Deflection coil driver apparatus

A deflection coil driver apparatus comprising:

• a deflection coil;
• a first power transistor connected such that current is coupled from a positive voltage source to said deflection coil when said first power transistor is turned on;
• a second power transistor connected such that current is coupled from a negative voltage source to said deflection coil when said second power transistor is turned on;
• a third power transistor connected such that current is coupled from said deflection coil to ground when said third power transistor is turned on;
• means for generating a first current when an input signal has one range of values and for generating a second current when said input signal has a second range of values;
• means for coupling said first current to said first power transistor such that it goes on so long as said first current remains on;
• and
• switch means for sensing the voltage at said terminal and for causing said second current to be coupled to said third power transistor when said deflection coil voltage is positive, thereby turning on said third power transistor so long as said second current remains coupled thereto, and for causing said second current to be coupled to said second power transistor when said deflection coil voltage is negative, thereby turning on said second power transistor so long as said second current remains coupled thereto.

A deflection coil driver apparatus comprising:

• a deflection coil connected between a first terminal and a second terminal;
• an amplifier for amplifying an input signal;
• a first power transistor connected such that current is coupled from a positive voltage source to said first terminal when said first power transistor is turned on;
• a second power transistor connected such that current is coupled from a negative voltage source to said first terminal when said second power transistor is turned on;
• a third power transistor connected such that current is coupled from said first terminal to ground when said third power transistor is turned on;
• means for generating a first current when said amplified input signal has one polarity and for generating a second current when said amplified input signal has the opposite polarity;
• means for coupling said first current to said first power transistor such that it goes on so long as said first current remains on;
• switch means for sensing the voltage at said first terminal and for causing said second current to be coupled to said third power transistor when said first terminal voltage is positive, thereby turning on said third power transistor so long as said second current remains coupled thereto, and for causing said second current to be coupled to said second power transistor when said first terminal voltage is negative, thereby turning on said second power transistor so long as said second current remains coupled thereto;
• means connected to said second terminal for sensing the current through said coil and for coupling said sensed current to said amplifier, said amplifier acting in response thereto to generate an error correction signal in said amplified input signal.

A deflection coil driver apparatus comprising:

• a deflection coil connected between a first terminal and a second terminal;
• an amplifier for amplifying an input signal;
• means connected to said second terminal for sensing the current through said coil and for coupling said sensed current to said amplifier, said amplifier acting in response thereto to generate an error correction signal in said amplified input signal;
• a first power transistor connected such that current is coupled from a positive voltage source to said first terminal when said first power transistor is turned on;
• a second power transistor connected such that current is coupled from a negative voltage source to said first terminal when said second power transistor is turned on;
• a third power transistor connected such that current is coupled from said first terminal to ground when said third power transistor is turned on;
• class B amplifier means, including a first class B biased transistor and a second class B biased transistor for generating a first current through said first class B transistor when said amplified input signal has one range of value, said second class B transistor generating a second current when said amplified input signal has a second range of values;
• means for coupling said first current to said first power transistor such that it goes on so long as said first current remains on;
• switch means for sensing the voltage at the first terminal and for causing said second current to be coupled to said third power transistor when said first terminal voltage is positive, thereby turning on said third power transistor so long as said second current remains coupled thereto, and for causing said second current to be coupled to said second power transistor when said first terminal voltage is negative, thereby turning on said second power transistor so long as said second current remains coupled thereto.