Method of and control circuit for admixing air

Claim 2

An electric control circuit including means which sense an air heat-related parameter for generation of signals which influence position of a control member which regulates the admixing of outside air into recirculating air in ventilation or air conditioning systems where, during winter operation, the outside air portion of the mixture, starting with a first predetermined onset point, is smaller, the lower is the air heatrelated sensed parameter; and where, during summer operation, the outside air portion of the mixture, starting with a second predetermined onset point, is smaller, the higher is the air heat-related sensed parameter; said electric control circuit comprising a first channel for winter operation and a second channel for summer operation, each of said channels being constantly operational, said first channel being responsive to said sensed heat-related parameter only below said first onset point for providing a first output signal, and said second channel being responsive to said sensed heat-related parameter only above said second onset point for providing a second output signal; means responsive to the output signals from said first channel and said second channel for adjusting the position of said control member; whereby the circuit function automatically changes between winter and summer operational modes as required without aid from any special switching device.

Claim 3

An electric control circuit including means which sense an air heat-related parameter for generation of signals which influence position of a control member which regulates the admixing of outside air into recirculating air in ventilation or air conditioning systems where, during winter operation, the outside air portion of the mixture, starting with a first predetermined onset point, is smaller, the lower is the air heat-related sensed parameter; and where, during summer operation, the outside air portion of the mixture, starting with a second predetermined onset point, is smaller, the higher is the air heat-related sensed parameter; said electric control circuit comprising a first channel for winter operation and a second channel for summer operation, each of said channels being constantly operational, said first channel being responsive to said sensed heat-related parameter only below said first onset point for providing a first output signal, and said second channel being responsive to said sensed heat-related parameter only above said second onset point for providing a second output signal; means responsive to the output signals from said first channel and said second channel for adjusting the position of said control member; whereby the circuit function automatically changes between winter and summer operational modes as required without aid from any special switching device.

Claim 4

An electric control circuit including means which sense an air heat-related parameter for generation of signals which influence position of a control member which regulates the admixing of outside air into recirculating air in ventilation or air conditioning systems where, during winter operation, the outside air portion of the mixture, starting with a first predetermined onset point, is smaller, the lower is the air heat-related sensed parameter; and where, during summer operation, the outside air portion of the mixture, starting with a second predetermined onset point, is smaller, the higher is the air heat-related sensed parameter; said electric control circuit comprising a first channel for winter operation and a second channel for summer operation, each of said channels being constantly operational, said first channel being responsive to said sensed heat-related parameter only below said first onset point for providing a first output signal, and said second channel being responsive to said sensed heat-related parameter only above said second onset point for providing a second output signal; means responsive to the output signals from said first channel and said second channel for adjusting the position of said control member; whereby the circuit function automatically changes between winter and summer operational modes as required without aid from any special switching device.

Claim 5

An electric control circuit as defined in claim 1, wherein said means which sense an air heat-related parameter comprise means for sensing the heat-related parameter of an air mixture within said system.

Claim 6

An electric control circuit as defined in claim 1, wherein said means which sense an air heat-related parameter comprise means for sensing the heat-related parameter of outside air.

Claim 7

An electric control circuit as defined in claim 1, wherein said means which sense an air heat-related parameter comprise temperature sensing means.

Claim 8

An electric control circuit as defined in claim 4, wherein said temperature sensing means senses temperature of air mixture within said system.

Claim 9

An electric control circuit as defined in claim 4, wherein said temperature sensing means senses temperature of outside air.

Claim 10

An electric control circuit as defined in claim 2, wherein said means responsive to the output signals from said first channel and said second channel includes summation circuit means whose output signal determines the position of said control member.

Claim 11

An electric control circuit as defined in claim 1, wherein said means which sense an air heat-related parameter comprise a single, common air temperature sensor operatively associated with both said first channel and said second channel.

Claim 12

An electric control circuit as defined in claim 8, wherein said temperature sensor senses temperature of outside aIr.

Claim 13

An electric control circuit as defined in claim 8, wherein said temperature sensor senses temperature of air mixture within said system.

Claim 14

An electric control circuit as defined in claim 1, wherein said means which sense an air heat-related parameter comprise distinct, separate air temperature sensors in each of said channels, each channel being provided with respective rectifying means.

Claim 15

An electric control circuit as defined in claim 11, wherein each of said sensors sense temperature of outside air.

Claim 16

An electric control circuit as defined in claim 11, wherein each of said sensors sense temperature of air mixture within said system.

Claim 17

An electric control circuit as defined in claim 1, wherein said first channel is operatively arranged to provide an output signal which is zero with respect to a reference for the heat-related parameter above said first onset point, and said second channel is operatively arranged to provide an output signal which is zero with respect to said reference for the heat-related parameter below said second onset point.

Claim 18

An electric control circuit as defined in claim 14, wherein said means which sense an air heat-related parameter comprise means for sensing temperature of outside air.

Claim 19

An electric control circuit as defined in claim 14, wherein said means which sense an air heat-related parameter sense temperature of air mixture within said system.

Claim 20

An electric control circuit as defined in claim 1, further comprising means for sensing temperature of exhaust air, and means responsive to output from said means for sensing temperature, for changing automatically said second onset point in dependence on exhaust air temperature.

Claim 21

An electric control circuit as defined in claim 1, further comprising means for sensing temperature of exhaust air, and means, responsive to output from said means for sensing temperature, for changing automatically said first onset point in dependence on the exhaust air temperature.

Claim 22

An electric control circuit according to claim 1, further comprising means for limiting quantity of outlet air to a given value over a period of time.

Claim 23

An electric control circuit according to claim 19, wherein said means for limiting is operatively arranged to limit the outside air quantity to a given desired minimum value.

Claim 24

An electric control circuit according to claim 19, wherein said means for limiting is operatively arranged to limit the outside air quantity to a given desired maximum value.

Claim 25

An electric control circuit according to claim 19, wherein said means for limiting comprise a limiting circuit connected to receive output from said first channel and said second channel via summing circuit means.

Claim 26

An electric control circuit as defined in claim 1, including circuit means for adjusting slope of at least one portion of operational characteristic curve of circuit, without changing said onset points.

Claim 27

An electrical control circuit as defined in claim 1, wherein said means which sense an air heat-related parameter comprise means for sensing heat content of air.

Claim 28

An electrical control circuit as defined in claim 24, wherein said means for sensing heat content sense heat content of outside air.

Claim 29

An electrical control circuit as defined in claim 24, wherein said means for sensing heat content sense heat content of air mixture within the system.

Claim 30

An electric control circuit as defined in claim 1, including automatically operating means responsive to temperature of exhaust air for changing the onset point of variable throttling of outside air supply.

Claim 31

An electric control circuit as defined in claim 27, including means for maintaining an approximately constant difference between temperature of the exhaust air and the temperature of the outside air.