POWER DISTRIBUTION CONTROL SYSTEM DESCRIPTION TECHNICAL FIELD This invention relates generally to the distribution and control of electrical power for equipment used in vehicles both on land and sea, and more specifically to an improved apparatus for the control and electrical power distribution for such equipment. BACKGROUND ART
The basic wiring methodology for the distribution of electrical power in vehicles is the same today as it was seventy- five years ago. A single distribution point typically feeds all electrical equipment through a large and cumbersome wiring harness. Drawbacks to this traditional method of electrical power distribution include, but are not limited to, the following:
Configuration changes and flexibility in design are difficult and expensive, if not prohibitive, for the original equipment manufacturer (OEM) ;
Installation is time consuming and complex as all circuits must run wiring "home" to the central distribution point;
Troubleshooting a problem is very difficult as a short circuit or improperly wired circuit could be located anywhere within the wiring harness;
Often the wiring harness has been built in behind cabinetry or other structures, and access is limited and is thus extremely time consuming; There is no feedback (other than a blown fuse or tripped circuit breaker) to the user indicating proper functioning of a circuit, or whether there is an electrical fault in the system;
There is no enable circuitry, which restricts a circuit from being activated unless specified conditions are first met; and
Multiple points of switch control, with circuit status available on all points of the switch control is,
if even possible, extremely expensive and complex to install .
DISCLOSURE OF INVENTION
The power distribution control system of this invention is designed to control distributed power in vehicles both on land and at sea. The inventive system incorporates many unique design features heretofore unavailable in electrical power distribution. A typical embodiment of the inventive design involves the distribution of power in large 12 volt D.C. commercial vehicles with complex auxiliary lighting and hydraulic control systems. The inventive system is capable of direct current (DC) and alternating current (AC) power distribution . The inventive power distribution control system is fully multiplexed - all components whether switch panels or power distribution centers (PDCs) are linked by a common bus and share all communication. For example, an activated switch on one panel is enunciated (via light or sound) on all other switch panels containing the same switch function. Power-output problems (e.g., short circuits, blown breakers, stuck relays, etc.) are likewise indicated at all switch panel positions relating to that output. A switch on any panel can activate multiple outputs in multiple PDCs.
Further design features include multiple power distribution centers; multiple switch panels; multiple enable circuits; RF interface; 50-90 percent reduction in installation time; corrosion resistance/immersibility; fault indicator feedback; choice of communication mediums (e.g., twisted pair, fiber optics, existing power grid); and field configurable.
A typical embodiment of the invention is a power control system for use in 12 and 24 volt vehicles. The operator controls each output via one or more remote keypads, with feedback of output status. A radio (wireless) keypad may also be used, with (or without) feedback.
Such a system may consist of, but is not limited to, the following components: up to four power distribution controllers; up to two hydraulic power controllers; up to four wired keypads; up to two wireless keypads; one RF receiver (to support wireless keypads) ; and one chassis signal interface.
Each unit communicates with the others in a network via twisted pair, fiber optics, or the existing power grid. Each button on each keypad in use may be assigned to any output. All outputs may be programmed as momentary or maintained. These parameters can be pre-programmed before operation, with re-programming in-circuit possible, using non-volatile data storage. Any combination of keys on any one keypad are allowed. Separate versions may be provided for 12 and 24 volt systems, as well as 110/220 volt systems .
The inventive system may also provide automatic configuration of a replacement switch panel or PDC . The system will detect the replacement of a component and can automatically configure that component to the "map" of the fixture it replaced. Field service or replacement is thus reduced to simply swapping components and activating the system.
The system can also be easily expanded. The most basic level of the system is one switch panel and one PDC.
Expansion is facilitated by simply plugging in additional switch panels or PDCs as requirements grow. BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a schematic diagram of a conventional wiring system for a typical prior art specialty vehicle incorporating traditional wiring methodology with wiring harnesses leading from fixtures and switch panels "home" to a central point of distribution;
Fig. 2 is a schematic diagram of a first embodiment of the present invention utilizing multiple switch panels and two power distribution centers (PDCs), one for electrical power control and one for hydraulic control;
Fig. 3 is a schematic diagram of a second embodiment
of the present invention utilizing multiple switch panels and fully network distributed power through the use of four power distribution centers (PDCs), three for electrical power control and one for hydraulic control; Fig. 4 is a schematic diagram of the inputs and outputs of a six-circuit modular power distribution center (PDC) of this invention;
Fig. 5 is a schematic diagram of a typical six to twelve position keypad of this invention; and Fig. 6 is a schematic diagram illustrating the inputs and outputs of a typical logic control unit utilized in a "spoke and hub" network control system of this invention. BEST MODE FOR CARRYING OUT THE INVENTION
Fig. 1 is a schematic diagram of a conventional wiring system for a typical prior art specialty vehicle (such as a tow truck) incorporating traditional wiring methodology with wiring harnesses leading from fixtures and switch panels "home" to a central point of distribution. Vehicle 10 includes three switch panels 12 connected in traditional fashion through wiring harness (es) 14 to control marker lights 16, reverse lights 18, tool box lights 20, driver side light 22, passenger side light 24, left turn lights 26, right turn lights 28, brake lights 30, beacons 32, strobes 34, work up 36, and work down 38. Hydraulic power distribution center 40 is connected to hydraulic controls 42 by harness 44. In this prior art installation, there are twenty-three wires between the cab and body, ten wires between the pylon and tool box, seventeen wires between each tool box, and fifty-eight total wires in the right tool box.
Fig. 2 is a schematic diagram of a first embodiment of the present invention utilizing multiple switch panels and two power distribution centers (PDCs), one for electrical power control and one for hydraulic control. Here, vehicle 10 includes three switch panels 46 connected in network fashion through network cable 48 to electric power distribution center 50 to control the marker lights 16, reverse lights 18, tool box lights 20, driver side
light 22, passenger side light 24, left turn lights 26, right turn lights 28, brake lights 30, beacons 32, strobes 34, work up 36, and work down 38. Hydraulic power distribution center 52 is connected to hydraulic controls 54 by harness 56. In this inventive installation, there is a dramatic reduction in wiring both between and internal to each of the components of the vehicle; there are only six wires between the cab and body, still ten wires between the pylon and tool box, only eight wires between each tool box, and only thirty- two total wires in the right tool box.
This first embodiment may be specifically configured as follows: an eighteen channel DC power controller for use in 12 and 24 volt vehicles, capable of driving up to 20 Amp inductive or 30 Amp resistive loads (at 12 V) . Each output uses plug-in relays and fuses or resetable circuit breakers.
1. Inputs
Power input: One 3/8" stud on bus bar for battery, and one #10-32 stud for ground. Power input should be able to survive reversed battery polarity and 80 volt surges without damage.
Data in/out to network: Four conductor RJ- 11 connector, carrying differential serial data, DC power, and common. Data input/output should be able to survive miss-wired/shorted data cables.
Network Data: The enable signals on the chassis control interface (relayed via network) are used as enables for all outputs. Each output may be programmed to require one, two, or all three enable signals to be met. The chassis interface controller normally sends five signals to five output channels dedicated on the first power distribution controller. However, those output channels may be configured for other use. 2. Outputs
Power Out: Eighteen normally open (N.O.) outputs, each with #10-32 studs. If space is available, provide each with a 1/4" quick connector for normally
closed (N.C.) output, and a yellow LED. A green LED indicates the state of each output. A red LED indicates open fuse/breaker with relay closed. Each output may be configured as either a momentary or a latching ON function. Each output may be configured to stay off unless one, two, or all three enable conditions have been met. Each output uses a plug-in relay and a plug-in style fuse/circuit breaker.
3. Indicators Eighteen green LEDs indicate the state of each N.O. output; eighteen red LEDs indicate open fuse/breaker with relay closed; eighteen yellow LEDs indicate power at N.C. relay contact closed; and one green LED indicates control power. 4. Operating voltage range
11.0 to 15.0 volts for normal operation, graceful shutdown on low voltage (22 to 30 volts on 24 volt systems) . Unit should be able to survive 80 volt surges to all battery and load terminals without damage. 5. EMI compatibility
Unit should not fail to operate reliably in RF fields typical of vehicle mounted 100 watt radio transmitters in the range of 1 to 900 MHz.
6. Data communications Data communications should be supervised to detect and reject errors. Upon loss of communications, the outputs should go OFF, and the indicators show fault status .
7. Startup and crash security Startup of the processor should be assured under all conditions. A watch-dog timer should be ready to catch any foreseeable crash and gracefully reset the processor. Upon power-up, each processor shall test its memories for consistency with previously stored data. Failures may require various responses.
8. Physical
Printed circuit board is doublesided fiberglass with 3 oz . copper, plated-thru holes, red
solder mask, and legend. A conformal coating is desired, at least over the logic circuitry. The size may be approximately 10" x 14". It is mounted in a polycarbonate or steel cabinet. Operating temperature range is preferably from -40 to 85 degrees C (-40 to 185 degrees F) .
The use of "plug and play" connectors may be incorporated as an option to the network systems. An internal harness in the PDC connects to an exterior harness through the use of a Packard or similar waterproof connector. Installation time or replacement is thus reduced to a simple and efficient process, whether in the field or during manufacture.
Fig. 3 is a schematic diagram of a second embodiment of the present invention utilizing multiple switch panels and fully network distributed power through the use of four power distribution centers (PDCs), three for electrical power control and one for hydraulic control. Here, vehicle 10 includes four switch panels 60 connected in network fashion through network cable 62 to electric power distribution centers 64 to control the marker lights 16, reverse lights 18, tool box lights 20, driver side light 22, passenger side light 24, left turn lights 26, right turn lights 28, brake lights 30, beacons 32, strobes 34, work up 36, and work down 38. Hydraulic power distribution center 66 is connected to hydraulic controls 68 by harness 70. In this installation of the second embodiment of the invention, there is a further dramatic reduction in wiring both between and internal to each of the components of the vehicle; there is now only one wire between the cab and body, only two wires between the pylon and tool box, and only three wires between each tool box, and only thirty-two total wires in the right tool box.
This second embodiment may be specifically configured as follows: a six or ten channel DC power controller for use in 12 and 24 volt vehicles, capable of driving up to 20 Amp inductive or 30 Amp resistive loads (at 12 V) . Each output uses plug-in relays and fuses.
1 . Inputs
Power input: One #10-32 stud on a bus bar for battery, and one #10-32 stud for ground. Power input should be able to survive reversed battery polarity and 80 volt surges without damage.
Data in/out to network: One four conductor connector, carrying differential serial data, DC power, and common. Data input/output should be able to survive miss-wired/shorted data cables. Network Data: The enable signals on the
PDC (and others relayed via network) are used as an enable for all outputs. Each output may be programmed to require any combination of enable signals. Each output may be assigned to one or more keypad buttons. Enable signals: Up to 16 (4 inverted, 12 normal) 12 (24) volt DC signals to sixteen 1/4" tabs. A green LED indicates state of each enable. Pull-up/pulldown resistors may be used as required.
2. Outputs Switches Power Out: Six or ten N.O. outputs, each with #10-32 studs, if space is available. A green LED indicates the state of each output. A flashing green LED indicates open fuse/breaker with relay closed. Each output has an override slide switch. Each output may be configured as either a momentary or a latching ON function. Each output may be configured to stay off unless the AND of any combination of enable signals (from enable inputs on this or any other PDC) is TRUE. Each output uses a plug-in relay and a plug in fuse/circuit- breaker.
Alert Output: An alert output will provide a flashing DC signal corresponding to the PTO signal. This output shall be rated to supply 100 mA to an external beeper, Sonalert, or relay. PTO signal comes from an enable input on this or another PDC, assigned at time of manufacture .
3. Indicators
Six to ten green LEDs indicate the state of
each N.O. output; one green LED indicates control power; one red LED indicates state of network connections; and up to sixteen green LEDs indicate states of enable signals.
4. Operating voltage range 6.0 to 15.0 volts for normal operation, graceful shutdown on low voltage (12 to 30 volts for 24 volt systems) .
5. EMI compatibility
Unit should not fail to operate reliably in RF fields typical of vehicle mounted 100 watt radio transmitters in the range of 1 to 900 MHz.
6. Data communications
Data communications should be supervised to detect and reject errors. Upon loss of communications, the outputs should go OFF, and the indicators show fault status .
7. Startup and crash security
Startup of the processor should be assured under all conditions. A watch-dog timer should be ready to catch any foreseeable crash and gracefully rest the processor. Upon power-up, each processor shall test its memories for consistency with previously stored data. Failures may require various responses.
8. Physical Printed circuit board is doublesided fiberglass with 3 oz . copper, plated- thru holes, red solder mask, and legend. A conformal coating is desired, at least over the logic circuitry. The size may be approximately 8" x 8". It is mounted in a polycarbonate or metal cabinet. Operating temperature range -40 to 85 degrees C (-40 to 185 degrees F) .
Fig. 4 is a schematic diagram of the inputs and outputs of a six-circuit modular power distribution center (PDC) 80 of this invention. PDC 80 may include power supply 82, RS-485 transceiver 84, through which communication lines 86 are directed, and microprocessor 88, such as an AT89C2051 (ATMEL) . Microprocessor 88 includes, processes, and controls general purpose inputs
90, status indicators 92, relays 94 (e.g., for power take off, beacon, flash, work up, work down, and auxiliary), feedback 96, and output status 98, in a manner well known in the art. This PDC can be used stand alone or as part of a multiple PDC system. Output wires can be run directly to a printed circuit board in the PDC or attached through the use of a waterproof connector and internal harness .
Fig. 5 is a schematic diagram of a typical six to twelve position keypad 100 of this invention. Keypad 100 may include power supply 102, RS-485 transceiver 104, through which communication lines 86 are directed, and microprocessor 108, such as an AT89C2051 (ATMEL) . Microprocessor 108 includes, processes, and controls a plurality of switches 110 and a plurality of status indicators 112. In a typical tow truck installation, switches 110 may be assigned to the power take off, beacon 1, beacon 2, corner strobes, upper lights, lower lights, controls, tool lights, driver side lights, passenger side lights, auxiliary 1 and auxiliary 2. In a typical marine installation, switches 110 may instead be assigned to the anchor light, bow light, bilge pump, stern light, mast head light, winches, sump pump, forward cabin light, electronics, refrigeration, disposal pump and water pump. Fig. 6 is a schematic diagram illustrating the inputs and outputs of a typical logic control unit 120 utilized in a "spoke and hub" network control system of this invention, located in a central point in the system. Logic control unit 120 may include power supply 122, with keypad connections 124 and power distribution center connections 126, RS-485 transceivers 128, through which all keypad data 130 and power distribution center data 132 is directed, and microprocessor 134, such as an AT89C2051 (ATMEL) . Microprocessor 134 includes, processes, and controls the data from transceivers 128, keypad status
135, and PDC and associated status 136, again in a manner well known in the art. Logic control unit 120 may further include an additional RS-485 transceiver 128a for future
expansion.
While this invention has been described in connection with preferred embodiments thereof, it is obvious that modifications and changes therein may be made by those skilled in the art to which it pertains without departing from the spirit and scope of the invention. Accordingly, the scope of this invention is to be limited only by the appended claims and equivalents .