Methods and apparatus for providing motor control signals
View Patent ↗A method for providing a compatible interface between a motor control circuit and a system controller is described. The method includes determining which signals in the interface have incompatible voltage requirements, and inserting a series resistance in an interface extending between the motor control circuit and the system controller for each signal determined to have incompatible voltage requirements therebetween.
1. A passive interface for utilization between a system controller and a variable speed motor (VSM) controller for an electronically controlled VSM, said passive interface comprising:
a first plurality of conductors, each conductor in said first plurality of conductors configured to directly connect an output of the system controller to a corresponding input of the VSM controller, said first plurality of conductors configured to provide an operating power to the VSM controller; and
a second plurality of conductors, each conductor in said second plurality of conductors separately connecting a signal output of the system controller to a respective input of the VSM controller, each conductor in said second plurality of conductors comprising a series resistor therein for passively reducing a voltage level of signals originating at the system controller, each series resistor comprising an electrical resistance that corresponds to a predefined voltage level of the respective input of the VSM controller.
2. A passive interface according to claim 1 wherein at least one of said series resistors comprises a resistance value capable of interfacing a nominal 115 VAC signal from the system controller to a nominal 24 VAC level at the VSM controller.
3. A passive interface according to claim 1 wherein at least one of said series resistors comprises a resistance value capable of interfacing a nominal 230 VAC signal from the system controller to a nominal 24 VAC level at the VSM controller.
4. A passive interface according to claim 1 wherein at least one of said series resistors comprises a resistance value to interface a signal originating from the system controller to a corresponding motor tap signal input at the VSM controller.
5. A passive interface according to claim 1 wherein said second plurality of conductors comprises one or more of a wiring harness including said resistors, a separate circuit board assembly incorporated into said interface onto which said resistors are mounted, said resistors installed between a wiring harness and the VSM controller, and said resistors installed between a wiring harness and the system controller.
6. A passive interface according to claim 1 wherein said second plurality of conductors comprises a return line extending between the system controller and the motor control circuit, wherein one of said resistors is configured to provide a series resistance in said return line.
7. A passive interface according to claim 1 wherein said second plurality of conductors is positioned external to the system controller and the VSM controller.
8. A system for controlling an electronically controlled variable speed motor (VSM) including a motor controller, said system comprising:
a system controller; and
a passive interface electrically coupling said system controller to the motor controller, said passive interface comprising:
a first plurality of conductors each configured to directly connect an output of said system controller to a corresponding input of the motor controller, said first plurality of conductors configured to provide an operating voltage to the motor controller; and
a second plurality of conductors each comprising a series resistor therein for passively reducing a voltage level of signals originating at said system controller, each of said second plurality of conductors configured to connect a signal output of said system controller to a respective input of the motor controller, each series resistor comprising an electrical resistance that corresponds to a predefined voltage level of the respective input of the motor controller.
9. A system according to claim 8 wherein at least one of said series resistors comprises a resistance value capable of interfacing a nominal 115 VAC signal from said system controller to a nominal 24 VAC level at the motor controller.
10. A system according to claim 8 wherein at least one of said series resistors comprises a resistance value capable of interfacing a nominal 230 VAC signal from said system controller to a nominal 24 VAC level at the motor controller.
11. A system according to claim 8 wherein at least one of said series resistors comprises a resistance value to interface a signal originating from said system controller to a corresponding motor tap signal input at the motor controller.
12. A system according to claim 8 wherein said second plurality of conductors and the corresponding series resistors comprise:
a resistor having a resistance value to interface a HEAT signal originating from said system controller to a corresponding motor tap signal input at the motor controller;
a resistor having a resistance value to interface a COOL signal originating from said system controller to a corresponding motor tap signal input at the motor controller; and
a resistor having a resistance value to interface a FAN signal originating from said system controller to a corresponding motor tap signal input at the motor controller.
13. A system according to claim 8 wherein second plurality of conductors and the corresponding series resistors comprise:
at least one nominal 10 Kohm, two Watt resistor for reducing a nominal 115 VAC signal from said system controller to a nominal 24 VAC level at the motor controller; and
at least one nominal 22 Kohm, five Watt resistor for reducing a nominal 230 VAC signal originating from said system controller to a nominal 24 VAC level at the motor controller.
14. A system according to claim 8 wherein said second plurality of conductors comprises one or more of a wiring harness including said resistors, a separate circuit board assembly incorporated into said interface onto which said resistors are mounted, said resistors installed between a wiring harness of said interface and the motor controller, and said resistors installed between a wiring harness of said interface and said system controller.
15. A system according to claim 8 wherein said second plurality of conductors comprises a return line extending between said system controller and the motor controller, one of said resistors configured to provide a series resistance in said return line.
16. A system according to claim 8 wherein said passive interface is positioned external to said system controller and the motor controller.