Short-wave treatment apparatus

Abstract

Abstract 743,884. Electro-medical apparatus. SIEMENS-REINIGER-WERKE AKT.-GES. Sept. 4, 1953 [Sept. 10, 1952], No. 24506/53. Class 81(2). [Also in Group XL(c)] In radio frequency heating or diathermy apparatus subject to variations in tuning of the load circuit due, e.g. to movement of the patient or object to be treated, the load tuning is constantly cyclically varied by a motor M driving a load circuit capacitor C 2 and the speed of the motor is arranged to be reduced at resonance by a relay A responsive to the difference between anode and grid currents at resonance of the oscillator valve V 1 , measured as a difference in voltage across anode and grid circuit resistors Ra, Rg. To this end the relay A introduces a series resistor P in the motor drive. At the same time the relay may also increase the anode voltage by alternating the tapping of the transformer secondary which energizes the valve V 1 .

Inventors

No inventors recorded.

Bibliographic Details