GB639470A - A device for repeated starting and stopping of an oscillation generator - Google Patents

Abstract

639,470. Interrupting high-frequency oscillations. STIVEN, J. June 30, 1947, No. 17169. Convention date, Aug. 27, 1946. [Class 40 (v)] Switching means for interrupting the operation of valve generators, such as are used for electric heating of metals, are arranged to start the generator by first opening a short circuit across the grid leak and then short-circuiting a condenser connected between the leak and ground; whereas for stopping the generator, the leak is first shorted and then the short across the condenser is removed. As shown in Fig. 1. the control switch 9 is closed to start the generator, the relay 8 lifting the switch 2 to open the short across the leak 5 and to connect at 7 the relay 10 in the grid circuit. The contact 6 is thus closed in parallel with the contact 7 and the generator starts up. To stop the generator, control switch 9 is opened, thus releasing the switch 2 to open the contact 7 and close contact 1. The grid is now earthed by the condenser 3 for oscillatory voltage, the oscillation ceases and the absence of grid current releases the switch 6. In a modified circuit (Fig. 2, not shown), the coil 10 is replaced by a coil in circuit with further contacts controlled by the coil 8. The Specification as open to inspection under Sect. 91 comprises also a further modification, Fig. 3 (Cancelled), in which the contacts 13, 14 are opened and closed by spaced stop members attached to a link 17 suspended from an operating lever 15, the movable contacts being pressed apart by a coiled spring. When the link 17 has been lifted to start the oscillator, the spring- controlled roller R rides up the guide G to complete the short-circuit across the condenser 3. This subject-matter does not appear in the Specification as accepted.