Compressor head, internal discriminator, external discriminator, manifold design for refrigeration recovery apparatus

A cylinder head for a compressor for a refrigerant recovery system, said compressor being constructed and arranged to perform a suction stroke and a discharge stroke, said cylinder head comprising:

• a) an inlet port, a discharge port, an inlet orifice, and a discharge orifice;
• b) an inlet passage in communication with said inlet port and said inlet orifice;
• c) a discharge passage in communication with said discharge port and said discharge orifice;
• d) a first ball valve positioned in said inlet passage, said first ball valve comprising a first actuating member, a first ball, and a first seat proximate to said inlet port;
• and
• e) a second ball valve positioned in said discharge passage said second ball valve comprising a second actuating member, a second ball, and a second seat proximate to said discharge orifice, wherein said first actuating member is constructed and arranged to actuate said first ball against said first seat during said discharge stroke closing said inlet passage and said second actuating member being constructed and arranged to actuate said second ball against said second seat during said suction stroke closing said discharge passage.

A vacuum sensor comprising:

• a first transistor IC including a first heating transistor which generates a fixed amount of heat and a second temperature measuring transistor which measures a corresponding temperature rise due to the heat generated in the first transistor, the first transistor IC being thermally connected to a metal mass;
• a second transistor IC including a third temperature measuring transistor which measures the ambient temperature of the metal mass;
• a regulated power supply connected to the collector of the first transistor and the collector of the third transistor, which causes a forward voltage at the emitters of the second and third transistors which varies with temperature;
• a computation circuit connected to the vacuum sensor;
• whereby the difference between the forward voltages at the emitters of the second and third transistors is converted into a vacuum measurement.