摘要:
An electronic ballast for a discharge lamp includes a predictive circuit and a correction circuit in addition to a power conversion circuit including an inverter circuit and a resonant circuit, a drive circuit and a frequency control circuit. The inverter circuit applies load voltage across a load circuit including the lamp via the resonant circuit. The predictive circuit predicts a resonance frequency of the combination of the resonant circuit and the load circuit after ignition of the lamp. The resonance frequency is predicted based on an input signal representing the load voltage in the period of time from the start of sweep of the inverter circuit's operating frequency through a time point immediately after ignition of the lamp. The correction circuit changes the end frequency of the sweep to the resonance frequency.
摘要:
Electrodeless discharge lamp lighting device. Start circuit 19 sweeps operating frequency of resonance circuit 16 from start frequency to end frequency of resonance frequency side through drive circuit 18 and DC/AC conversion circuit 15, and starts electrodeless discharge lamp 13. Control circuit 10 increases or decreases variable power into circuit 18 so that detection current comes to equal prescribed current for shifting the operating frequency to middle range frequency between the start frequency and the end frequency. The prescribed current is set so that the detection voltage in case of the middle range frequency becomes lower than that in case of the end frequency. Capacitor 106 constituting integration circuit starts suppression of operation of circuit 10 when lamp 13 is started, and holds the suppression during at least start mode. Accordingly, it is possible to stably start lamp 13 and control stress on circuit(s) after lamp 13 is successfully started.
摘要:
An induction lamp lighting device includes an induction coil arranged adjacent to an induction lamp; a direct current power supply circuit for outputting a direct current voltage; a high-frequency power supply circuit for converting the direct current voltage to an alternating current voltage and supplying the alternating current voltage to the induction coil; and a control circuit for controlling the direct current power supply circuit and the high-frequency power supply circuit. The control circuit performs a startup preparation operation by which to control the high-frequency power supply circuit so that, immediately after the alternating current voltage begins to be outputted from the high-frequency power supply circuit to the induction coil, the alternating current voltage is gradually increased to such a voltage value as not to generate arc discharge in the induction lamp and then kept at the voltage value for a specified time.
摘要:
An electric-discharge lamp lightning device includes a first frequency controller for sweeping a switching frequency so that the output of an inverter is gradually increased in order to allow an electric-discharge lamp to be started and lighted, and a second frequency controller for detecting the output power of the inverter by a current flowing in a resonant circuit and controlling the switching frequency so that the output power is set to be a target value after the discharge lamp is started and lighted. The first frequency controller includes a holding means for holding the switching frequency just after the lighting detection when the output power is smaller than the target value at the lighting detection of the electric-discharge lamp by a lighting detection circuit.
摘要:
A dimmable electronic ballast for an electrodeless discharge lamp comprises an inverter circuit, a resonance circuit, an induction coil and a start circuit. The start circuit has a variable time constant. The start circuit sweeps a drive frequency of the inverter circuit through a time constant for start or restart so that the voltage applied across the coil is raised from voltage lower than start voltage and restart voltage for starting and restarting the lamp to voltage higher than the start voltage and the restart voltage. The time constant for start during a start period for starting the lamp is larger than the time constant for restart during a restart period for restarting the lamp.
摘要:
An induction lamp lighting device includes an induction coil arranged adjacent to an induction lamp; a direct current power supply circuit for outputting a direct current voltage; a high-frequency power supply circuit for converting the direct current voltage to an alternating current voltage and supplying the alternating current voltage to the induction coil; and a control circuit for controlling the direct current power supply circuit and the high-frequency power supply circuit. The control circuit performs a startup preparation operation by which to control the high-frequency power supply circuit so that, immediately after the alternating current voltage begins to be outputted from the high-frequency power supply circuit to the induction coil, the alternating current voltage is gradually increased to such a voltage value as not to generate arc discharge in the induction lamp and then kept at the voltage value for a specified time.
摘要:
A ballast for an electrodeless discharge lamp includes a high frequency power supply that supplies a high frequency electric power to an induction coil for operating the lamp. A dimmer controller generates a control signal in response to a dimmer command designating a varying dimming ratio. The control signal defines a first period Ton in which the power supply is controlled to apply a coil voltage of a first level V1 to the induction coil for operating the lamp. The first period is followed by a second period Toff in which the power supply is controlled to apply the coil voltage of a second level V2 that is lower than the first level and fails to sustain the lamp. The control signal defines, between the second period and the first period, a starting period Tst in which the coil voltage increases continuously for smooth transition from an off-condition to an on-condition of the lamp.
摘要:
An electronic ballast for a discharge lamp includes a predictive circuit and a correction circuit in addition to a power conversion circuit including an inverter circuit and a resonant circuit, a drive circuit and a frequency control circuit. The inverter circuit applies load voltage across a load circuit including the lamp via the resonant circuit. The predictive circuit predicts a resonance frequency of the combination of the resonant circuit and the load circuit after ignition of the lamp. The resonance frequency is predicted based on an input signal representing the load voltage in the period of time from the start of sweep of the inverter circuit's operating frequency through a time point immediately after ignition of the lamp. The correction circuit changes the end frequency of the sweep to the resonance frequency.
摘要:
An electric-discharge lamp lightning device includes a first frequency controller for sweeping a switching frequency so that the output of an inverter is gradually increased in order to allow an electric-discharge lamp to be started and lighted, and a second frequency controller for detecting the output power of the inverter by a current flowing in a resonant circuit and controlling the switching frequency so that the output power is set to be a target value after the discharge lamp is started and lighted. The first frequency controller includes a holding means for holding the switching frequency just after the lighting detection when the output power is smaller than the target value at the lighting detection of the electric-discharge lamp by a lighting detection circuit.
摘要:
A dimmable electronic ballast for an electrodeless discharge lamp comprises an inverter circuit, a resonance circuit, an induction coil and a start circuit. The start circuit has a variable time constant. The start circuit sweeps a drive frequency of the inverter circuit through a time constant for start or restart so that the voltage applied across the coil is raised from voltage lower than start voltage and restart voltage for starting and restarting the lamp to voltage higher than the start voltage and the restart voltage. The time constant for start during a start period for starting the lamp is larger than the time constant for restart during a restart period for restarting the lamp.