Abstract: A power control device for a microwave cooking oven includes a regulator of the anode voltage of the magnetron and a heater voltage source. The anode voltage regulator includes a d.c. voltage bridge-type converter, a transformer, a rectifier and a filter. The heater voltage source includes a half-bridge d.c. to a.c. voltage converter. The half-bridge and bridge converters are controlled each by signals coming from the respective generators of pulse sequences.

Abstract: The method of thermal-mine recovery of oil and fluent bitumens or kerogens includes providing a system of mine workings above an oil-bearing formation and drilling from these workings and from the ground surface a series of injection wells into the oil-bearing formation. An operation gallery is provided within the oil-bearing formation, from which a system of horizontal and inclined recovery wells is drilled. Then a heat carrier is positively injected into the oil-bearing formation to heat it to a temperature whereat the oil attains the required fluidity within the formation. Then a fluid is charged into the formation to force the oil from the oil-bearing formation into the horizontal and inclined recovery wells, toward the operation gallery, from which the oil is directed to the ground surface.