| 摘要 |
1,075,078. Switching circuits. BIVIATOR S.A. Oct. 30, 1964 [Nov. 2, 1963 (2)], No. 44339/64. Addition to 1,035,518. Heading H3T. [Also in Division H2] A reversible input signal is applied to terminals 1, 2, connected to the bases of NPN transistors 3, 4, which are coupled with PNP transistors 5, 6, forming part of a bridge circuit comprising source 7 and balancing potentiometer 8. The output of the bridge circuit is connected to a modulator circuit including complementary transistors 11, 12, which are controlled by alternating voltages derived from oscillator 15 through transformer windings 13, 14. When the potential difference at terminals 1, 2 is such that terminal 9 is positive relative to terminal 10, current passes through transistor 12 and diode 17 to afford an alternating voltage input to amplifier 19 providing four independent signals in circuit 20 for control of the transistors in a reversing bridge of the type described in Specification 1,035,518. When the potential at terminals 9, 10, is reversed, transistor 11 acts as a modulator and amplifier 18 operates circuit 20 for opposite operation of the reversing bridge. In another arrangement, the emitter of each of the complementary transistors is connected through a voltage source to one output terminal of the bridge 5-8, while the base of each of the transistors is connected to the other output terminal. The independent output circuits of the complementary transistors are connected to oscillators for energizing the output circuit, Fig. 3 (not shown). Balancing potentiometers may be associated with the sources. In a further embodiment, voltage sources are connected into the collector circuits of the complementary transistors, Fig. 5 (not shown). The input bridge circuit may be replaced by a valve pre-amplifier, the input terminals 1, 2 being connected to the grid circuit of a valve coupled to two output valves arranged as cathode followers, Fig. 2 (not shown). |
