| 摘要 |
1,151,714. Thyristor sawtooth generating circuits. RADIO CORPORATION OF AMERICA. 13 July, 1966 [6 Aug., 1965], No. 31415/66. Heading H3T. In a line output stage, for a television receiver, a series arrangement of capacitors 27, 28; deflection coils 30 and thyristor 22 are effectively connected in parallel, an auxiliary low-voltage supply is derived from a resistance/ capacitance citcuit 26a, 26b connected in series with the thyristor 22. As described, the circuit is supplied from a 140 v. source 32 and provides 20-30 v. across capacitor 26a for the heater of the cathode-ray tube and for the vertical and horizontal oscillators (not shown). Diode 31 clamps the deflection coils 30 and the capacitor 29 to supply 32 during each trace portion so that an S-wave of current flows in deflection coils 30. When thyristor 22 is triggered by a pulse from the line oscillator, capacitor 27 is resonantly discharged via inductor 25 and capacitor 26a. The rapid fall in voltage across capacitor 27 is coupled by capacitor 28 to reverse bias diode 31, initiating the flyback. Thyristor 22 becomes non-conductive when the voltage across it reverses, terminating the flyback and allowing capacitors 27, 28 to recharge via inductors 33, 34. Circuit 35, 36 prevents ringing. |
