supply source which are coupled to each other. The drawing current of the voltage-controlled type current supply source is arranged to be controllable in accordance with the output voltage from a digital-to-analog converter, thereby controlling the emitter-base voltages of first and second transistors connected to a junction point between both the current supply sources. This control of the emitter-base voltages of the first and second transistors allows the control of the direction and value of a current flowing through a horizontal deflecting coil, thereby effecting the raster position adjustment.

Abstract: A cathode clamping circuit apparatus with digital control comprises; a variable voltage source for generating the bright voltage and cathode clamping circuits for producing dc component voltages for color component signals respectively. Each of the cathode clamping circuits has: a capacitor for coupling one of color component signals to an output terminal; the shunt regulator for generating the sub-bright voltage in accordance a current signal, the bright and the sub-bright voltages being summed to produce the dc component voltages by connecting the variable voltage source to the shunt regulator in series; the variable current source for producing the current signal in accordance with a voltage signal; a d/a converter responsive to a control signal for producing the voltage signal; a transistor for clamping the color component signal with the sum voltage of the bright voltage and sub-bright voltages in response to the clamp pulse produced from the color component signals R, G.