JP2010287311A - Electric circuit and luminaire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-voltage constant-current circuit, which can be protected from instantaneously caused high voltage or overcurrent, and thus can respond to a lighting device for conventional fluorescent lamps and LED fluorescent lamps of glow type, rapid type and inverter type. <P>SOLUTION: The high-voltage constant-current circuit includes: a rectification unit which converts alternating current (AC) to direct current (DC); a current amplification unit which amplifies the DC converted by the rectification unit; a constant current control unit; and a light source. The rectification unit is composed of a plurality of rectifiers connected in parallel, and is configured to control overcurrent generated in a pulse-like manner. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electric circuit and a lighting fixture.

  Currently, there are four types of fluorescent lamp lighting devices that are generally used: glow type, rapid type, inverter type, and multi-inverter type. The input current required for the glow-type, rapid-type, and inverter-type fluorescent lamp lighting devices is 200 to 265V, and can be adequately handled by household voltages of 100V and 200V. In particular, inverter-type fluorescent lamp lighting devices that have been widely used in recent years include a series resonance circuit (lighting load circuit) composed of a filament, a ballast (current limiting coil), and a capacitor, and a high-frequency inverter for commercial power supply 50/60 Hz. The fluorescent lamp is turned on when a single frequency (20,000 to 50,000 Hz) near the resonance frequency input from the high-frequency inverter circuit to the lighting load circuit generates a high voltage due to the resonance action. The flickering of the fluorescent lamp is reduced by setting the steady lighting state at a low voltage with the current of.

  However, when the life of the fluorescent tube reaches the end, the current in the fluorescent tube decreases and approaches the series resonance state, so that the input current becomes larger than the initial input current, leading to an increase in the temperature of the current limiting coil. Furthermore, if the current in the fluorescent tube increases and exceeds the allowable current of the current-limiting coil, the current-limiting coil itself loses its current-limiting capability, causing a rapid current increase (occurrence of overcurrent). If this happens, the current-limiting coil will not only be destroyed by a sudden rise in temperature, but it will also break down the high-frequency inverter circuit and break the filament of the fluorescent lamp, making the entire device unusable and causing a fire. There is also a risk of occurrence. Currently, like the “overcurrent detection circuit” described in Patent Document 1, a current detection resistor and a current amplification comparison circuit for detecting a load current are provided between a rectifying / smoothing means for rectifying an input current and an inverter circuit. When the current in the circuit exceeds a certain specified value, the signal is detected to control the drive of the inverter circuit, thereby preventing the circuit from being destroyed by the overcurrent generated.

Moreover, although LED recommended as an energy-saving lighting fixture has spread as an LED bulb, the spread as an LED fluorescent lamp has been delayed. One of the causes is that the LED fluorescent lamp lighting device does not require the ballast (glow type, rapid type and inverter type) necessary for the conventional fluorescent lamp lighting device, and the conventional fluorescent lamp lighting device is used for LED fluorescence. When lighting the lamp, take measures such as changing the wiring so that the ballast does not operate, or depending on the type, there are things that can not be used even if the wiring is changed. It is difficult to use the same circuit, and a special circuit is required. Therefore, by using an LED fluorescent lamp that should be used for the purpose of energy saving, on the contrary, a cost burden is imposed. In response to such a problem, Patent Document 2 discloses an LED illumination lamp that can be applied to any fluorescent lamp lighting device without any hindrance to conventional glow type, rapid type, and inverter type fluorescent lamp lighting devices. Has been.
JP 2008-17649 A JP 2008-277188 A

  However, in Patent Document 1, not only can an overcurrent be detected and controlled to flow in the circuit, but the device itself can be reduced in size, but the overcurrent detection current value and voltage can be reduced in advance. Since it is necessary to estimate the difference and determine the resistance value of the current detection resistor, there is a problem that it may not be possible to deal with a case where a large voltage is instantaneously applied.

  The invention of Patent Document 2 is compatible with conventional glow type, rapid type and inverter type fluorescent lamp lighting devices, but is common to all as shown in FIGS. 3 (a) to 3 (c). Therefore, there is a problem that some construction or a new fluorescent lamp lighting device is required when using the circuit.

  The present invention has been made in view of such circumstances, and can protect a circuit against a high voltage or an overcurrent that occurs instantaneously, and is a conventional glow-type, rapid-type, or inverter-type fluorescent lamp and LED fluorescent lamp. The present invention provides a high voltage constant current circuit that can correspond to the lighting device of the above.

  In order to solve the above problems, in the high-voltage constant current circuit according to claim 1 of the present invention, a rectifier that converts an alternating current into a direct current, and a current that amplifies the direct current converted by the rectifier The amplifier is composed of a plurality of rectifiers, each of which includes an amplifying unit, a constant current control unit, and a light source, and the rectifying unit is connected in parallel. Since this is a configuration that does not, it is necessary to set a predetermined parameter value in advance.

  Also, in the high voltage constant current circuit according to claim 2 of the present invention, the high voltage constant current circuit according to claim 1 consumes, stores and discharges power generated in the high voltage constant current circuit. As in the high-voltage constant current circuit according to claim 1, since the structure does not require a detector, there is no need to set a prescribed parameter value in advance. Cost.

A high voltage constant current circuit according to a third aspect of the present invention is the high voltage constant current circuit according to the first and second aspects, wherein the current control unit is a constant current diode.
In such a configuration, the constant current diode controls not only the function of the rectification unit and the balance between the current and voltage of the high voltage constant current circuit, but also a ballast in a conventional fluorescent lamp lighting device. It has the effect of concurrently serving as

  In the high voltage constant current circuit of the present invention, not only conventional fluorescent lamps of glow type, rapid type and inverter type, but also LED fluorescent lamps can be used without changing the configuration of the lighting device using the same lighting device. There is an effect that there is no risk of circuit destruction due to a rapid temperature rise of lighting fixture components such as coils and filaments due to overcurrent generated at the end of the life of the fluorescent tube.

  The high-voltage constant-current circuit of the present invention is useful for glow-type, rapid-type, and inverter-type conventional fluorescent lamps and LED fluorescent lamp lighting devices.

It is a conceptual diagram of the electric circuit of this invention.

Claims (5)

In a high voltage constant current circuit comprising a rectifier that converts alternating current into direct current, a current amplifier that amplifies the direct current converted by the rectifier, a constant current controller, and a target device that requires power The high-voltage constant current circuit is characterized in that the rectifier unit includes a plurality of rectifiers connected in parallel, and is configured to control overcurrent generated in a pulsed manner. The high voltage constant current circuit according to claim 1, further comprising a passive element that consumes, stores, and discharges power generated in the high voltage constant current circuit. The high voltage constant current circuit according to claim 1, wherein the current control unit is a constant current diode. 4. A high voltage constant current circuit according to claim 1, wherein a withstand voltage diode is added to the front part of the circuit. The LED lighting fixture which attached the high voltage constant current circuit in any one of Claims 1-4.

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