An input detection and protection circuit and an AC electronic ballast for HID lamps, including a power input circuit performing a first limitation to an input surge voltage and then performing a second limitation to a residual voltage from the first input surge voltage limitation; an input voltage acquisition circuit feeding back an input voltage to an MCU chip; a pull-in circuit for a relay connecting to a relay in the power input circuit; a PFC circuit, and an MCU chip controlling the PFC circuit to switch on and off according to voltage values input by the input voltage acquisition circuit, and controlling pull-in and drop-out of the relay through the pull-in circuit for the relay.

A discharge lamp drive device includes a discharge lamp driver adapted to supply a drive current to a discharge lamp having a first electrode and a second electrode, a control section adapted to control the discharge lamp driver, and a storage section adapted to store a plurality of drive patterns of the drive current. Each of the plurality of drive patterns has a plurality of drive parameters. The control section executes at least three of the drive patterns in a case in which drive power to be supplied to the discharge lamp is in a predetermined power band, and in a case in which an inter-electrode voltage of the discharge lamp is a predetermined voltage value. Any two of the at least three drive patterns are different from each other in a value of at least one of the plurality of drive parameters.

An input detection and protection circuit and an AC electronic ballast for HID lamps, including a power input circuit performing a first limitation to an input surge voltage and then performing a second limitation to a residual voltage from the first input surge voltage limitation; an input voltage acquisition circuit feeding back an input voltage to an MCU chip; a pull-in circuit for a relay connecting to a relay in the power input circuit; a PFC circuit, and an MCU chip controlling the PFC circuit to switch on and off according to voltage values input by the input voltage acquisition circuit, and controlling pull-in and drop-out of the relay through the pull-in circuit for the relay.

A discharge lamp drive device includes a discharge lamp driver adapted to supply a drive current to a discharge lamp, a control section adapted to control the discharge lamp driver, and a storage section adapted to store a plurality of drive patterns of the drive current. Each of the drive patterns has a plurality of drive parameters. The plurality of drive patterns includes a first drive pattern and a second drive pattern different from each other in a value of at least one of the plurality of drive parameters. The control section is configured to execute the first drive pattern and the second drive pattern in accordance with at least one of accumulated lighting time of the discharge lamp and an individual of the discharge lamp in a case in which an inter-electrode voltage of the discharge lamp is at a predetermined voltage value.

A discharge lamp drive device includes a discharge lamp driver adapted to supply a drive current to a discharge lamp, a control section adapted to control the discharge lamp driver, and a storage section adapted to store a plurality of drive patterns of the drive current. Each of the drive patterns has a plurality of drive parameters. The plurality of drive patterns includes a first drive pattern and a second drive pattern different from each other in a value of at least one of the plurality of drive parameters. The control section is configured to execute the first drive pattern and the second drive pattern in accordance with at least one of accumulated lighting time of the discharge lamp and an individual of the discharge lamp in a case in which an inter-electrode voltage of the discharge lamp is at a predetermined voltage value.

A discharge lamp drive device includes a discharge lamp driver adapted to supply a drive current to a discharge lamp having a first electrode and a second electrode, a control section adapted to control the discharge lamp driver, and a storage section adapted to store a plurality of drive patterns of the drive current. Each of the plurality of drive patterns has a plurality of drive parameters. The control section executes at least three of the drive patterns in a case in which drive power to be supplied to the discharge lamp is in a predetermined power band, and in a case in which an inter-electrode voltage of the discharge lamp is a predetermined voltage value. Any two of the at least three drive patterns are different from each other in a value of at least one of the plurality of drive parameters.

A device for providing power to a light arrangement (1) having a current conducting state and a current blocking state. The device comprises a storage circuit (2) with a capacitor (21) coupled to the light arrangement (1) and a resistor (22) located in parallel to the capacitor, a first determination circuit (3) for determining the state of the lighting arrangement, a second determination circuit (4) for, in the current blocking state, determining points of two discharging curves of the storage circuit, a derivation circuit (5) for deriving a condition of the storage circuit, such as life-end, from the discharging curves, a switch circuit (6) comprising an element (61), wherein the switch circuit is configured to switch the element (61) in parallel to the capacitor (21), whereby a first discharging curve is determined with the element being disconnected from the capacitor and a second discharging curve is determined with the element being connected to the capacitor, the capacitor discharging via both the resistor (22) and the element (61). The element (61) may comprise a resistor, a capacitor or an inductor.

A device for providing power to a light arrangement (1) having a current conducting state and a current blocking state. The device comprises a storage circuit (2) with a capacitor (21) coupled to the light arrangement (1) and a resistor (22) located in parallel to the capacitor, a first determination circuit (3) for determining the state of the lighting arrangement, a second determination circuit (4) for, in the current blocking state, determining points of two discharging curves of the storage circuit, a derivation circuit (5) for deriving a condition of the storage circuit, such as life-end, from the discharging curves, a switch circuit (6) comprising an element (61), wherein the switch circuit is configured to switch the element (61) in parallel to the capacitor (21), whereby a first discharging curve is determined with the element being disconnected from the capacitor and a second discharging curve is determined with the element being connected to the capacitor, the capacitor discharging via both the resistor (22) and the element (61). The element (61) may comprise a resistor, a capacitor or an inductor.

The present disclosure is directed to a method for detecting a failure in a signal light. In one embodiment, the method includes monitoring operation of one or more light emitting diodes (LEDs) of the signal light coupled to a constant current driver, detecting a short circuit in at least one of the one or more LEDs and signaling a failure in the signal light when the short circuit is detected.

Lighting power supply system (1) including a mains input converter (11) operable to provide power, a controller (17) operable to control at least one element of the lighting system, a controller bus (26) and a controller interface (25) operable to provide control signals from the bus to the lighting system. An auxiliary converter (43) powers the lighting system from the bus and it may allow the controller to continue to be powered when the mains input is absent and an emergency battery (19) is depleted.