摘要:
In order to enhance stability of a discharge lamp at the time of dimming lighting even in the case where a light output is lowered, a direct current superimposing circuit superimposes a direct current voltage on an alternating current voltage applied to a fluorescent lamp, and a dimming signal correction circuit receives a detection value of a direct current voltage detection circuit and a dimming signal that is from an outside, outputs a dimming signal higher in level than the dimming signal in the case where the detection value of the direct current voltage detection circuit exceeds a first threshold value, and decreases the level of the outputted dimming signal to the level of the inputted dimming signal in the case where the detection value of the direct current voltage detection circuit falls down below a second threshold value that is equal to or less than the first threshold value. Then, an amount of alternating current power supplied to the fluorescent lamp by an inverter circuit is increased and decreased in response to fluctuations of the level of the dimming signal outputted by the dimming signal correction circuit, whereby the fluorescent lamp is dimmed.
摘要:
In order to enhance stability of a discharge lamp at the time of dimming lighting even in the case where a light output is lowered, a direct current superimposing circuit superimposes a direct current voltage on an alternating current voltage applied to a fluorescent lamp, and a dimming signal correction circuit receives a detection value of a direct current voltage detection circuit and a dimming signal that is from an outside, outputs a dimming signal higher in level than the dimming signal in the case where the detection value of the direct current voltage detection circuit exceeds a first threshold value, and decreases the level of the outputted dimming signal to the level of the inputted dimming signal in the case where the detection value of the direct current voltage detection circuit falls down below a second threshold value that is equal to or less than the first threshold value. Then, an amount of alternating current power supplied to the fluorescent lamp by an inverter circuit is increased and decreased in response to fluctuations of the level of the dimming signal outputted by the dimming signal correction circuit, whereby the fluorescent lamp is dimmed.
摘要:
An electronic ballast is capable of inhibiting ballast shutdown caused by erroneously determining a fault condition. The ballast includes a DC power supply circuit for outputting DC power, a power conversion circuit that appropriately converts DC power outputted by the DC power supply circuit and outputs it to a discharge lamp, a DC voltage droop detection circuit for determining existence/absence of a fault condition in the DC power supply circuit 1, a lamp end of life detection circuit for determining existence/absence of a fault condition of the discharge lamp; and a sequence control circuit and a shutdown control circuit that control at least the power conversion circuit according to detection by the DC voltage droop detection circuit the discharge lamp life detection circuit. When a fault is determined in both the DC voltage droop detection circuit and the discharge lamp life detection circuit, an operation according to the detection of the DC voltage droop detection circuit, the sequence control circuit lowers the output of the power conversion circuit 2 is performed in priority to an operation that, according to the detection of the discharge lamp life detection circuit, the shutdown control circuit shuts down the power conversion circuit
摘要:
An illumination apparatus, which controls a supply power supplied to a lamp according to an accumulated interval of on-time and a light control signal, is configured in which a maximum supply power supplied to the lamp according to the accumulated interval of on-time is supplied to the lamp when the supply power to the lamp corresponding to the light control signal is above the maximum supply power to the lamp according to the accumulated interval of on-time at a point when the illumination apparatus is turned on or the lamp starts lighting. When the light control signal is operated so as to exceed a level of the maximum supply power to the lamp according to the accumulated interval of on-time or the light control signal varies more than a prescribed level, the supply power is shifted to an adjustable condition so as to be higher than the maximum supply power to the lamp according to the accumulated interval of on-time.
摘要:
An illumination lighting apparatus is connected to, as an external apparatus, any of a human body sensing sensor configured to detect presence/absence of a person, an illuminance sensor configured to detect space illuminance, and a dimmer which arbitrarily adjusts the space illuminance, and is configured to produce an output control signal for controlling an optical output of a light source based on a signal output from the external apparatus. The illumination lighting apparatus includes: an external apparatus determining unit configured to determine which kind of the external apparatus is connected based on the signal output from the external apparatus; and a signal processing unit configured to produce the output control signal based on the signal output from the external apparatus.
摘要:
An illumination lighting apparatus is connected to, as an external apparatus, any of a human body sensing sensor configured to detect presence/absence of a person, an illuminance sensor configured to detect space illuminance, and a dimmer which arbitrarily adjusts the space illuminance, and is configured to produce an output control signal for controlling an optical output of a light source based on a signal output from the external apparatus. The illumination lighting apparatus includes: an external apparatus determining unit configured to determine which kind of the external apparatus is connected based on the signal output from the external apparatus; and a signal processing unit configured to produce the output control signal based on the signal output from the external apparatus.
摘要:
An illumination apparatus, which controls a supply power supplied to a lamp according to an accumulated interval of on-time and a light control signal, is configured in which a maximum supply power supplied to the lamp according to the accumulated interval of on-time is supplied to the lamp when the supply power to the lamp corresponding to the light control signal is above the maximum supply power to the lamp according to the accumulated interval of on-time at a point when the illumination apparatus is turned on or the lamp starts lighting. When the light control signal is operated so as to exceed a level of the maximum supply power to the lamp according to the accumulated interval of on-time or the light control signal varies more than a prescribed level, the supply power is shifted to an adjustable condition so as to be higher than the maximum supply power to the lamp according to the accumulated interval of on-time.
摘要:
To provide, in a frequency synthesizer including: a variable attenuator provided at a subsequent stage of a voltage controlled oscillator; a detector; and a control unit outputting a control voltage for adjusting an attenuation amount of the variable attenuator via a digital/analog converter in accordance with a detection voltage, a technology with which a spurious due to a change in an output of the digital/analog converter can be suppressed. A low-pass filter is provided between an output side of a digital/analog converter and a variable attenuator to cut a frequency component corresponding to an overshoot generated when an output of the digital/analog converter is changed. Further, a period of time from when a control unit outputs a control voltage to when it reads a signal level detected by a detector is set to a period of time longer than a time constant of the low-pass filter determined by a cut-off frequency of the low-pass filter so that no influence is exerted on an operation of automatically controlling the signal level.
摘要:
A VCO driving circuit and a frequency synthesizer wherein the impedance viewed from a VCO control terminal is reduced to prevent the VCO phase noise characteristic from degrading. A VCO driving circuit and a frequency synthesizer having the VCO driving circuit, which comprises a coarse adjustment DAC that receives a digital data, which has a coarse adjustment frequency, to output an analog signal; a fine adjustment DAC that receives a digital data, which has a fine adjustment frequency, to output an analog signal; a low response speed LPF5 that removes noise from the output signal from the coarse adjustment DAC and then provides the resultant signal as an input to a VCO control terminal; a high response speed LPF7 that converts the output signal from the fine adjustment DAC to a voltage, thereby smoothing the signal; a resistor that connects an input stage of the LPF5 to that of the LPF7; and a capacitor used for providing a capacitive coupling such that the output of the LPF7 is added to that of the LPF5.
摘要:
Provided is an oscillation frequency control circuit for correcting its frequency, keeping the oscillation frequency stable when self-oscillating, and oscillating with a control voltage generated by making a fixed voltage given from outside variable. In the oscillation frequency control circuit, a CPU selects/outputs the control voltage preferentially according to a command of a control voltage selection. If the command is not given and the level of an outside reference signal detected by a detecting circuit is within an adequate range, it turns a select switch on. If the command is not given and the level of the outside reference signal is out of the adequate range, it turns the select switch off and outputs information about pulse generation stored in a memory to a PWM circuit.