摘要:
A lamp includes an arc tube and a lighting unit for lighting the arc tube. The lighting unit includes a rectifier circuit, a smoothing circuit for partial smoothing, and an inverter circuit having a pair of switching elements. The smoothing circuit smoothes portions of the output voltage of the rectifier circuit below the first voltage value and outputs a voltage that falls between the first voltage value and the second voltage value. The discharge sustaining voltage of the arc tube is set to fall between the first and second values of the voltage Vdc output from the smoothing circuit.
摘要:
Provided is a lighting unit and a discharge lamp each of which is capable of causing a capacitor to break down by heat generated in a heat generating component, so that circuit operation is safely terminated without any additional cost. A compact self-ballasted fluorescent lamp is provided with a lighting unit (50) housed in a case. The lighting unit (50) causes an arc tube to emit light and is composed of a plurality of electronic components, including a rectifier/smoothing circuit portion, an inverter circuit portion having transistors (Q1 and Q2), a resonant circuit portion, and a preheating circuit portion having a positive temperature coefficient element. Among the plurality of electronic components, the transistors (Q1 and Q2) and the positive temperature coefficient element generate excessive heat when, for example, the lamp is operated at the end of electrode's life. Capacitors (C4 and C6) disposed in the vicinity of the positive temperature coefficient element would break down by heat in a short mode.
摘要:
A lamp includes an arc tube and a lighting unit for lighting the arc tube. The lighting unit includes a rectifier circuit, a smoothing circuit for partial smoothing, and an inverter circuit having a pair of switching elements. The smoothing circuit smoothes portions of the output voltage of the rectifier circuit below the first voltage value and outputs a voltage that falls between the first voltage value and the second voltage value. The discharge sustaining voltage of the arc tube is set to fall between the first and second values of the voltage Vdc output from the smoothing circuit.
摘要:
A lamp includes an arc tube and a lighting unit for lighting the arc tube. The lighting unit includes a rectifier circuit, a smoothing circuit for partial smoothing, and an inverter circuit having a pair of switching elements. The smoothing circuit smoothes portions of the output voltage of the rectifier circuit below the first voltage value and outputs a voltage that falls between the first voltage value and the second voltage value. The discharge sustaining voltage of the arc tube is set to fall between the first and second values of the voltage Vdc output from the smoothing circuit.
摘要:
Disclosed is a dimmable fluorescent lamp operating apparatus which comprises a fluorescent lamp, electrical characteristic detecting element for detecting an electrical characteristic of the fluorescent lamp, an inverter circuit for driving the fluorescent lamp, and a feedback controlling circuit for controlling the drive frequency of the inverter circuit such that the electrical characteristic of the fluorescent lamp becomes a predetermined value, wherein the feedback controlling circuit includes temperature detecting element for detecting the temperature of the fluorescent lamp and wherein the frequency characteristic bandwidth of the feedback controlling circuit is varied based on the detected fluorescent lamp temperature.
摘要:
The present invention provides for a starting switch circuit which is generally applicable to ballasts and fluorescent lamps having different normal rated power from each other. A starting switch circuit includes a serially-connected circuit having a first rectifier circuit, a semiconductor switching element including a control terminal, and a first resistor circuit for detecting a current flowing to the semiconductor switching element, all connected in series; a first timer circuit, connected in parallel to a series circuit of the semiconductor switching element and the first resistor circuit, for switching the semiconductor switching element to OFF state after the semiconductor switching element is in ON state for a predetermined period of time; and a control circuit for controlling the semiconductor switching element.
摘要:
The present invention relates to an inverter driven lamp arrangement. The arrangement provides for the sensing of both lamp voltage and current. The arrangement also provides for a large current during times of low voltage and a small current during times of high voltage. The sensing of lamp current is done by a current detector that is connected to a resonance circuit whose output is applied in signal form to a lamp start control circuit. The resonant circuit is a series connected resonant circuit composed of a choke coil and a first capacitor. This series connected arrangement is further connected in series with a second non-resonant capacitor. Also the arrangement includes circuitry to gradually reduce the frequency of the inverter just after the lamp starts.
摘要:
In a discharge-lamp lighting apparatus for lighting a discharge lamp such as a metal halide lamp, there is provided a lighting control circuit which controls its output in a starting time of the discharge lamp in response to at least a length of the last off-time and an on-time after the start of discharging; and a power supplied to the discharge lamp is controlled in accordance with this output of the lighting control circuit.
摘要:
Provided is a lighting unit and a discharge lamp each of which is capable of causing a capacitor to break down by heat generated in a heat generating component, so that circuit operation is safely terminated without any additional cost. A compact self-ballasted fluorescent lamp is provided with a lighting unit (50) housed in a case. The lighting unit (50) causes an arc tube to emit light and is composed of a plurality of electronic components, including a rectifier/smoothing circuit portion, an inverter circuit portion having transistors (Q1 and Q2), a resonant circuit portion, and a preheating circuit portion having a positive temperature coefficient element. Among the plurality of electronic components, the transistors (Q1 and Q2) and the positive temperature coefficient element generate excessive heat when, for example, the lamp is operated at the end of electrode's life. Capacitors (C4 and C6) disposed in the vicinity of the positive temperature coefficient element would break down by heat in a short mode.
摘要:
Provided is a lighting unit and a discharge lamp each of which is capable of causing a capacitor to break down by heat generated in a heat generating component, so that circuit operation is safely terminated without any additional cost. A compact self-ballasted fluorescent lamp is provided with a lighting unit (50) housed in a case. The lighting unit (50) causes an arc tube to emit light and is composed of a plurality of electronic components, including a rectifier/smoothing circuit portion, an inverter circuit portion having transistors (Q1 and Q2), a resonant circuit portion, and a preheating circuit portion having a positive temperature coefficient element. Among the plurality of electronic components, the transistors (Q1 and Q2) and the positive temperature coefficient element generate excessive heat when, for example, the lamp is operated at the end of electrode's life. Capacitors (C4 and C6) disposed in the vicinity of the positive temperature coefficient element would break down by heat in a short mode.