| 摘要 |
1,254,205. Transistor sawtooth circuits. JAN WESSELS RADIOFABRIKK RADIONETTE A/S. 19 Feb., 1969 [24 Feb., 1968], No. 9076/69. Heading H3T. A line deflection circuit for a cathode-ray tube comprises a pair of series-connected transistors T 1 , T 2 connected via an inductor or transformer 4 across a D.C. supply 3, a deflection coil 5 in series with a blocking capacitor 6 and being tuned by capacitor 7 being connected across one of the transistors. As described, transistors T 1 , T 2 are turned on during the second part of each sweep by pulses from a source 1, and turned off at the end of each sweep so that the energy in the deflection coil 5 is resonantly transferred to capacitor 7. After one-half cycle, diode 11 becomes conductive so that a linear build up of current occurs in coil 5, forming the beginning of the next sweep. A feedback loop 9 is provided to alter the conductive period of T 1 (relative to that of T 2 ) and so maintain the sweep amplitude constant. Diodes 11 and 12 may be replaced by the base-collector junction of T 2 . |
