Abstract: A lighting device includes a power converter and a controller. The power converter includes a transformer having primary, secondary and tertiary windings, and a switching device electrically connected in series with the primary winding. The controller is configured to measure a signal simulating a primary current flowing through the primary winding based on a voltage occurring across the tertiary winding and detect timing for turning the switching device off based on the signal simulating the primary current.

Abstract: A lighting device includes a power converter, a second switching element and a microcomputer. The power converter is configured to convert DC power that is received from a power supply, and supply an output obtained by the conversion to a load. The second switching element is configured to short-circuit at least one LED of a plurality of LEDs, as part of the load. The microcomputer is configured to control the power converter, and control switching on/off of the second switching element. The microcomputer is configured to reduce an output current of the power converter, in a case where a power supply voltage of the battery is a reference voltage or less. A reduction amount of the output current in an on-state of the second switching element is lower than the reduction amount of the output current in an off-state of the second switching element.

Abstract: A lighting device includes first to third output terminals, a power converter, a bypass switch, and a controller. A first light source is connected between the first and third output terminals. A second light source is connected between the second and third output terminals. The bypass switch is connected between the second and third output terminals. The controller switches the bypass switch between ON-state and OFF-state. The controller controls the power converter to adjust an output current. The controller includes a voltage meter for measuring a voltage corresponding to an output voltage of the power converter. The controller compares a measured voltage of the voltage meter with a first threshold voltage while keeping the bypass switch in OFF-state. The controller compares the measured voltage with a second threshold voltage while keeping the bypass switch in ON-state. The second threshold voltage is smaller than the first threshold voltage.

Abstract: A lighting device includes first to third output terminals, a power converter, a bypass switch, and a controller. A first light source is connected between the first and third output terminals. A second light source is connected between the second and third output terminals. The bypass switch is connected between the second and third output terminals. The controller switches the bypass switch between ON-state and OFF-state. The controller controls the power converter to adjust an output current. The controller includes a voltage meter for measuring a voltage corresponding to an output voltage of the power converter. The controller compares a measured voltage of the voltage meter with a first threshold voltage while keeping the bypass switch in OFF-state. The controller compares the measured voltage with a second threshold voltage while keeping the bypass switch in ON-state. The second threshold voltage is smaller than the first threshold voltage.

Abstract: A microcomputer is configured to perform a first control and a second control. The first control is of: starting operation of a power converter, when a first power supply voltage exceeds a starting voltage; and stopping the operation of the power converter, when the first power supply voltage is below a maintaining voltage. The second control is of: switching off a second switching element, when a second power supply voltage exceeds a first threshold voltage; maintaining an off-state of the second switching element until the second power supply voltage is below a second threshold voltage; and switching on the second switching element, when the second power supply voltage is below the second threshold voltage.

Abstract: A lighting device includes a power converter and a controller. The power converter includes a transformer having primary, secondary and tertiary windings, and a switching device electrically connected in series with the primary winding. The controller is configured to measure a signal simulating a primary current flowing through the primary winding based on a voltage occurring across the tertiary winding and detect timing for turning the switching device off based on the signal simulating the primary current.

Abstract: A microcomputer is configured to perform a first control and a second control. The first control is of: starting operation of a power converter, when a first power supply voltage exceeds a starting voltage; and stopping the operation of the power converter, when the first power supply voltage is below a maintaining voltage. The second control is of: switching off a second switching element, when a second power supply voltage exceeds a first threshold voltage; maintaining an off-state of the second switching element until the second power supply voltage is below a second threshold voltage; and switching on the second switching element, when the second power supply voltage is below the second threshold voltage.

Abstract: A lighting device includes a power converter, a second switching element and a microcomputer. The power converter is configured to convert DC power that is received from a power supply, and supply an output obtained by the conversion to a load. The second switching element is configured to short-circuit at least one LED of a plurality of LEDs, as part of the load. The microcomputer is configured to control the power converter, and control switching on/off of the second switching element. The microcomputer is configured to reduce an output current of the power converter, in a case where a power supply voltage of the battery is a reference voltage or less. A reduction amount of the output current in an on-state of the second switching element is lower than the reduction amount of the output current in an off-state of the second switching element.

Abstract: A discharge lamp lighting device includes a power converter configured to receive a power from a power source, convert it into a voltage required by a discharge lamp and supply the voltage to the discharge lamp; and a controller which controls the power converter to drive the discharge lamp. The controller controls the power supplied to the discharge lamp according to a predetermined power curve. The controller controls the power curve to change based on at least one of a source voltage of the power source, an ambient temperature, a device temperature, a discharge lamp temperature and a discharge lamp voltage, and sets a sustained period of a max power value to a predetermined time period when the lighting of the discharge lamp is performed in a state where the discharge lamp temperature is equal to or less than a reference temperature.

Abstract: A transformer in this invention comprises substrates constructing a primary winding, substrates constructing the secondary winding, and a core member disposed around the substrates. The substrates defining the primary winding are provided with insertion holes for passing a middle leg portion of the core member, and patterned conductors having one turn. The transformer further comprises an interlayer connection member. The interlayer connection member is located inwardly of the patterned conductors of the substrates defining the primary winding. The interlayer connection member is located on the same side of the patterned conductors defining the primary winding. The interlayer connection member is configured to establish the electrical connection of the patterned conductors defining the primary winding.

Abstract: A transformer in this invention comprises substrates constructing a primary winding, substrates constructing the secondary winding, and a core member disposed around the substrates. The substrates defining the primary winding are provided with insertion holes for passing a middle leg portion of the core member, and patterned conductors having one turn. The transformer further comprises an interlayer connection member. The interlayer connection member is located inwardly of the patterned conductors of the substrates defining the primary winding. The interlayer connection member is located on the same side of the patterned conductors defining the primary winding. The interlayer connection member is configured to establish the electrical connection of the patterned conductors defining the primary winding.

Abstract: In a discharge lamp lighting apparatus, a power supplied to a discharge lamp La through a DC-DC converter 1 and an inverter 2 is controlled depending on detection results of a lamp voltage detection unit 6 and a lamp current detection unit 7, and in an electrode heating period an alternation time of an output to the discharge lamp when starting actuation of the discharge lamp is set longer than an alternation time in a steady lighting period, and the alternation time in the electrode heating period is increased depending on lowering of a supply power or current to the discharge lamp. Thus, even when a lamp current is suddenly changed, the discharge lamp is prevented from going off at the time of polarity inversion without lowering a life.

Abstract: In a discharge lamp lighting apparatus, a power supplied to a discharge lamp La through a DC-DC converter 1 and an inverter 2 is controlled depending on detection results of a lamp voltage detection unit 6 and a lamp current detection unit 7, and in an electrode heating period an alternation time of an output to the discharge lamp when starting actuation of the discharge lamp is set longer than an alternation time in a steady lighting period, and the alternation time in the electrode heating period is increased depending on lowering of a supply power or current to the discharge lamp. Thus, even when a lamp current is suddenly changed, the discharge lamp is prevented from going off at the time of polarity inversion without lowering a life.