Abstract: An electronic device according to the present invention includes a power supply unit and a load, the power supply unit including a ground terminal, a rectifier circuit, a circuit section connected to a DC output of the rectifier circuit, the circuit section supplying electric power to the load, a first varistor connected at one end thereof to one input end of the rectifier circuit, a second varistor connected at one end thereof to another input end of the rectifier circuit and connected at another end thereof to another end of the first varistor and an arrester connected at one end thereof to the another end of the second varistor and connected at another end thereof to the ground terminal, wherein an electrostatic capacity of each of the first and second varistors is 40% or more of a sum of earth capacitances of the power supply unit and the load.

Abstract: An input connection part having a first connection part and a second connection part, an anti-surge circuit having a first varistor and a second varistor which are connected in series so as to connect the first connection part and the second connection part, and a lightning arrester device connecting a connection point of the first varistor and the second varistor and a grounding connection part, and a power supply circuit connected to the anti-surge circuit are provided, wherein capacitances of the first varistor and the second varistor are any values from a value of 1.6 times a nominal capacitance of the first varistor and the second varistor to a value of 0.4 times the nominal capacitance.

Abstract: An electronic device according to the present invention includes a power supply unit and a load, the power supply unit including a ground terminal, a rectifier circuit, a circuit section connected to a DC output of the rectifier circuit, the circuit section supplying electric power to the load, a first varistor connected at one end thereof to one input end of the rectifier circuit, a second varistor connected at one end thereof to another input end of the rectifier circuit and connected at another end thereof to another end of the first varistor and an arrester connected at one end thereof to the another end of the second varistor and connected at another end thereof to the ground terminal, wherein an electrostatic capacity of each of the first and second varistors is 40% or more of a sum of earth capacitances of the power supply unit and the load.

Abstract: An input connection part having a first connection part and a second connection part, an anti-surge circuit having a first varistor and a second varistor which are connected in series so as to connect the first connection part and the second connection part, and a lightning arrester device connecting a connection point of the first varistor and the second varistor and a grounding connection part, and a power supply circuit connected to the anti-surge circuit are provided, wherein capacitances of the first varistor and the second varistor are any values from a value of 1.6 times a nominal capacitance of the first varistor and the second varistor to a value of 0.4 times the nominal capacitance.

Abstract: A series load circuit is a circuit formed by connecting a light-emitting device unit 851 (the first load circuit) and a light-emitting device unit 852 (the second load circuit) in series. A voltage generating circuit 111 generates voltage to be applied to the series load circuit. A current detecting circuit 112 detects electric current flowing through the light-emitting device unit 851. A controlling circuit 114 controls the voltage generating circuit 111 so that the electric current detected by the current detecting circuit 112 becomes a predetermined current value.

Abstract: A series load circuit is a circuit formed by connecting a light-emitting device unit 851 (the first load circuit) and a light-emitting device unit 852 (the second load circuit) in series. A voltage generating circuit 111 generates voltage to be applied to the series load circuit. A current detecting circuit 112 detects electric current flowing through the light-emitting device unit 851. A controlling circuit 114 controls the voltage generating circuit 111 so that the electric current detected by the current detecting circuit 112 becomes a predetermined current value.

Abstract: The discharge lamp lighting apparatus includes: a direct current power supply E; switching elements Q1 and Q2 for switching a direct current supplied from the direct current power supply E so as to generate a high frequency current; a discharge lamp load circuit LAC1 which is constructed in a manner that a discharge lamp LA and a coupling capacitor C4 are connected in series, and the discharge lamp LA is lit by a high frequency current generated by the switching elements Q1 and Q2; a switching element control circuit IC1 for controlling the switching elements Q1 and Q2. The discharge lamp lighting apparatus is further provided with a protective circuit NP2 which distinguishes a fault of the discharge lamp LA by detecting a voltage generated in the coupling capacitor C4, and outputs a control signal to the switching element control circuit IC1.

Abstract: A discharge lamp lighting device in which dim control can be performed for a discharge lamp continuously and stably in a wide range, and which is simple in circuit configuration and low in price. The discharge lamp lighting device comprises: an inverter (IV) for turning on/off switching elements (Q2, Q3) by an oscillation output signal of an IV control integrated circuit (IC2) to thereby invert a voltage of a DC power supply (E) into high-frequency electric power, a discharge lamp (LA) capable of being lighted by the high-frequency electric power from the inverter (IV), a feedback circuit (FB) having delay time T (unit: second) expressed by 1/f≦T≦1/10,000 when the frequency of the high-frequency electric power is f, the feedback circuit (FB) including a reference value setting means (R15) for setting a reference value, the feedback circuit outputting a voltage for controlling the IV control integrated circuit (IC2) to make the high-frequency electric power equal to the reference value.

Abstract: A discharge lamp lighting apparatus according to this invention comprises: an inverting circuit for converting a DC input into a high frequency output; a load circuit which is connected to the inverting circuit and is constructed by a plurality of discharge lamps; a detecting resistor connected between a terminal of the inverting circuit and a ground; an integrating circuit for integrating a voltage generated in the detecting resistor; an operational amplifier which receives an output of the integrating circuit as a negative input, receives a predetermined target value as a positive input, and performs an error amplification; a driver for controlling a switching frequency of the inverting circuit on the basis of an output of the operational amplifier; a frequency detecting comparator which inputs the output of the operational amplifier and whose output value is switched in the case where a frequency converted at an input value exceeds a predetermined value; a control circuit for switching an operating state o

Abstract: To provide a high-pressure discharge lamp lighting apparatus which is adapted to be used in common for several kinds of AC voltages such as 100 V and 200 V, which is small in size, and which can secure good starting property with less circuit loss in use at any of the AC voltages, the apparatus is provided with a diode bridge for rectifying an AC voltage, an active filter for converting, with a high power factor, an AC voltage into a DC voltage, a current limiting circuit for controlling the current to be made to flow in the high-pressure discharge lamp, an inverter for converting a DC voltage into a low-frequency AC voltage, a high-voltage pulse circuit for generating a high-voltage pulse for starting the high-pressure discharge lamp, and a control circuit for controlling the active filter, the current limiting circuit, the inverter, a discharge-lamp voltage detecting circuit, a discharge-lamp current detecting circuit and the high-voltage pulse circuit.