| 摘要 |
1,153,910. Starting inverters or frequency changers. ELIN-UNION A.G. FUR ELEKTRISCHE INDUSTRIE. 24 Nov., 1966 [26 Nov., 1965], No. 52671/66. Heading H2F. [Also in Division H3] Oscillation of a self-oscillating inverter having a resonant circuit 1, 2, is initiated by interrupting an auxiliary current in the inductor 2. As shown, the winding 2 of an inductive heater is supplied with current at 1.5 to 4kc/s from an inverter comprising a bridge of four thyristors 5 ... 8 supplied with direct current via an inductor 3. Initially, thyristors 4 6, 7 should be conductive giving inverse currents is and i H , in inductive load 2, the latter being derived from a transformer 11 via an inductor 10. Oscillation is initiated by triggering thyristor 9 which turns off thyristor 4, creating a ringing oscillation in the circuit 1, 2. Control circuits (not shown), are provided so that appropriate pairs of thyristors 5... 8 are alternately turned on in sequence. Thyristor 9 is finally extinguished by opening contacts 16. The D.C. supply for the inverter may be derived from a controlled rectifier supplied from alternating current mains so as to form a frequency changer. |
