Abstract:
This document discusses, among other things, systems, devices, and methods of disabling an automatic generator starting (AGS) actuator, such as used with a fuel-powered AC power generator providing AC electrical power to a recreational vehicle (RV) or other vehicle. The AGS actuator is disabled in response to a fault condition, such as may be indicative of a risk of hazardous gas, such as carbon monoxide (CO) accumulating near the vehicle, potentially in an enclosed area. After such disabling is performed, the vehicle driver would then have to consciously re-engage the AGS actuator. Factors useful for determining whether the fault condition exist include, among other things, transmission position, wheel rotation, vehicle engine operation status, ignition status, and/or an exhaust gas sensor.

Description:
TECHNICAL FIELD 
   This document relates generally to electrical power generators and generator sets, and particularly by way of limitation, to automatic generator starting protection. 
   BACKGROUND 
   A fuel-powered AC electrical power generator, which also referred to as a generator set (“genset”), is used to generate electrical power from a fuel source. Examples include, among other things, gasoline-powered and other spark-ignited generators, and diesel-powered generators. Such generators have numerous applications including, among other things, providing electrical power in recreational vehicles (“RVs”), which are typically used for traveling, camping, etc. 
   RVs typically include electrical appliances (e.g., refrigerators, air conditioners, television sets, etc.). These electrical appliances are powered either (1) from “shore power,” e.g., an AC plug-in at a campground; (2) from a DC battery from which AC power is generated using a DC-to-AC inverter; and/or (3) from a fuel-powered AC electrical power generator. 
   Some generators used in RVs include an automatic generator starting (AGS) system. The AGS system automatically turns on the AC generator, such as when shore power is unavailable or insufficient, or when the DC battery is depleted. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings, which are not necessarily drawn to scale, like numerals describe substantially similar components throughout the several views. Like numerals having different letter suffixes represent different instances of substantially similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. 
       FIG. 1  is a conceptualized schematic diagram illustrating generally one example of a system including an automatic generator starting actuator and a disabling mechanism for the same. 
       FIG. 2  is a flow chart illustrating generally one example of a method associated with the system of  FIG. 1 . 
       FIG. 3  is a block diagram illustrating generally one example of how a fault logic circuit determines whether the CO or other exhaust hazard condition exists, such as by using one or more factors as inputs. 
   

   DETAILED DESCRIPTION 
   In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments, which are also referred to herein as “examples,” are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that the embodiments may be combined, or that other embodiments may be utilized and that structural, logical and electrical changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims and their equivalents. 
   In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one. In this document, the term “or” is used to refer to a “nonexclusive or,” unless otherwise indicated. Furthermore, all publications, patents, and patent documents referred to in this document are incorporated by reference herein in their entirety, as though individually incorporated by reference. In the event of inconsistent usages between this documents and those documents so incorporated by reference, the usage in the incorporated reference(s) should be considered supplementary to that of this document; for irreconcilable inconsistencies, the usage in this document controls. 
     FIG. 1  is a conceptualized schematic diagram illustrating generally, by way of example, but not by way of limitation, one example of a system  100 . In this example, the system  100  includes a recreational vehicle (RV) or other vehicle  102 , a fuel-powered AC generator  104 , an automatic generator starting (AGS) actuator circuit  106 , and an AGS disabling circuit  108 . These constituents of the system  100  are illustrated separately for conceptual clarity, however, it is understood that such constituents, or portions thereof, may be integrated together. 
   In this example, the vehicle  102  includes a keyed or other ignition system  110  for controlling a combustion or other vehicle engine  112 . The vehicle engine  112  is coupled to a drive/transmission system  114  for turning wheels  116  to move the vehicle  102 . The vehicle  102  includes a load circuit  118 . The load circuit  118  may include one or more onboard or other electrical appliances. The AC generator  104  is coupled to the vehicle load circuit  118  to provide it with AC electrical power, when needed. In this example, the AC generator  104  includes a fuel input  120  for a gasoline, diesel, or other combustion engine  122  for providing mechanical energy from which electrical energy is generated. The AC generator  104  includes an AC generator power output  124 , which is coupled to the vehicle load circuit  118 . 
   In this example, the AGS actuator  106  includes a load power sensor circuit  126 . The load power sensor circuit  126  includes at least one input coupled to the vehicle load circuit  118  to detect when the vehicle load circuit  118  needs AC electrical power from the AC generator  104  (either alone, or supplementary to AC power being received from any vehicle engine  112  driven AC generator and/or any DC-to-AC power inverter included in the vehicle  102  and/or shore power). The load power sensor  126  includes an output providing a control signal to activate a starter  128 . The starter  128  includes an electrical and/or mechanical output coupled to the generator engine  122  for starting it when AC electrical power is needed from the AC generator  104  by the load circuit  118 . 
   In this example, the AGS disabling circuit  108  includes a fault logic circuit  130 . The fault logic circuit  130  has an output that is coupled to the AGS actuator  106  to disable it when a fault condition indicates a risk of an exhaust hazard. One example of an exhaust hazard includes a high concentration of carbon monoxide (CO) in the ambient air about the vehicle  102 . The high concentration of CO can result from CO in the exhaust stream of the vehicle engine  112  or of the generator engine  122 . In one example, the fault logic circuit  130  includes input(s) for determining the fault condition from one or more of a CO or other exhaust sensor  132 , the vehicle ignition  110 , the vehicle engine  112 , the vehicle drive train or transmission  114 , and/or the vehicle wheels  116 , and/or any other indication correlative to the fault condition, such as when the vehicle is within an enclosed or confined space. In addition to an exhaust hazard from a spark-ignited generator operating within an enclosed or confined space, a diesel generator operating within such a space also presents an inconvenience that could be regarded as an exhaust hazard. 
     FIG. 2  is a flow chart illustrating generally, by way of example, but not by way of limitation, one example of a method associated with the system  100  of  FIG. 1 . At  200 , a fault condition is monitored, as discussed below. At  202 , if the fault condition is present, the AGS actuator  106  is disabled, at  204 , to prevent an ambient CO hazard to humans or animals in or near the vehicle  102  and/or the AC generator  104 . Otherwise, process flow returns to  200  to continue to monitor for the fault condition. 
   Examples of Fault Logic Circuit Inputs 
     FIG. 3  is a block diagram illustrating generally, by way of example, but not by way of limitation, one example of how the fault logic circuit  130  determines whether the CO or other exhaust hazard condition exists, such as by using one or more factors as inputs, examples of which are discussed below. 
   1. Transmission Position Sensor  300 . In one example, the AGS actuator  106  is disabled when the vehicle transmission is switched from a “drive” gear position to a “park” gear position. After such disabling, the user would then have to consciously manually re-enable the AGS actuator, e.g., using a switch, to again permit automatic starting of the AC generator  104  in response to a need for AC power from the AC generator  104  by the load circuit  118 . In one example, the transmission gear position is detected by the fault logic circuit  130  using transmission position status information received from an SAE J1850, an SAE J1939, another data link to the transmission  114 , or a discrete electrical signal. 
   2. Wheel Rotation Sensor  302 . In one example, the AGS actuator  106  is disabled when vehicle wheel rotation indicates that the vehicle  102  has transitioned from moving to stopped. The user would then have to manually re-enable the AGS actuator  106 , as discussed above. In one example, the fault logic circuit  130  includes a timer circuit causing a wait for a predetermined time period after the vehicle  102  stops before disabling the AGS actuator  106 . This prevents unnecessarily disabling the AGS actuator  106 , such as during normal driving stops in vehicle traffic. In one example, wheel rotation information is communicated to the fault logic circuit  130  using a reluctance sensor coupled to at least one of the wheels  116  of the vehicle  102 . In another example, wheel rotation information is communicated to the fault logic circuit  130  using an SAE J1850, an SAE J1939, or another data link providing vehicle speed information. 
   3. Vehicle Engine Operation Sensor  304 . In one example, the AGS actuator  106  is disabled when the vehicle engine  112  is turned from “on” to “off.” The user would then have to manually re-enable the AGS actuator  106 , as discussed above. In one example, such vehicle engine operation status is obtained by monitoring vehicle engine revolutions per minute (rpm), or by monitoring the voltage to various vehicle engine components (e.g., fuel pump, etc.) where such voltage is indicative of whether the vehicle engine is running. In another example, such vehicle engine operation status is obtained from an SAEJ1850, an SAE J1939, or other data link broadcasting rpm information. 
   4. Ignition Status Sensor  306 . In one example, the AGS actuator  106  is disabled when the vehicle ignition key is turned from the “on” position to the “off” position. The user would then have to manually re-enable the AGS actuator  106 , as discussed above. In one example, ignition key position is sensed by monitoring the voltage to the ignition  110 . In another example, such ignition status information is obtained from an SAEJ1850, an SAE J1939, or other data link broadcasting such information. 
   5. Exhaust sensor  132 . In one example, the AGS actuator  106  is disabled when the exhaust sensor  132  indicates that a dangerous amount of hazardous gas is present in the ambient air about the vehicle  102 . The user would then have to manually re-enable the AGS actuator  106 , as discussed above. In one example, the exhaust sensor  132  detects ambient CO concentration. The fault logic circuit  130  compares the ambient CO concentration to a predetermined threshold value. If the ambient CO concentration exceeds the predetermined threshold value, then the fault logic circuit  130  disables the AGS actuator circuit  106 . 
   6. Combinations. In one example, a combination of two or more of the above fault logic circuit  130  inputs are used to disable the AGS actuator  106 . The user would then have to manually re-enable the AGS actuator  106 , as discussed above. 
   Other Sensors 
     FIG. 3  also illustrates several other sensors including a reluctance sensor  310 , a key ignition position sensor  312 , a carbon monoxide sensor  314  and an RPM sensor  316 . Each of the sensors, namely the reluctance sensor  310 , the key ignition position sensor  312 , the carbon monoxide sensor  314  and the RPM sensor  316  provides an input to the fault logic circuit  130 . 
   Other Uses 
   Although the above examples have been discussed to particularly emphasize use with RVs or other vehicles (including boats), certain aspects are also applicable to automatically started fuel-powered engine generators in applications not involving vehicles. 
   CONCLUSION 
   It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, aspects of the above-described embodiments may be used in combination with each other. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.