Abstract: A compressor for compressing a refrigerant containing a substance having a double bond, a condenser for condensing the refrigerant by heat exchange, expanding means for decompressing the condensed refrigerant, and an evaporator for evaporating the decompressed refrigerant by heat exchange are connected by piping so as to configure a refrigerant circuit through which the refrigerant is circulated, and control means is provided for controlling an operation of the refrigerant circuit so that a pressure of the refrigerant in the refrigerant circuit becomes less than a critical pressure of the substance having the double bond.

Abstract: An automatic tracking speed compensating drive unit 4a for a rotary drum VCR includes a deflection control coil 44 wound around a bobbin 43 mounted to a magnetic yoke assembly 47 by upper and lower spring plates 200, 100. The lower plate has a larger spring constant than the upper plate such that the "softer" upper plate absorbs substantially all thermally induced axial elongations of the bobbin, thereby avoiding tracking errors of a magnetic r/w head 5 mounted on a tab extending outwardly from the "stiffer" lower spring plate.