LED bulb light circuit protected by linear temperature control

Abstract

The invention discloses an LED bulb light circuit protected by linear temperature control. The LED bulb light circuit comprises an LED driving circuit and a temperature protection circuit, wherein the LED driving circuit comprises an overcurrent and overvoltage protection unit, a rectification filtering unit, a switch constant-current unit and an output unit, the temperature protection circuit comprises a negative temperature coefficient thermistor, a reference resistor and a temperature detection and control circuit, the negative temperature coefficient thermistor is arranged on an LED light source, and the output unit is connected with a power supply unit. The LED bulb light circuit has the advantages that the negative temperature coefficient thermistor and the reference resistor are adopted, a first working temperature point is set, no any influence of the negative temperature coefficient thermistor on an LED bulb light is generated when the temperature of the LED light source is lower than the first working temperature point, a resistance value of the negative temperature coefficient thermistor changes to make current change of the LED light source linear when the temperature of the LED light source is equal to or higher than the first working temperature point, the luminous brightness of the LED lights source changes unobviously, thus, a lighting effect cannot be affected, and the LED bulb light is prevented from being overheated.

Description

technical field [0001] The invention relates to an LED bulb lamp, in particular to an LED bulb lamp circuit with linear temperature control protection. Background technique [0002] With the ban on the production and sales of traditional incandescent lamps in most countries, incandescent lamps will gradually withdraw from the market, and LED bulbs have begun to enter the market in large quantities. Due to the small size of the LED bulb lamp, it needs to accommodate the LED light source, driving power, etc. Therefore, on the one hand, the LED light source is relatively concentrated and generates a large amount of heat, which will easily lead to overheating of the LED light source, which will not only attenuate the light emission of the LED light source, but also cause It affects the life of the LED light source, which will affect the life of the LED bulb; on the other hand, the driving power itself will also generate heat, and overheating of the driving power will also affect...

AI Technical Summary

Problems solved by technology

However, since the reduction of the output current of the driving power supply will reduce the brightness of the LED light source, if the control is not good, it will cause the LED bulb light to produce light and dark contrast changes.

[0004] The temperature sensor used in the existing LED bulb lamps changes at any time with the temperature, that is, the output current of the driving power supply will change accordingly if the temperature changes slightly. Therefore, the LED light source and the driving power supply will not be overheated. There will also be changes in the luminous brightness of the LED light source; in addition, some temperature sensors will cause the current of the LED bulb to change suddenly as the temperature changes. For example, when reaching a certain temperature point, the current of the LED bulb suddenly becomes smaller, causing the LED The luminance of the light source changes suddenly, which will affect the lighting effect of the LED bulb lamp

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