| 摘要 |
1,004,266. Transistor inverter oscillators. WESTERN ELECTRIC CO. Inc. Dec. 7, 1961 [Dec. 9, I960], No. 43806/61. Heading H3T. [Also in Division H2] A transistor oscillator utilizes current and voltage regenerative feed-back. Upon switching on the inverter oscillator shown, current through resistor 116 renders transistor 161 conducting and the resulting regenerative feedback via transformers 403 and 408 maintains it so and ensures 102 is cut off. Initially all the feed-back current flows through the primary winding of transformer 108 since the load on the secondary makes the primary appear to be resistive, but an increasing amount is by-passed through circuit 112, 113 until, after a time dependent upon the time constant of 112, 113, so much is by-passed that the feed-back is insufficient to maintain transistor 161 increasingly conductive. By regenerative action transistor 102 then becomes conductive, 101 is cut off and in this manner the circuit oscillates. Transformer 111 being in series with the load provides current feed-back while resistor 114 or a seriesresonant circuit (Fig. 4, not shown) provides voltage feed-back. The timing circuit 112, 113 could be connected elsewhere in the circuit and could be omitted if a gapped transformer is used. The transistors may alternatively be arranged in common base or common collector configuration or a bridge circuit could be used (Figs. 3, 4 and 5, not shown). In the latter circuit a choke capacitor filter may be connected in the D.C. supply and a rectifier connected across the choke to prevent excessive voltage surges on switching on. |
