LED driving loop

Abstract

The invention provides an LED driving loop. The driving loop can work under a low voltage and is not be affected by various interferences caused by installing place and the surrounding environment; the driving loop has small driving current and can stably work when the temperature is changed and can adjust the glaze. The driving loop for LED is characterized by comprising a driving part (for providing power and driving one or a plurality of LED arrays Ln formed by serially connecting one or more LEDs) and a control part, wherein the control part comprises a resistor Rs1 and Rs2 and a temperature correction mechanism part which includes a transistor Tc; the collector of the transistor and the base electrode are connected with an Rc2; the base electrode and the emitter are connected with an Rc1; through adjusting the ratio of the Rc1 and R2, the transistor Tc is combined with one part and the thermal combining degree is adjusted; the temperature of the driving loop is set to an expected property.

Description

technical field [0001] The invention relates to an LED driving circuit and an LED lighting device using the driving circuit. Background technique [0002] With the emergence of white-like LEDs and the improvement of luminous efficiency due to technological progress, lighting sources using LEDs can improve energy efficiency more than the light sources of incandescent lamps commonly used in the past. Now it is commercialized for small and thin LED lighting devices. A lot to try. However, LEDs are different from conventional light sources represented by incandescent lamps. Because they are semiconductors, in order to suppress the temperature rise during operation, the current passing through the LED must not only be sufficient, but also be stable when the temperature and voltage fluctuate. The current value should be set within the rated range. In order to feature the high efficiency of LED, the efficiency must be higher than that of conventional lighting. Therefore, while im...

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Problems solved by technology

However, in this method, the difference in the voltage between the base and the emitter of each transistor used for driving and the emitter resistance will cause an error (such an error must exist), because the base of each transistor used is are connected to each other, so the base potential of the transistor is determined by the lowest potential among them. The lowest potential value is: the potential between the base and the emitter + the emitter resistance × the minimum value of the value calculated by the emitter current value →, so As a result, the drive current of each column of LEDs is different, and the luminance is also different. When a drive transistor breaks down or an LED column is disconnected, it will affect the drive current value of the entire LED, making the luminance of the entire LED and it is difficult to adjust the luminance of lighting fixtures in a large scale

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