Devices, methods, and systems for alternating current circuits for airfield lighting are described herein. One system includes a circuit comprising an isolation transformer, a protection hardware circuit coupled to the isolation transformer, wherein the protection hardware prevents a voltage between an electrical contact of the circuit and a ground contact from meeting or exceeding a threshold voltage, and a load coupled to the protection hardware circuit to receive electrical energy from the isolation transformer.

A resistor bypass circuit for a series lighting circuit includes a plurality of serially connected light sources and a bypass resistor being connected in parallel with at least one of the respective light sources, each respective light source being low wattage and being capable operating on a one hundred percent duty cycle as desired.

A resistor bypass circuit for a series lighting circuit includes a plurality of serially connected light sources and a bypass resistor being connected in parallel with at least one of the respective light sources, each respective light source being low wattage and being capable operating on a one hundred percent duty cycle as desired.

A resistor bypass circuit for a series lighting circuit includes a plurality of serially connected light sources and a bypass resistor being connected in parallel with at least one of the respective light sources, each respective light source being low wattage and being capable operating on a one hundred percent duty cycle as desired.

Devices, methods, and systems for alternating current circuits for airfield lighting are described herein. One system includes a circuit comprising an isolation transformer, a protection hardware circuit coupled to the isolation transformer, wherein the protection hardware prevents a voltage between an electrical contact of the circuit and a ground contact from meeting or exceeding a threshold voltage, and a load coupled to the protection hardware circuit to receive electrical energy from the isolation transformer.

An airfield runway lamp controller is described herein. One airfield runway lamp controller includes a current sense transformer configured to detect a failure of a light source of an airfield runway lamp, and an alternating current (AC) switch configured to shunt the light source of the airfield runway lamp upon the current sense transformer detecting a failure of the light source.

The invention relates to a short-circuit fault detection illumination device (1) for a motor vehicle headlight, comprising a voltage input (SE) and a terminal (ME) for connection to earth potential, a power branch (LS) supplied via the voltage input (SE), which comprises a number of light sources (2) to be monitored, wherein this number is at least two, wherein the light sources (2) are designed to emit the light of the illumination device (1) and the light sources (2) are connected to one another in series within the power branch (LS),
wherein the illumination device (1) further has an auxiliary branch (HS) with transistors (3) arranged therein and connected to one another in series, wherein each light source (2) of the power branch (LS) is associated with one of the transistors (3), and thus a monitoring pair (P1, P2, P3, P4), consisting of a light source (2) to be monitored and a transistor (3) assigned for monitoring, is formed, wherein each transistor (3) is coupled to the cathode and anode of the light source (2) in such a manner that the voltage that drops across the light source (2) in normal operation is used to connect the transistor (3), and in the event of a short circuit of the light source (2), the voltage drop caused by the short circuit leads to a blocking of the transistor (3) and thus of the auxiliary branch (HS), wherein the short-circuit fault detection illumination device (1) further has a fault detection device (6) coupled to the auxiliary branch (HS), which is designed to output an error signal (SF) or trigger an error routine (FR) in the event of the auxiliary branch being blocked.

The invention relates to power supply systems. There is provided an apparatus and a method for supplying electric power to an electric device. In the method an indication of a desired power level to be supplied to the electric device is obtained. Electric power is received as DC power by a constant current regulator unit, which inverts the DC power to AC power and supplies the AC power to a reactance (T1) to be transformed to an output power. The output power is supplied from the reactance (T1) to the electric device. The method further comprises adjusting the AC power supplied to the reactance (T1) by using at least two of the following: voltage level of the AC power; the frequency of the AC power; a waveform of the AC power.

A return-type wiring structure having multiple devices and units capable of being flexibly increased and decreased comprising a plurality of light-emitting devices or illuminating devices, a power plug or an input terminal, and a power socket or an output terminal; the plurality of light-emitting devices or illuminating devices are divided into a plurality of collection units; each collection unit comprises at least two light-emitting devices or illuminating devices; the plurality of light-emitting devices or illuminating devices of each collection unit are first connected in parallel, and then the plurality of collection units are connected in series, thereby forming a total connection unit.

Devices, methods, and systems for alternating current circuits for airfield lighting are described herein. One system includes a circuit comprising an isolation transformer, a protection hardware circuit coupled to the isolation transformer, wherein the protection hardware prevents a voltage between an electrical contact of the circuit and a ground contact from meeting or exceeding a threshold voltage, and a load coupled to the protection hardware circuit to receive electrical energy from the isolation transformer.