Abstract:
An integrated module encased in protective housing is electrically and mechanically connected to a solenoid, which remotely actuates an Automatic Transfer Switch (ATS) or lighting contactor. The module includes a full-wave bridge rectifier, voltage transient voltage protection-circuitry, a proximity detector to determine the solenoid&#39;s plunger position, and a mounting strap to attach the solenoid to a frame. In addition, the module accepts various resistor values as plug-in devices to reduce a line voltage and incorporates a communication device/modem for connection to the Internet. The module allows a fixed voltage across the solenoid coil, and permits the solenoid to be connected to various operating voltages.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to actuators, and more particularly to a solenoid assembly that remotely actuates a mechanical device. 
     A solenoid is an electromagnet including a coil wrapped around a plunger. A solenoid converts electrical energy into mechanical energy. A magnetic field is generated by the flow of current through the coil. When current flows through the coil, a magnetic field is generated that moves a plunger inserted in the coil. Magnetism produced by the coil draws the plunger into the coil. Alternating current has positive and negative peak amplitudes. When alternating current is applied to a solenoid, the magnetic field produced is strongest at the positive and negative peaks of the sinusoidal signal. Solenoid force increases with an increase in coil current because as current increases, magnetism builds in the solenoid coil. When magnetism builds up in the coil, the plunger is moved within the coil. 
     Known solenoids include accessory packages which incorporate mechanical switches. These accessory packages are used for holding the solenoid in an actuated condition at reduced power consumption. In certain known configurations, the winding is tapped to provide a coil of reduced force and connected via a switch actuated by the plunger. Other known configurations include a solenoid mechanically strapped to a device electrically connected via long leads to a separate rectifier. 
     Solenoids are used in a wide variety of electrical applications requiring linear movement. Typical electrical applications range from household appliances, including washing machines and dishwashers, to automobiles and doorbell chimes. One known use of solenoids has been to operate Automatic Transfer Switches (ATS), which are primarily used in backup power systems. ATSs transfer an electrical load connected to one power source, e.g., a public utility, to an alternative power source in case of a power failure with the public utility. 
     Typically, solenoids are mounted to a frame with a strap or a plate, which after multiple connects and disconnects cause the strap to become crinkled and worn. In addition, known solenoids only operate at a specific voltage. Therefore, multiple solenoids rated at various voltages are required to cover a voltage range. 
     It would be desirable to have a solenoid electrically connected to an accessory package, e.g., a module, with an attachment to mount the solenoid to a frame. Further, it would bc desirable if the module provided transient voltage protection. Also, it would be desirable if the module enabled the solenoid to operate at various voltages. Lastly, it would be desirable if the module interfaced to the Internet to communicate solenoid status or accept activation commands. 
     BRIEF SUMMARY OF THE INVENTION 
     In an exemplary embodiment, a solenoid assembly includes an integrated module, including a rectifier, electrically and physically connected to a solenoid. The solenoid assembly remotely actuates an Automatic Transfer Switch (ATS). The module includes a full-wave bridge rectifier, voltage transient protection components, a resistor module, a Hall effect device, and a communication interface. In addition, the module is mechanically coupled to an attachment to fasten the solenoid assembly to a frame. Further, the module interfaces with a microprocessor. The wiring electrically connecting the rectifier to the solenoid is placed within a housing enclosing the module. This housing serves to protect the electrical components from human touch. 
     In an exemplary embodiment of the invention, the module includes a full-wave bridge rectifier electrically connected to alternating voltage. The full-wave bridge rectifier is electrically connected to the voltage transient protection components, and the resistor module. The resistor module accepts various values of resistors and is electrically connected in series to the solenoid. The solenoid includes a plunger. The plunger is connected to the Automatic Transfer Switch. The Hall effect device is in proximity to the solenoid&#39;s plunger extension. The Hall effect device senses and conveys the position of the solenoid&#39;s plunger. The communication interface is connected to the Internet from which the module receives remote commands and transmits status of the solenoid. 
     In an exemplary embodiment, the full-wave bridge rectifier includes a plurality of diodes. Alternating voltage is input to the full-wave bridge rectifier which converts alternating voltage to direct voltage. Transient voltage protection for the full-wave bridge rectifier and other devices, e.g., Hall effect device and communications interface, is provided. 
     The full-wave bridge rectifier and transient voltage protection circuitry are electrically connected to a resistor module. The resistor module is electrically connected in series with the solenoid and affects the voltage delivered to the solenoid windings. By varying the resistance value of resistors, the resistor module enables the solenoid to electrically connect to various voltages, e.g., 120V, 208V, 240V, 277V, and 480V. This allows, the voltage across the solenoid coil to be of a set voltage, e.g., 120V, and the selected resistor to accommodate a line voltage. 
     The Hall effect device senses the plunger&#39;s position. The microprocessor, interfacing with the module, executes a program to store the plunger position and the solenoid activation state. The plunger&#39;s position is stored in memory when a microprocessor executes the program. In addition, the plunger&#39;s position is transferred across the Internet when the communications interface receives a command from the Internet. 
     The above described solenoid assembly is a cost-effective and reliable and provides transient voltage protection, enables a solenoid to operate at various voltages, accept remote commands and report a status over the Internet, and allows the solenoid to be attached to a frame. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram of a known Automatic Transfer Switch; 
         FIG. 2  is an illustration of a solenoid with an integrated mounted rectifier and mounting strap; 
         FIG. 3  is a schematic of an exemplary embodiment of a rectifier circuit; 
         FIG. 4  is a schematic of an exemplary embodiment of a rectifier circuit using silicon controller rectifiers; and 
         FIG. 5  is a block diagram of a module connected to the Internet. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  illustrates a known Automatic Transfer Switch (ATS)  10  for switching electric power among a plurality of power sources. ATS  10  is electrically connected to a power source  12 , a power source  14  and a load  16 . Power source  12  typically is a public electric utility that supplies electrical power to load  16 , such as a hospital, an airport radar tower, or other continuous electrical power user. If, for example, power source  12  fails or becomes inadequate to supply the electrical power required by load  16 , ATS  10  transfers the source of electrical power from power source  12  to power source  14 . In one embodiment, power source  14  is a generator set. ATS  10  monitors the condition of power source  12 . When the voltage generated by power source  12  is restored to a predetermined level, ATS  10  transfers load  16  from power source  14  back to power source  12 . The foregoing description of ATS  10  operation is exemplary only, and additional functions may be performed by automatic transfer switches such as ATS  10 . 
     ATS  10  includes a mechanical drive assembly (not shown). The mechanical drive assembly is connected to a moveable contact assembly  18 , which is connected either to power source  12  or power source  14 . A solenoid  20  is mechanically connected to the mechanical drive assembly. By energizing solenoid  20 , ATS  10  is able to transfer power from power source  12  to power source  14 . In an alternative embodiment, solenoid  20  is mechanically connected to actuate a multi-pole contactor (not shown). 
       FIG. 2  illustrates a solenoid assembly  18  including a solenoid  20  electrically and mechanically connected to a module  22 , an attachment  24 , and a mounting surface  25 . Attachment  24  includes openings  26  and  28  to mount solenoid  20  to a frame of ATS  10  (not shown). Attachment  24  includes a concave mounting device  25  that couples to solenoid  20 . In one embodiment, attachment  24  is integrally molded with mounting device  25  and module  22 . In an alternative embodiment, mounting device  25  is integrally coupled to module  22 . In a further alternative embodiment, attachment  24  is a flange including an opening coupled to module  22  and mounting device  25 . In a further alternative embodiment, solenoid  20 , module  22 , mounting device  25 , and attachment  24  are configured as a single unit. Attachment  24  coupled with mounting device  25  is configured to mount solenoid  20  and module  22  to a frame of ATS  10  (not shown). In an alternative embodiment, attachment  24  and mounting device  25  are configured to mount solenoid  20  to a frame of ATS  10  (not shown). 
     Module  22  is a housing for an electrical circuit (not shown in  FIG. 2 ) described below. Module  22 , attachment  24  and mounting device  25  are water resistant and fabricated from plastic. In an alternative embodiment, module  22 , attachment  24  and mounting device  25  are fabricated from metal, which serves to electrically ground a rectifier circuit (shown in FIG.  3  and FIG.  4 ). In a further embodiment, module  22  is fabricated from plastic, and attachment  24 , mounting device  25  are fabricated from metal. In a still further embodiment, module  22  is fabricated from metal, and attachment  24  and mounting device  25  are fabricated from a plastic. Furthermore, module  22  includes terminals  30  and  32  which are electrically connected to alternating voltage to power the rectifier circuit (not shown in FIG.  2 ). 
       FIG. 3  is a schematic of an exemplary embodiment of an electric circuit  40  housed in module  22  (shown in FIG.  2 ). Electric circuit  40  comprises a full-wave bridge rectifier  42  electrically connected to transient voltage protection circuitry  44  at nodes  46  and  48 . Transient voltage protection circuitry  44  is electrically connected to resistor module  50  at node  46 . Resistor module  50  is connected in series with solenoid  20  (shown in  FIG. 2 ) at node  52 . Hall effect device  54  is located in the proximity of  20 . Solenoid  20  is connected to ATS  10  (shown in  FIG. 1 ) via plunger  58 . In one embodiment full-wave bridge rectifier  42  includes diodes  60 ,  62 ,  64  and  66 . Full-wave bridge rectifier  42  is connected to a voltage source  68  at nodes  70  and  72 . 
     In one embodiment, transient voltage protection circuitry  44  is connected to nodes  46  and  48 , after full-wave bridge rectifier  42 , to protect the windings and electronics of solenoid  20 . In an alternative embodiment, transient voltage protection circuitry  44  is connected to nodes  70  and  72 , before full-wave bridge rectifier  42 , to protect diodes  60 ,  62 ,  64 , and  66 . In one embodiment, transient voltage protection circuitry  44  includes a common mode choke circuit. In another embodiment, transient voltage protection circuitry  44  includes a free-wheeling diode. In a further alternative embodiment, transient voltage protection circuitry  44  includes metal oxide varistors (MOVs). 
     Resistor module  50  includes a plug-in resistor  74 . Plug-in resistor  74  reduces the voltage to solenoid  20 . By selecting various resistor values for plug-in resistor  74 , solenoid  20  can be electrically connected to various operating voltages, e.g., 120V, 208V, 240V, 277V, and 480V. In addition, resistor module  50  protects the windings of solenoid  20  by “opening” the electric circuit in the event solenoid  20  is energized and its plunger  58  is unable to move. In one embodiment, resistor module  50  is connected in series after the full-wave bridge rectifier  42  at nodes  46  and  52 . In another embodiment, resistor module  50  is electrically connected in series before full-wave bridge rectifier  42  between voltage source  68  and node  70 . In yet another embodiment, resistor  74  is hard-wired in electric circuit  40 . 
     Hall effect device  54  is located in proximity to solenoid  20  to detect an extension of solenoid plunger  58 . In one embodiment, Hall effect device  54  is connected to an external controller (not shown) via signal out  76  to indicate plunger&#39;s  58  position. In an alternative embodiment, Hall effect device  54  is connected to a microprocessor (shown in FIG.  5 ). In a further alternative embodiment, a limit switch is electrically connected to solenoid  20  to determine plunger&#39;s  58  position. 
     In one embodiment, solenoid assembly  18  (shown in  FIG. 2 ) is connected to ATS  10  (shown in FIG.  1 ). The plunger  58  of solenoid  20  (shown in  FIG. 2 ) is mechanically coupled to a mechanical drive assembly (not shown) of ATS  10 . The mechanical drive assembly is connected to a moveable contact assembly (not shown), which is connected to a power source  12  (shown in FIG.  1 ), e.g., electric utility power source, or power source  14  (shown in FIG.  1 ), e.g., a generator set. By energizing solenoid  20 , ATS  10  transfers power from power source  12  to power source  14 . In an alternative embodiment, solenoid  20  is mechanically connected to actuate a multi-pole contactor (not shown). In a further alternative embodiment, solenoid assembly  18  is used in alternating current applications. 
       FIG. 4  is a schematic of an exemplary embodiment of an electric circuit  80  housed in module  22 . Components of electric circuit  80 , identical to the components of electric circuit  40  (shown in FIG.  3 ), are identified in  FIG. 4  using the same reference numerals as used in FIG.  3 . Electric circuit  80  comprises a full-wave bridge rectifier  42  electrically connected to transient voltage protection circuitry  44  at nodes  46  and  48 . Transient voltage protection circuitry  44  is electrically connected to resistor module  50  at node  46 . Resistor module  50  is connected in series with solenoid  20  (shown in  FIG. 2 ) at node  52 . Hall effect device  54  is located in proximity to solenoid  20 . Solenoid  20  is connected to ATS  10  (shown in  FIG. 1 ) via plunger  58 . Full wave bridge-rectifier  42  includes silicon controlled rectifiers (SCRs)  82  and  84  and diodes  62  and  64 . In one embodiment, SCRs&#39;  82  and  84  gates  86  and  88  are electrically connected to an external controller (not shown) to control turning full-wave bridge rectifier  42  “on” and “off”. Full-wave bridge rectifier  42  is connected to a voltage source  68  at nodes  70  and  72 . 
       FIG. 5  is a block diagram of module  22  (shown in  FIG. 2 ) connected to solenoid  20  (shown in FIG.  2 ). Module  22  includes a communication device  90  electrically connected to the Internet  92 . Module  22  is also electrically connected to microprocessor  94 . Microprocessor  94  interfaces with program  96  and is electrically connected to Hall effect device  54  (shown in FIG.  3  and FIG.  4 ), memory  98  and communications device  90 . 
     The term microprocessor, as used herein, refers to microcontrollers, CPUs, reduced instruction set circuits (RISC), application specific integrated controllers (ASICs), logic circuits, and any other circuit or processor capable of interfacing with memory and executing a series of instructions or software programs. In one embodiment, memory  98  is volatile Random Access Memory (RAM). In an alternative embodiment, memory  98  is nonvolatile memory (NVRAM). In a further alternative embodiment, memory  98  is Programmable Read-Only memory (PROM). In a still further alternative embodiment, memory  98  is Electrically Eraseable Programmable Read-Only Memory (EEPROM). 
     In an exemplary embodiment, communications device  90  is a modem connected to the Internet  92 . In an alternative embodiment, communications device  90  is connected to a dedicated phone-link (not shown). In a further alternative embodiment, communications device  90  is connected to a dedicated T1 line. In a still further alternative embodiment, communications device  90  is connected to a Digital Subscriber Line (DSL). In another embodiment, communications device  90  is connected to an Integrated Services Digital Network (ISDN). In yet another embodiment, communications device  90  is connected to a communications cable. In yet another embodiment, wireless technologies are used to facilitate connection to communications device  90 . In an additional embodiment, communications device  90  is connected to an intranet. In yet an additional embodiment, communications device  90  is connected to satellite technologies. 
     In the exemplary embodiment, module  22  responds to commands sent from a remote location to actuate electrical switching functions. Communications device  90  receives commands from the Internet  92 . In one embodiment, the commands request plunger&#39;s  58  (shown in FIG.  3  and  FIG. 4 ) position. In another embodiment, the commands request to actuate solenoid  20 . In yet another embodiment, the commands request solenoid&#39;s  20  status. Communication device  90  transmits the information requested over the Internet  92 . 
     In one embodiment, microprocessor  94 , memory  98 , and program  96  are included in an external controller (not shown) electrically connected to module  22 . In one embodiment, program  96  is executed by microprocessor  94 . Program  96  commands microprocessor  94  to have module  22  determine a plunger  58  (shown in FIG.  3  and  FIG. 4 ) position of solenoid  20  and store the information in memory  98 . Program  96  also commands microprocessor  94  determine if solenoid  20  has been actuated and store the information in memory  98 . In an alternative embodiment, microprocessor  94 , memory  98 , program  96 , are contained within the housing of module  22 . 
     The methods and apparatus as described here in are not limited to actuating Automatic Transfer Switches by using a solenoid. Another example of a system that can be actuated by using a solenoid is a lighting contactor. A further example of a system that can be actuated using a solenoid is an emergency bus to conserve power. 
     While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.