| 摘要 |
1,042,269. Generating radio frequency oscillations. WESTINGHOUSE ELECTRIC CORPORATION. June 3, 1964 [.Tune 28, 1963], No. 22991/64. Heading H3B. [Also in Division H2] In a high power signal generator (Fig. 1) operating in the ultrasonic frequency region, e.g. for use in very low frequency (VLF) radio transmitters, sonar and similar apparatus. a substantially sinusoidal output voltage is obtained across a resonant circuit 20 by " ring- ing " the circuit with pulses derived by successively charging and discharging a pulse forming network 13 through silicon controlled rectifiers 12 and 14 respectively. The network 13 comprises an inductance and a capacitance (Fig. 2, not shown) and may incorporate the charging inductance 19 associated with SCR 12. The network 13 is connected to the centre tap or upper end (Fig. 2, not shown) of a coil 22 forming part of the resonant circuit 20. In a higher power embodiment (Fig. 2, not shown) each of the SCR's 12 and 14 is replaced by a group of SCR's arranged in parallel branches A, B, C, each branch comprising two or more SCR's in series for high voltage working. All the rectifiers in a branch are arranged to be triggered together, and the branches are arranged to be triggered in sequence. Trigger pulses are provided in both embodiments by an external generator (shown as 30 in Fig. 1). |
