Discharge lamp lighting apparatus and luminaire using the same

A discharge lamp lighting apparatus, comprising:

• a DC power supply, generating a direct current voltage;
• an inverter circuit, switching the direct current voltage at a high frequency, and including one bipolar transistor, which is turned on by a feedback signal of the high frequency voltage and turned off by an off-switching signal of a control circuit, and a resonance circuit resonated by the switching operations;
• a discharge lamp, operated by the high frequency voltage;
• a current transformer, feeding back a lamp current of the discharge lamp to turn on the bipolar transistor;
• a base current cut-off device responsive to the off-switching signal of the control circuit to cut off a base current of the bipolar transistor;
• and
• the control circuit, provided with a timer and an oscillator, wherein the timer determines operation-durations including a preheating mode, a starting mode and a lighting mode of the discharge lamp, and supplies a starting current to the bipolar transistor, and the oscillator provides the base current cut-off device with the off-switching signal which varies to regulate an on-duration of the base current cut-off device according to the each mode.

A discharge lamp lighting apparatus, comprising:

• a first DC power supply, generating a first direct current voltage;
• an inverter circuit, switching the first direct current voltage at a high frequency, and including one bipolar transistor, which is turned on by a feedback signal of the high frequency voltage and turned off by an off-switching signal of a control circuit, and a resonance circuit resonated by the switching operations;
• a discharge lamp, operated by the high frequency voltage;
• a base current cut-off device responsive to the off-switching signal of the control circuit to cut off a base current of the bipolar transistor;
• a starting current controller, controlling a second direct current voltage supplied from a second DC power supply provided in the control circuit to the base of the bipolar transistor for a predetermined period in a starting operation;
• and
• the control circuit, provided with an oscillator defining the high frequency for operating the inverter and regulating the frequency of the off-switching signal.

A discharge lamp lighting apparatus, comprising:

• a DC power supply, generating a direct current voltage;
• an inverter circuit, switching the direct current voltage at a high frequency, and including one bipolar transistor, which is turned on by a feedback signal of the high frequency voltage and turned off by an off-switching signal of a control circuit, and a resonance circuit resonated by the switching operations;
• a discharge lamp, operated by the high frequency voltage;
• and
• the control circuit, provided with a timer regulating operation modes of the discharge lamp, and an oscillator generating the off-switching signal according to each operation mode of the discharge lamp.

A discharge lamp lighting apparatus, comprising:

• a DC power supply, generating a direct current voltage;
• an inverter circuit, switching the direct current voltage at a high frequency, and including one bipolar transistor, which is turned on by a feedback signal of the high frequency voltage and turned off by an off-switching signal of a control circuit, and a resonance circuit resonated by the switching operations;
• a discharge lamp, operated by the high frequency voltage;
• a current transformer, having a primary winding of the transformer inserted in a current path of the discharge lamp and a secondary winding inserted in a base current path of the bipolar transistor, thereby feeding back a lamp current of the discharge lamp to the base of the bipolar transistor to turn on the bipolar transistor through the primary winding and the secondary winding;
• a base current cut-off device responsive to the off-switching signal of the control circuit to cut off a base current of the bipolar transistor;
• and
• the control circuit, provided with a timer regulating operation modes of the discharge lamp, and an oscillator providing the base current cut-off device with the off-switching signal which varies in its frequency to regulate an on-duration of the base current cut-off device according to the operation mode of the discharge lamp.