Fan and clutch control circuit for an air conditioner

Claim 2

An electronic circuit for controlling the operation and speed of a fan of an air conditioner over a preselected temperature range and the operation of a compressor of the air conditioner at selected temperatures, said circuit comprising speed control circuit means having a return air temperature sensor means connected thereto to supply a control signal to said speed control circuit means corresponding to the air being sensed in a return air section of the air conditioner, power amplifier circuit means connected to said speed control circuit means to receive an output signal from said speed control circuit means and provide an amplified output signal, a fan motor connected to said power amplifier circuit means and adapted to be operated thereby at a speed in accordance with the amplified output signal, clutch control circuit means having an evaporator coil temperature sensor means connected thereto to supply another control signal to said clutch control circuit means corresponding to the temperature of the evaporator coil, switch means connected to said clutch control circuit means to receive an output signal from said clutch control circuit means and operate said switch means, an electrically operated clutch connected to said switch means for operation thereby to operate the air conditioner compressor when said switch means is operated, and override circuit means connected between said power amplifier circuit means and said clutch control circuit means to automatically deenergize said electrically operated clutch when the temperature drops a prescribed amount below a low side of the preselected temperature range.

Claim 3

An electronic circuit according to claim 1 wherein voltage regulator circuit means is connected to said override circuit means and said clutch control circuit means to control the voltage level thereto.

Claim 4

An electronic circuit according to claim 1 wherein selector circuit means is connected to said speed control circuit means to select the preselected temperature range.

Claim 5

An electronic circuit according to claim 1 wherein by-pass circuit means is connected to said fan motor and said electriCally operated clutch to operate said fan motor and said electrically operated clutch directly instead of by said speed control circuit means, power amplifier circuit means, clutch control circuit means and said switch means.

Claim 6

An electronic circuit according to claim 1 wherein said sensor means comprise thermistor means.

Claim 7

An electronic control circuit for controlling operation of a first member over a preselected temperature range and a second member at selected temperatures comprising first control circuit means having first temperature sensing means connected thereto to supply a control signal to said first control circuit means corresponding to the ambient condition of an area adjacent the first member being sensed by said first temperature sensing means, power amplifier circuit means connected to said first control circuit means to receive an output signal from said first control circuit means and provide an amplified output signal, first load means connected to said power amplifier circuit means and adapted to be operated thereby in accordance with the amplified output signal to operate the first member, second control circuit means having a second temperature sensing means connected thereto to supply another control signal to said second control circuit means corresponding to the ambient condition of another area adjacent the second member being sensed by said second temperature sensing means, switch means connected to said second control circuit means to receive an output signal from said second control circuit means and operate said switch means, second load means connected to said switch means and adapted to be operated thereby in accordance with the selected temperatures when said switch means is operated, and override circuit means connected between said power amplifier circuit means and said second control circuit means to automatically deenergize said second load means when the temperature drops a prescribed amount below a low side of the preselected temperature range.

Claim 8

An electronic control circuit for controlling operation of a first member over a preselected temperature range and a second member at selected temperatures comprising first control circuit means having first temperature sensing means connected thereto to supply a control signal to said first control circuit means corresponding to the ambient condition of an area adjacent the first member being sensed by said first temperature sensing means, power amplifier circuit means connected to said first control circuit means to receive an output signal from said first control circuit means and provide an amplified output signal, first load means connected to said power amplifier circuit means and adapted to be operated thereby in accordance with the amplified output signal to operate the first member, second control circuit means having a second temperature sensing means connected thereto to supply another control signal to said second control circuit means corresponding to the ambient condition of another area adjacent the second member being sensed by said second temperature sensing means, switch means connected to said second control circuit means to receive an output signal from said second control circuit means and operate said switch means, second load means connected to said switch means and adapted to be operated thereby in accordance with the selected temperatures when said switch means is operated, and override circuit means connected between said power amplifier circuit means and said second control circuit means to automatically deenergize said second load means when the temperature drops a prescribed amount below a low side of the preselected temperature range.

Claim 9

An electronic control circuit according to claim 6 wherein said switch means comprises serially connected transistor means.

Claim 10

An electronic control circuit according to claim 6 wherein voltage regulator circuit means is connected to said override circuit means, said first control circuit means, and said second control circuit means to control the voltage level thereto.

Claim 11

An electronic control circuit according to claim 6 wherein by-pass circuit means is connected to said first and second load means to operate these load means directly instead of by said first and second circuit control means, power amplifier circuit means and said switch means.