Abstract: A platform leveling apparatus with a platform attached to a frame, two and only two linear actuators, and one and only one heim joint. The upper ends of the linear actuators are rotatably attached to the front frame member, and the heim joint is connected to the rear frame member. The lower end of the heim joint is connected to an upper end of a heim joint support, and the lower end of the heim joint support is connected to a rear base support by front and/or rear heim joint braces. The rear base support is oriented parallel to the rear frame member when the heim joint is at a centered position, and the rear base support is positioned below a front edge of the rear frame member. The lower ends of the linear actuators are rotatably connected to a first fixed surface.

Abstract: A platform leveling apparatus with a platform attached to a frame, two and only two linear actuators, and one and only one heim joint. The upper ends of the linear actuators are rotatably attached to the front frame member, and the heim joint is connected to the rear frame member. The lower end of the heim joint is connected to an upper end of a heim joint support, and the lower end of the heim joint support is connected to a rear base support by front and/or rear heim joint braces. The rear base support is oriented parallel to the rear frame member when the heim joint is at a centered position, and the rear base support is positioned below a front edge of the rear frame member. The lower ends of the linear actuators are rotatably connected to a first fixed surface.

Abstract: In a method performed by a PoE system, a PSE provides data and operating voltage over Ethernet wires to a PD. Before the full PoE voltage is supplied, the PSE generates a low current signal received by the PD. A circuit in the PD, connected across its input terminals, has a characteristic analog response to the PSE signal corresponding to the PD's PoE requirements, such as whether the PD is a Type 1 or Type 2 PD. The circuit may be a certain value capacitor, zener diode, resistor, or other circuit. The PSE may generate a fixed current, fixed voltage, or time varying signal. Upon the PSE sensing the magnitude of the analog signal response at a particular time, the PSE associates the response with the PoE requirements of the PD. The PSE then applies the full PoE voltage in accordance with the PD's PoE requirements.

Abstract: In a method performed by a PoE system, a PSE provides data and operating voltage over Ethernet wires to a PD. Before the full PoE voltage is supplied, the PSE generates a low current signal received by the PD. A circuit in the PD, connected across its input terminals, has a characteristic analog response to the PSE signal corresponding to the PD's PoE requirements, such as whether the PD is a Type 1 or Type 2 PD. The circuit may be a certain value capacitor, zener diode, resistor, or other circuit. The PSE may generate a fixed current, fixed voltage, or time varying signal. Upon the PSE sensing the magnitude of the analog signal response at a particular time, the PSE associates the response with the PoE requirements of the PD. The PSE then applies the full PoE voltage in accordance with the PD's PoE requirements.

Abstract: In a method performed by a PoE system, a PSE provides data and operating voltage over Ethernet wires to a PD. Before the full PoE voltage is supplied, the PSE generates a low current signal received by the PD. A circuit in the PD, connected across its input terminals, has a characteristic analog response to the PSE signal corresponding to the PD's PoE requirements, such as whether the PD is a Type 1 or Type 2 PD. The circuit may be a certain value capacitor, zener diode, resistor, or other circuit. The PSE may generate a fixed current, fixed voltage, or time varying signal. Upon the PSE sensing the magnitude of the analog signal response at a particular time, the PSE associates the response with the PoE requirements of the PD. The PSE then applies the full PoE voltage in accordance with the PD's PoE requirements.

Abstract: A Power Over Ethernet (PoE) system, or other power over data lines system, includes Power Sourcing Equipment (PSE) providing combined data and voltage over wires to a Powered Device (PD). Since cable length and PD load currents may not be known, there is a variable voltage drop along the cable between the PSE and PD. Prior to the PD being fully powered up, a test is performed by the PSE to determine the actual resistance or voltage drop of the cable, and the results are stored in a memory accessed by the PSE upon powering up. The PSE uses the stored information to adjust its voltage source to provide a target voltage at the PD input during full power operation. This may obviate the need for a voltage regulator at the PD. The test may only be conducted when the PSE is initially powered up or may be conducted periodically.

Abstract: A technique for combining power to a single load from multiple power supplies using power over Ethernet (PoE) is disclosed. Each power supply is coupled to associated power sourcing equipment (PSE) providing PoE, and each PSE has a current limit. The power supplies supply approximately the same voltage, but the output voltages are typically not exactly equal. All the power supplies are connected via diodes to a common load terminal. The power supply outputting the highest voltage first supplies power to the load terminal, since only its diode is forward biased, until a PoE current limit is reached. Then its duty cycle is limited. The load terminal voltage is then inherently lowered to cause the diode of the power supply with the next highest output voltage to connect it to the load to supply additional power to the load as the first power supply continues to supply its limited current.

Abstract: In a method performed by a PoE system, a PSE provides data and operating voltage over Ethernet wires to a PD. Before the full PoE voltage is supplied, the PSE generates a low current signal received by the PD. A circuit in the PD, connected across its input terminals, has a characteristic analog response to the PSE signal corresponding to the PD's PoE requirements, such as whether the PD is a Type 1 or Type 2 PD. The circuit may be a certain value capacitor, zener diode, resistor, or other circuit. The PSE may generate a fixed current, fixed voltage, or time varying signal. Upon the PSE sensing the magnitude of the analog signal response at a particular time, the PSE associates the response with the PoE requirements of the PD. The PSE then applies the full PoE voltage in accordance with the PD's PoE requirements.

Abstract: A technique for combining power to a single load from multiple power supplies using power over Ethernet (PoE) is disclosed. Each power supply is coupled to associated power sourcing equipment (PSE) providing PoE, and each PSE has a current limit. The power supplies supply approximately the same voltage, but the output voltages are typically not exactly equal. All the power supplies are connected via diodes to a common load terminal. The power supply outputting the highest voltage first supplies power to the load terminal, since only its diode is forward biased, until a PoE current limit is reached. Then its duty cycle is limited. The load terminal voltage is then inherently lowered to cause the diode of the power supply with the next highest output voltage to connect it to the load to supply additional power to the load as the first power supply continues to supply its limited current.