GB874958A - Improvements relating to dielectric heating apparatus - Google Patents

Abstract

874,958. Valve oscillator circuits. BAZIN, R. E. Feb. 11, 1958 [Feb. 25, 1957], No. 6307/57. Class 40(6) A di-electric heating oscillator comprises a cavity resonator having inner and outer members and an oscillator valve mounted in or on the inner member with its anode connected to the outer member or to the high potential end of the inner member and a grid or filament lead arranged in close proximity to the inner member so that it takes up the voltage gradient of said inner member. In Fig. 1 the oscillator comprises a cavity resonator having inner and outer members 2, 1 and an oscillator valve 5 mounted on a bracket on the inner member with its anode connected to the outer member at 12, its grid connected to the inner member at 7 and its cathode connected to the inner member at 10. Power may be taken from a variable capacitor coupling 14, from a loop associated with leads 14b or from a direct connection 14c. The grid and filament leads 8, 9 are taken through the member 2 and along the inner wall of member 1. Cooling may be effected by a fan 16 or by using the chimney effect of the resonator. The power output may alternatively be taken from a coaxial line the inner conductor of which is formed by an extension of member 2 taken through the upper wall. (Fig. 3, not shown). The plates of the heater may be formed by upper wall 4 and a further plate connected to the extension of member 2 (Fig. 4, not shown).