Abstract:
An AC power system for recreational vehicle includes an input circuit for receiving alternating current and at least one output circuit providing alternating current to devices. A park brake circuit is provided for producing a vehicle brake signal, deactivation signal, and an ignition circuit provides a vehicle engine ignition signal. An interlock provides for disabling the output circuit in response to at least one of the brake signal and ignition signals.

Description:
[0001]     Recreational vehicles and motor homes may be supplied with three different power sources, namely a landline, which is connected to the recreational vehicle with 120 volt AC power, a motor generator which is carried by the vehicle, and an inverter which converts the 12-volt DC vehicle battery power to 110 volt AC power.  
         [0002]     Often, the recreational vehicles and motor home relies the 120-volt AC power for a number of applications including exterior awnings, electric doors, electric shades, air conditioning, and powered patio extensions.  
         [0003]     It should be clear that many, if not all, of these accessories are restricted to use when the vehicle is parked, i.e. a stationary condition.  
         [0004]     The present invention provides for an alternating current power interlock (ACPI) for providing a disablement of 120-volt AC circuit when recreational vehicles or motor homes are about to be moved and moving. A disablement of 12-volt circuits may also be enabled.  
       SUMMARY OF THE INVENTION  
       [0005]     An AC power system in accordance with the present invention for a recreational vehicle generally includes an input circuit receiving alternating current and at least one output circuit providing alternating current voltage. The output circuit may be utilized for exterior awnings, electric doors, electric shades, air conditioning, and powered patio extensions, as hereinabove noted.  
         [0006]     Park brake circuitry provides a brake signal deactivation signal upon parking brake deactivation. Ignition circuitry provides an ignition signal when the vehicle engine ignition is activated.  
         [0007]     Interlock circuitry, in accordance with the present invention, interconnected with the hereinabove referenced circuitry disables the AC power output circuit in response to at least one of the brake signals and/or the ignition signal.  
         [0008]     The system may include a plurality of output circuits and a plurality of input circuits with the park brake circuitry and ignition circuitry along with the interlock circuitry operating in a manner hereinabove noted. Additional interlocks may be applied such as door switches, pressure switches, security sensor switches and the like.  
         [0009]     In addition, a switch circuit may be provided which temporarily disables the output circuit and thereafter restores the output circuit, as will be hereinafter described in greater detail.  
         [0010]     The interlock circuitry may also include a circuit disabling the output circuit in response to a combination of the brake signal and ignition signal.  
         [0011]     The input circuitry may provide an AC signal upon interruption of alternating current receipt and the interlock circuitry may include circuitry to delay the enabling of the output circuit in response to an absence of the AC signal. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     The present invention may be more clearly appreciated when taken in conjunction with the accompanying drawings in which:  
         [0013]      FIG. 1  is a schematic drawing of the AC power system in accordance with the present invention; and  
         [0014]      FIG. 2  is a block diagram of a connector panel illustrating input and output corresponding to the schematic diagram, as shown in  FIG. 1 . 
     
    
     DETAILED DESCRIPTION  
       [0015]     An AC powered interlock system  10  in accordance with the present invention is shown schematically in  FIG. 1  and  FIG. 2  illustrates a block diagram of connections thereto.  
         [0016]     The system  10  prevents AC accessory operation when the vehicle is moving or when the AC power is interrupted. This is mandatory since many accessories (not shown) are controlled by wall switches or hand held rf remotes (not shown) that are accessible from the interior of the coach. For safety purposes, it is mandatory to prevent accidental or unwanted operation the switches or remote controls when the vehicle is in motion. The AC interlock system  10  in accordance with the present invention provides a safety interlock and prevents inadvertent operation of the AC accessories in unsafe conditions.  
         [0017]     As shown in  FIG. 1 , the ACPI  10  is a “smart power switch” that has a single 120-volt input and four 120-volt outputs. There is a switch that may be electromechanical or electrical that interrupts the phase lead whenever the coach is in motion. It provides a way to disable 120-volt AC circuits in motor homes when the vehicle is in an unsafe condition. This system is also usable for 240-volt AC or DC. A two pole switch may be used to interrupt both phase and neutral power wires.  
         [0018]     The basic unit contains a three-pin AC power connector with phase, neutral, and ground output. This input circuit is from the inverter or AC distribution panel.  
         [0019]     Depending on the current carrying capacity of the switching the ACPI  10  example output circuits are each capable of 3 or 5 amps. These circuits typically go to awning motors but may be used for any of the AC circuits that must be protected from being used when the vehicle is in an unsafe condition.  
         [0020]     Current generation environmental control units (awnings, shades, blinds) (not shown) are provided with remote controls that operate the units from a hand set. The ACPI  10  will disable AC power and therefore render the remote control inoperative when the vehicle is moving. This safety feature can be offered on any device that is AC powered.  
         [0021]     There are four low level input and signal wires identified as +12 volts, (+12 Volt) ground, ignition, and park brake. These signals are commonly available on a recreational vehicle and may be obtained directly or indirectly from the vehicle. Three conditions are identified which will interrupt the AC input: ignition on, park brake off, or AC power intermittent. So, for example, if the ignition switch is on, or if the park brake is disengaged, the AC will be interrupted and any motor or other device on any one of the four output circuits will be rendered inoperative. If the vehicle driver decides to use the park brake only as an interlock and does not hook up the ignition, then the power will be disabled only if the park brake is disengaged. A similar condition exists if the ignition input is used and the park brake is not hooked up.  
         [0022]     Once all of the conditions: park brake engaged, ignition is off, and the AC power is stable, the 120-volt AC input will be switched onto the (four) output circuits after a delay of approximately (20) seconds. This time may be changed to suit the required conditions.  
         [0023]     The above description refers to a power control circuit that has one input and several outputs. It is possible to have almost any number of input and output circuit combinations. The description defines a low cost version that requires only one relay or equivalent (AC) interpreter.  
         [0024]     An important feature of the above circuit is that all of the conditions must be stable for N seconds before the AC power is switched. Another feature is the capability to switch the power at the zero crossing point. Although this is a well-known technique to prevent large switching currents from being switched by the relay or its equivalent, using this provides greater reliability and less stress on the AC switching components.  
         [0025]     The AC input wiring is connected to J 1  and the AC circuits to motors are on J 2 , J 3 , J 4 , and J 5 . There are three wires per circuit. For the AC to be switched on, the ignition must be off and the park brake must be engaged. If these conditions are met, then the AC J 1  will be connected to J 2 , J 3 , J 4 , and J 5  after the conditions are stable for (20) seconds. If a remote control is available, it will operate the motors used in the awnings or shades. If for any reason the AC should be momentarily interrupted, the phase wire of the input will be disconnected from the outputs and remain disconnected until the AC is stable.  
         [0026]     If the unit is used for rf motors, (motors with built-in rf controls) it may be used to separately reprogram motors to accept the rf channel(s). This is done using the four phase interrupt switches, PJ 1 , PJ 2 , PJ 3 , and PJ 4 . For example, if the motor connected to the circuit on J 1  needs to be reprogrammed, PJ 1  is set “on” and switch SW 1  is depressed and switches PJ 2 , PJ 3 , and PJ 4  are set to off. This must be done within one minute of pressing SW 1 . When SW 1  is pressed a second time, the power on J 1  will be cycled and the motor will be reset. If the switch is not pressed within the minute, the system will revert to normal operation. SW 1  provides a way to interrupt the AC for one minute if pressed only once not more often than every two minutes. The LED (D 3 ) will indicate whenever the AC is active.  
         [0000]     Modes of Operation  
         [0000]     1. Disable AC on deactivation of park brake.  
         [0000]     2. Disable AC on activation of ignition.  
         [0000]     3. Disable AC for twenty seconds on momentary “glitch” of AC.  
         [0000]     4. Allow AC “program cycle” when SW 1  pushed once. If pushed again within one minute, AC will perform “program cycle” and stay on.