Television display apparatus provided with a circuit arrangement for generating a sawtooth deflection current

Claim 2

Television display apparatus provided with a circuit arrangement for generating a sawtooth deflection current through a line deflection coil, said coil being a part of a network furthermore comprising at least a trace capacitor, a retrace capacitor and a first diode through which the deflection current flows during part of the trace time of the sawtooth current while said current flows through a second diode and a controllable switch during the other part of the trace time, a primary winding of a transformer being incorporated between a direct voltage source and the switch and its secondary winding being connected through a third diode to the network, characterized in that the circuit arrangement includes switching means for blocking any current in the second diode in the retrace time.

Claim 3

Television display apparatus as claimed in claim 1 in which the third diode is connected to the retrace capacitor, characterized in that the ratio between the number of turns on the secondary winding and the number of turns on the primary winding is at least equal to approximately

Claim 4

Television display apparatus as claimed in claim 1, in which the third diode is connected to the trace capacitor, characterized in that the ratio between the number of turns on the secondary winding and the number of turns on the primary winding is at least equal to approximately (1.2/069 / Alpha where Alpha is the ratio between the retrace voltage and its direct voltage component.

Claim 5

Television display apparatus as claimed in claim 1, characterized in that said switching means comprises a transistor arranged in series with the second diode while the base of said transistor receives a blocking voltage in the retrace time.

Claim 6

Television display apparatus as claimed in claim 4, characterized in that the control means of the transistor includes a further secondary winding of the transformer.

Claim 7

Television display apparatus as claimed in claim 1 in which the second diode is connected to the controllable switch, characterized in that a fourth diode is arranged in series with the primary winding.

Claim 8

Television display apparatus as claimed in claim 6, characterized in that the fourth diode is shunted by a resistor.

Claim 9

A circuit arrangement for generating a sawtooth deflection current through a line deflection coil powered from a direct voltage source, said circuit comprising a trace capacitor to couple to said coil, a retrace capacitor coupled to said trace capacitor and a first diode coupled to said retrace capacitor through which the deflection current flows during part of the trace time of the sawtooth current, a second diode coupled to said retrace capacitor, a controllable switch coupled to said trace capacitor, said current flowing through said controllable switch and said second diode part of the trace time, a transformer having a primary winding to coupled to said direct voltage source and coupled to the switch, and a secondary winding, a third diode coupled to said secondary winding and one of said capacitors, and switching means coupled to said second diode for blocking any current in the second diode in the retrace time.

Claim 10

A circuit arrangement for generating a sawtooth deflection current through a line deflection coil powered from a direct voltage source, said circuit comprising a trace capacitor to couple to said coil, a retrace capacitor coupled to said trace capacitor and a first diode coupled to said retrace capacitor through which the deflection current flows during part of the trace time of the sawtooth current, a second diode coupled to said retrace capacitor, a controllable switch coupled to said trace capacitor, said current flowing through said controllable switch and said second diode part of the trace time, a transformer having a primary winding to coupled to said direct voltage source and coupled to the switch, and a secondary winding, a third diode coupled to said secondary winding and one of said capacitors, and switching means coupled to said second diode for blocking any current in the second diode in the retrace time.