Automotive air conditioning system controlled by damped pressure switch

Abstract From the Canadian patent

The electrically operated clutch controlling operation of the compressor is regulated by a damped pressure switch. The pressure switch has a diaphragm which moves in response to pressure variation to actuate the switch. The force acting on the diaphragm is opposed by spring force. The housing is provided with a damping chamber between the diaphragm chamber and the restricted passage in the inlet. The restricted passage is the clearance between the hole drilled in the metal insert and the wire fixed in the hole. The restriction is selected relative to the damping chamber so the switch will not cycle more than four times per minute when sensing pressure at the outlet of a finned coil …