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High-frequency control of devices internal to a hermetic compressorHigh-frequency control of devices internal to a hermetic compressor description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20080008604, High-frequency control of devices internal to a hermetic compressor. Brief Patent Description - Full Patent Description - Patent Application Claims
FIELD OF THE INVENTION [0001]The present invention relates to control of hermetic compressors, and more specifically to the high-frequency control of devices internal to a hermetic compressor. BACKGROUND OF THE INVENTION [0002]Hermetic compressors typically operate through the use of control devices, e.g., solenoids, that are located inside of the hermetic compressor housing. In order to provide main supply voltage and control signals to the devices in the housing, it is necessary to provide hermetically sealed terminals that penetrate the hermetic housing for both the main AC voltage power and the control signal wires. The controller that operates and controls the internal control devices is generally positioned outside the hermetic housing of the compressor. Internal devices of the compressor are typically interconnected to the controller by small gauge wiring. By way of example, without limitation, capacity modulation is controlled by a solenoid-actuated slide valve in some compressors. Also, an internal bleed valve may be used for pressure equalization on start-up, wherein the bleed valve is controlled by an electromagnetic solenoid actuator. At least two control wires are required to conduct the actuation control signals from the control panel to the solenoid actuator. Additional hermetic terminals are required to maintain the hermetic integrity of the housing. Such additional hermetic terminals add to the manufacturing cost of the compressor, and increase the chances that the hermetic seal may be compromised. [0003]What is needed is a convenient, inexpensive means to control the internal devices in a compressor by using the main AC power conductors. SUMMARY OF THE INVENTION [0004]The present invention is directed to a system for transmitting control signals to internal devices of a compressor. The compressor includes a housing, a sealed power terminal, and a motor for powering the compressor. The system includes a first signal converter disposed externally of the compressor housing. The first signal converter is configured to receive a control signal and convert the control signal to a modulated signal. A second signal converter is disposed internally of the compressor housing. The second signal converter is configured to decode the modulated signal. A plurality of power transmission lines is connected to an AC input power source. The plurality of power transmission lines is connected to the sealed power terminal. The first signal converter is electrically coupled to at least one of the power transmission lines to transmit the modulated signal to the second signal converter. The second signal converter is coupled to at least one power transmission line. The second signal converter is configured to receive the modulated signal and generate a driver signal in response to the modulated signal for operating at least one of the internal devices of the compressor. [0005]In another embodiment, the invention is directed to a refrigeration system. The refrigeration system includes a compressor, a condenser, and an evaporator connected in a closed refrigerant loop. The compressor has a motor to power the compressor. The compressor includes a housing and a hermetic power terminal. A frequency converter is disposed externally of the compressor housing. The frequency converter is configured to receive a control signal and convert the control signal to a high-frequency signal. A frequency decoder is disposed internally of the compressor housing. The frequency decoder is configured to decode the high-frequency signal and convert the high-frequency signal to a driver signal. A plurality of power transmission lines is connected to the hermetic power terminal. The frequency converter is electrically coupled to at least one power transmission line of the plurality of transmission lines to transmit the high-frequency signal to the frequency decoder. The frequency decoder is coupled to at least one power transmission line and configured to receive the high-frequency signal and generate a driver signal in response to the high-frequency signal for operating at least one of the internal devices of the compressor. [0006]In another embodiment, the invention is directed to a method for controlling internal devices of a hermetic compressor wherein the compressor includes a housing, a hermetic power terminal and a motor for powering the compressor. The method includes generating a control signal; converting the control signal to a high-frequency signal; transmitting the high-frequency signal on an AC input power line of the compressor; decoding the high-frequency signal; generating a driver signal in response to the decoded high-frequency signal; and controlling an internal device with the generated driver signal. [0007]An advantage of the present invention is that a dual capacity compressor may be controlled without the use of external starting devices. [0008]Another advantage of the present invention is that a modulated capacity compressor may be modulated without additional hermetic terminals. [0009]Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS [0010]FIG. 1 is a schematic diagram of a control circuit of one embodiment of the present invention. [0011]FIG. 2 is a cross-sectional view of a reciprocating hermetic compressor. [0012]FIG. 3 is an illustration of a solenoid-operated bleed valve for a pressure equalization system of a compressor. [0013]FIG. 4 is a diagram of a refrigeration system. DETAILED DESCRIPTION OF THE INVENTION [0014]The description of the high-frequency compressor control system will be given by reference to the accompanying illustrations and drawings provided as FIGS. 1 & 2. It is contemplated that the high-frequency compressor control system may be a component of a climate control system, including a refrigeration, freezer or HVAC system, however its use is not limited to such systems as the high-frequency control system may be used in any system utilizing a compressor. [0015]An exemplary embodiment of the high-frequency compressor control system is generally designated as reference number 10. A capacity or solenoid start signal S is input to a frequency converter 12. The signal S is a predetermined control voltage, preferably in the range of 24 VAC to 230 VAC. The signal S may be generated by an automatic or manually-operated controller. The input AC power line 16 is preferably single-phase AC power, but the invention may also be employed on three-phase and other multi-phase AC- and DC-input power lines. The output 14 of the frequency converter 12 may be connected to a single-phase input AC power line across a power conductor and a neutral conductor, or across two power conductors. Alternately the output 14 of the frequency converter 12 may be connected between two phases of a three-phase input AC power line 16. Finally, the frequency converter 12 may be connected to any one of the power terminal inputs and a conductor connected to the compressor housing. In addition, if required, additional lugs for grounding and neutral connections may also be provided. The various arrangements described here for connecting the frequency converter to the input conductors are examples and the invention is not limited thereto. Those skilled in the art will appreciate that other coupling arrangement for connecting the frequency converter 12 may be employed within the spirit and scope of the present invention. [0016]The input AC power line 16 is connected to a hermetic power terminal 18 mounted on the compressor hermetic housing 20. The hermetic power terminal 18 provides a sealed connection through the hermetic compressor housing 20. The hermetic power terminal 18 includes connecting lugs 18a, 18b & 18c for connecting the input AC power line 16. Each AC line 18a & 18b may also be used with the start lead (18c) connected as a common conductor to connect the frequency converter 12. Other sealed connections for penetrating the hermetic housing 20 may also be employed, such as by way of example and not limitation, airtight packing glands or conduit connectors capable of maintaining an airtight seal when exposed to the internal pressures generated by the compressor. [0017]In an alternate configuration, lines 18a to 18c or 18b to 18c may be used as a single input connection for the frequency converter 12. This configuration would apply the same for a three-phase input AC power line. The input AC power line 16 is connected to a compressor motor 22 through the hermetic power terminal 18. The motor 22 has motor leads 24 connected to the hermetic power terminal 18 from the interior of the housing 20. [0018]In an alternate embodiment, the motor 22 may be powered by the output of a variable speed drive (VSD) 114 disposed between the input AC power line. (See, e.g., FIG. 4). In some cases, the frequency of the input AC power line 16 may be varied by the VSD, e.g., below 30 Hz, or greater than 90 Hz. If no VSD is used, the control panel 108 is powered directly by the input AC power line 16, in series with the motor 22. [0019]The compressor 34 has an internal solenoid valve 26 for modulating the capacity of the compressor. A frequency decoder/driver 28 is connected to an electromagnetic coil 30 in the solenoid valve 26. When the electromagnetic coil 30 of the normally closed solenoid valve 26 is energized, the valve 26 is opened to modulate the capacity of the compressor. Continue reading about High-frequency control of devices internal to a hermetic compressor... Full patent description for High-frequency control of devices internal to a hermetic compressor Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this High-frequency control of devices internal to a hermetic compressor patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like High-frequency control of devices internal to a hermetic compressor or other areas of interest. ### Previous Patent Application: Hermetric refrigerant compressor Next Patent Application: Transfer pump with several pistons Industry Class: Pumps ### FreshPatents.com Support Thank you for viewing the High-frequency control of devices internal to a hermetic compressor patent info. 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