Abstract: A switching power supply device includes a case, a board that has circuit parts containing a switching element mounted thereon and is accommodated in the case, and a heat sink that is provided in the case so as to partition the inside of the case into a part mount chamber having the board accommodated therein and an air flow path through which air flows. The switching element of the circuit parts is mounted on the board while brought into contact with a surface of the heat sink that faces the part mount chamber, and cooled through the heat sink by the air flowing in the air flow path.

Abstract: A lighting device has a direct-current power generation circuit, a rectangular-wave generation circuit, a pulse generating circuit, lamp-voltage detection means, and pulse-generation command means. The direct-current power generation circuit generates direct-current power from external power. The rectangular-wave generation circuit converts the direct-current power to rectangular-wave alternating-current power. The pulse generating circuit superposes high-voltage pulses on the rectangular-wave power output from the rectangular-wave generation circuit and starts a discharge lamp. The lamp-voltage detection means detects, in digital form, a lamp voltage supplied to the discharge lamp. The pulse-generation command means issues a pulse generation command to the pulse generating circuit when the value detected by the lamp-voltage detection means reaches a predetermined no-load-voltage determination level.

Abstract: A lighting device has a direct-current power generation circuit, a rectangular-wave generation circuit, a pulse generating circuit, lamp-voltage detection means, and pulse-generation command means. The direct-current power generation circuit generates direct-current power from external power. The rectangular-wave generation circuit converts the direct-current power to rectangular-wave alternating-current power. The pulse generating circuit superposes high-voltage pulses on the rectangular-wave power output from the rectangular-wave generation circuit and starts a discharge lamp. The lamp-voltage detection means detects, in digital form, a lamp voltage supplied to the discharge lamp. The pulse-generation command means issues a pulse generation command to the pulse generating circuit when the value detected by the lamp-voltage detection means reaches a predetermined no-load-voltage determination level.

Abstract: A switching power supply device includes a case, a board that has circuit parts containing a switching element mounted thereon and is accommodated in the case, and a heat sink that is provided in the case so as to partition the inside of the case into a part mount chamber having the board accommodated therein and an air flow path through which air flows. The switching element of the circuit parts is mounted on the board while brought into contact with a surface of the heat sink that faces the part mount chamber, and cooled through the heat sink by the air flowing in the air flow path.