A control apparatus for an air conditioning system has an outdoor unit with a compressor, a condenser and a plurality of motorized valves installed to a plurality of branch pipings. A plurality of indoor units having, a plurality of indoor thermoswitches, a microcomputer, and a drive circuit for driving...http://www.google.com/patents/US4812997?utm_source=gb-gplus-sharePatent US4812997 - Control apparatus for an air conditioning system
