Drive circuit for load current of high-power controllable LED

Abstract

The invention belongs to the power supply of an illumination light source, in particular to a drive circuit for the load current of a high-power controllable LED, which is characterized in that a signal sampling circuit, a photoelectric coupling isolation circuit and a protection circuit are electrically connected between a constant-current constant-voltage output circuit and a single-end flybackDC / DC power inverter in series, the signal sampling circuit controls an overcurrent, overvoltage, overtemperature and undervoltage protection circuit by the isolation of the photoelectric coupling isolation circuit after an overcurrent, overvoltage, overtemperature and undervoltage signal is amplified, the output of the single-end flyback DC / DC power inverter is regulated by the overcurrent, overvoltage, overtemperature and undervoltage protection circuit, and the constant-current constant-voltage output circuit outputs stable voltage and current. The invention provides the drive circuit for the load current of the high-power controllable LED, which has high power, high reliability and small change along with the factors of the input voltage, the temperature and the like.

Description

technical field [0001] The invention belongs to a power supply of an illumination light source, in particular to a driving circuit of a high-power controllable LED load current. Background technique [0002] LED is a solid light source. When a forward voltage is applied to both ends of the LED, the minority carriers and majority carriers in the semiconductor recombine, and the excess energy released will cause photon emission. Light-emitting diodes of different colors can be made by using different materials. As a new light source, in recent years, major companies and research institutions have been doing research on LEDs, which has greatly improved their luminous efficiency. Lumiled has developed and produced white LEDs with a luminous efficacy of 90Lm / W, which has reached the level of incandescent lamps. s level. [0003] Compared with incandescent lamps, LEDs have many advantages in terms of performance: [0004] See the table below: [0005] Table 1 Performance compa...

AI Technical Summary

Problems solved by technology

The light output of the LED is directly related to the LED current, so when the input voltage and ambient temperature of the LED drive circuit change, the light output of the LED will change with the input voltage and temperature, and if the LED current Out of control, the long-term operation of the LED under high current will affect the reliability and life of the LED, and may fail

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