# US 7,464,561 B1 · Unitary control for air conditioner and/or heat pump > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,464,561 B1 - Document ID: US7464561B1 - Status: Granted - Kind: B1 - Application number: 11/514,607 - Filed: 2006-09-01 - Granted: 2008-12-16 - Earliest claimed: 2003-07-25 - Assignees: Emerson Electric Co. - Inventors: William P. Butler; Dean A. Drake; Nagaraj B. Jayanth - Web page: https://patentgrep.com/patent/US7464561B1 ## CPC - F24F 11/63: Electronic processing - F24F 11/83: by controlling the supply of heat-exchange fluids to heat-exchangers - F24F 11/84: using valves - F24F: AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING (removing dirt or fumes from areas where they are produced B08B15/00; vertical ducts for carrying away waste gases from buildings E04F17/02; tops for chimneys or ventilating shafts, terminals for flues F23L17/02) ## Abstract A unitary control for operating at least the fan and compressor of a climate control apparatus in response to signals received from a thermostat. The unitary air conditioning control includes a circuit board, a microprocessor on the circuit board, a first relay on the circuit board operable by the microprocessor, to connect a fan connected thereto to line voltage, and having first and second contacts at least one of which is connected to the microprocessor; and a second relay on the circuit board operable by the microprocessor, to connect a compressor connected thereto to line voltage, and having first and second contacts connected to the microprocessor. ## Claims ### Claim 1 A unitary control for operating at least the fan and compressor of a climate control apparatus in response to signals received from a thermostat, the unitary air conditioning control comprising: a circuit board; a microprocessor on the circuit board; a first relay on the circuit board operable by the microprocessor, to connect a fan connected thereto to line voltage, and having first and second contacts at least one of which is connected to the microprocessor; a second relay on the circuit board operable by the microprocessor, to connect a compressor connected thereto to line voltage, and having first and second contacts connected to the microprocessor; the microprocessor configured to operate the second relay relative to the phase of the line voltage and without input as to arcing duration, if any, to reduce arcing at the contacts of the second relay. ### Claim 2 (depends on 1) The unitary control according to claim 1 further comprising a current transformer on the circuit board in series with the first relay and connected to the microprocessor, for generating a signal related to the current conducted through the relay to a fan connected thereto. ### Claim 3 (depends on 1) The unitary control according to claim 1 further comprising a current transformer on the circuit board in series with the second relay and connected to the microprocessor, for generating a signal related to the current conducted through the relay to a compressor. ### Claim 4 (depends on 1) The unitary control according to claim 1, further comprising a spark sensor connected to the microprocessor for sensing arcing at the contacts of the second relay, and wherein the microprocessor is further programmed to subtract an offset from a current delay value associated with the second relay for each of a plurality of line voltage cycles; and if a signal from the spark sensor is detected, recalculate the delay value to provide for operation of the second relay using the spark sensor. ### Claim 5 (depends on 1) The unitary control according to claim 1 further comprising a spark sensor connected to the microprocessor for sensing arcing at the contacts of the second relay, the microprocessor configured to operate the second relay to reduce arcing at the contacts of the second relay without reference to input, if any, from the spark sensor. ### Claim 6 (depends on 1) The unitary control according to claim 1 wherein the processor is programmed to: delay a first actuation of the second relay by a delay time referenced from a zero crossing of the line voltage; increment the delay time by an increment; and delay a second actuation of the second relay by the incremented delay time referenced from a zero crossing of the line voltage. ### Claim 7 (depends on 6) The unitary control according to claim 6 wherein the processor is further programmed to: change the increment; increment the incremented delay time by the changed increment to obtain a changed delay time; and delay a third actuation of the second relay by the changed delay time referenced from a zero crossing of the line voltage. ### Claim 8 (depends on 7) The unitary control according to claim 7 wherein to change the increment comprises to change a delay offset to reverse a direction in which current flows through a means for switching the second relay. ### Claim 9 (depends on 1) The unitary control according to claim 1 further comprising a connector for connecting the microprocessor to a refrigerant pressure sensor. ### Claim 10 (depends on 1) The unitary control according to claim 1 further comprising a connector connecting the microprocessor to a refrigerant temperature sensor. ### Claim 11 (depends on 1) The unitary control according to claim 1 further comprising a connector for connecting the microprocessor to an outdoor temperature sensor. ### Claim 12 (depends on 1) The unitary control according to claim 1 further comprising a third relay connected to the microprocessor on the circuit board operable by the microprocessor, to connect a fan connected thereto to line voltage, and having first and second contacts at least one of which is connected to the microprocessor. ### Claim 13 (depends on 1) The unitary control according to claim 1 further comprising fourth and fifth relays, connected to the microprocessor on the circuit board and operable by the microprocessor, to connect a reversing valve connected thereto to a source of low voltage power. ### Claim 14 In combination with a climate control apparatus comprising at least a fan and a compressor, a unitary air conditioning control for operating the climate control apparatus in response to a thermostat, the unitary control comprising: a circuit board; a microprocessor on the circuit board; a first relay on the circuit board operable by the microprocessor, to connect a fan connected thereto to line voltage, and having first and second contacts at least one of which is connected to the microprocessor; a second relay on the circuit board operable by the microprocessor, to connect a compressor connected thereto to line voltage, and having first and second contacts at least one of which is connected to the microprocessor; the microprocessor configured to operate the second relay relative to the phase of the line voltage and without input as to arcing duration, if any, to reduce arcing at the contacts of the second relay. ### Claim 15 (depends on 14) The combination according to claim 14 wherein the unitary control further comprises a current transformer on the circuit board in series with the first relay and connected to the microprocessor, for generating a signal related to the current conducted through the relay to a fan connected thereto. ### Claim 16 (depends on 14) The combination according to claim 14 wherein the unitary control further comprises a current transformer on the circuit board in series with the second relay and connected to the microprocessor, for generating a signal related to the current conducted through the relay to a compressor. ### Claim 17 (depends on 14) The combination according to claim 14, further comprising a spark sensor connected to the microprocessor for sensing arcing at the contacts of the second relay, and wherein the microprocessor is further programmed to subtract an offset from a current delay value associated with the second relay for each of a plurality of line voltage cycles; and if a signal from the spark sensor is detected, recalculate the delay value to provide for operation of the second relay using the spark sensor. ### Claim 18 (depends on 14) The combination according to claim 14 further comprising a spark sensor connected to the microprocessor, for sensing arcing at the contacts of the second relay, the microprocessor configured to operate the second relay to reduce arcing at the contacts of the second relay without reference to input, if any, from the spark sensor. ### Claim 19 (depends on 14) The combination according to claim 14 wherein the processor is programmed to: delay a first actuation of the second relay by a delay time referenced from a zero crossing of the line voltage; increment the delay time by an increment; and delay a second actuation of the second relay by the incremented delay time referenced from a zero crossing of the line voltage. ### Claim 20 (depends on 19) The combination according to claim 19 wherein the processor is further programmed to: change the increment; increment the incremented delay time by the changed increment to obtain a changed delay time; and delay a third actuation of the second relay by the changed delay time referenced from a zero crossing of the line voltage. ### Claim 21 (depends on 20) The combination according to claim 20 wherein to change the increment comprises to change a delay offset to reverse a direction in which current flows through a means for switching the second relay. ### Claim 22 (depends on 14) The combination according to claim 14 wherein the unitary control further comprises a connector for connecting the microprocessor to a refrigerant pressure sensor. ### Claim 23 (depends on 14) The combination according to claim 14 wherein the unitary control further comprises a connector connecting the microprocessor to a refrigerant temperature sensor. ### Claim 24 (depends on 14) The combination according to claim 14 wherein the unitary control further comprises a connector for connecting the microprocessor to an outdoor temperature sensor. ### Claim 25 (depends on 14) The combination according to claim 14 wherein the unitary control further comprises a third relay connected to the microprocessor on the circuit board operable by the microprocessor, to connect a fan connected thereto to line voltage, and having first and second contacts at least one of which is connected to the microprocessor. ### Claim 26 (depends on 14) The combination according to claim 14 wherein the unitary control further comprises fourth and fifth relays, connected to the microprocessor on the circuit board and operable by the microprocessor, to connect a reversing valve connected thereto to a source of low voltage power. ### Claim 27 A climate control system comprising: a thermostat; a climate control apparatus comprising at least a fan and a compressor; a unitary control for operating at least the fan and the compressor of the climate control apparatus, the unitary control comprising a circuit board; a microprocessor on the circuit board; a first relay on the circuit board operable by the microprocessor, to connect a fan connected thereto to line voltage, and having first and second contacts at least one of which is connected to the microprocessor; a second relay on the circuit board operable by the microprocessor, to connect a compressor connected thereto to line voltage, and having first and second contacts at least one of which is connected to the microprocessor; the microprocessor configured to operate the second relay relative to the phase of the line voltage and without input as to arcing duration, if any, to reduce arcing at the contacts of the second relay. ### Claim 28 (depends on 27) The combination according to claim 27 wherein the unitary control further comprises a current transformer on the circuit board in series with the first relay and connected to the microprocessor, for generating a signal related to the current conducted through the relay to a fan connected thereto. ### Claim 29 (depends on 27) The combination according to claim 27 wherein the unitary control further comprises a current transformer on the circuit board in series with the second relay and connected to the microprocessor, for generating a signal related to the current conducted through the relay to a compressor. ### Claim 30 (depends on 27) The climate control system according to claim 27, further comprising a spark sensor connected to the microprocessor for sensing arcing at the contacts of the second relay, and wherein the microprocessor is further programmed to subtract an offset from a current delay value associated with the second relay for each of a plurality of line voltage cycles; and if a signal from the spark sensor is detected, recalculate the delay value to provide for operation of the second relay using the spark sensor. ### Claim 31 (depends on 30) The climate control system according to claim 30 further comprising a spark sensor connected to the microprocessor, for sensing arcing at the contacts of the second relay, the microprocessor configured to operate the second relay to reduce arcing at the contacts of the second relay without reference to input, if any, from the spark sensor. ### Claim 32 (depends on 27) The climate control system according to claim 27 wherein the processor is programmed to: delay a first actuation of the second relay by a delay time referenced from a zero crossing of the line voltage; increment the delay time by an increment; and delay a second actuation of the second relay by the incremented delay time referenced from a zero crossing of the line voltage. ### Claim 33 (depends on 32) The climate control system according to claim 32 wherein the processor is further programmed to: change the increment; increment the incremented delay time by the changed increment to obtain a changed delay time; and delay a third actuation of the second relay by the changed delay time referenced from a zero crossing of the line voltage. ### Claim 34 (depends on 33) The climate control system according to claim 33 wherein to change the increment comprises to change a delay offset to reverse a direction in which current flows through a means for switching the second relay. ### Claim 35 (depends on 27) The combination according to claim 27 wherein the unitary control further comprises a connector for connecting the microprocessor to a refrigerant pressure sensor. ### Claim 36 (depends on 27) The combination according to claim 27 wherein the unitary control further comprises a connector connecting the microprocessor to a refrigerant temperature sensor. ### Claim 37 (depends on 27) The combination according to claim 27 wherein the unitary control further comprises a connector for connecting the microprocessor to an outdoor temperature sensor. ### Claim 38 (depends on 27) The combination according to claim 27 wherein the unitary control further comprises a third relay connected to the microprocessor on the circuit board operable by the microprocessor, to connect a fan connected thereto to line voltage, and having first and second contacts at least one of which is connected to the microprocessor. ### Claim 39 (depends on 27) The combination according to claim 27 wherein the unitary control further comprises fourth and fifth relays, connected to the microprocessor on the circuit board and operable by the microprocessor, to connect a reversing valve connected thereto to a source of low voltage power.