Current limiting element and light emitting diode device

Abstract

The invention discloses a current-limiting element and an LED device. The LED device comprises an LED assembly and a current-limiting element, wherein the LED assembly comprises at least one LED which corresponds to a current-limiting resistance value; the current-limiting element comprises a plurality of positive temperature coefficient elements which are connected in series; the plurality of positive temperature coefficient elements have the function of effectively sensing the temperature of the LED and are electrically connected to the LED assembly in series; the current-limiting element has the characteristics of increasing the resistance value of the current-limiting element with the increase of the sensed temperature; the resistance value of the current-limiting element approaches or is equal to the current-limiting resistance value when the LED works at the normal temperature, and when the temperature of the LED rises to an abnormal temperature, the current allowed to pass through by the current-limiting element is reduced gradually till the current is lower than the working current of the light-emitting diode. With adoption of the current-limiting element and the LED device, the condition of high temperature of the LED can be effectively avoided, the LED is prevented from being burnt, and the service life of the LED is prolonged.

Description

technical field

[0001] The present invention relates to a current limiting element and a light emitting diode (Light Emitting Diode; LED) device comprising the current limiting element. The current limiting element adopts a plurality of positive temperature coefficient (PositiveTemperatureCoefficient; PTC) elements, and when it is applied in series with LEDs, it has the effect of real-time current adjustment. Background technique

[0002] The basic properties of LEDs are similar to those of diodes. They have the characteristics that forward bias can pass current, and reverse bias can cut off current. The only difference is that light will be emitted when current flows, and the general forward conduction working voltage is higher than the 0.7V of ordinary diodes. The working voltage of the forward conduction will not change with the magnitude of the current, so the LED cannot be directly applied to both ends of the power supply higher than the working voltage of the forward ...

Examples

Embodiment Construction

[0024] In order to make the above-mentioned and other technical content, features and advantages of the present invention more obvious and understandable, the following specifically cites relevant embodiments, together with the attached drawings, for detailed description as follows:

[0025] Since the resistance of conductive composite materials with positive temperature coefficient (PositiveTemperatureCoefficient; PTC) characteristics responds sensitively to temperature changes, it can be used as a material for current sensing elements and has been widely used in overcurrent protection elements or circuit elements. When an over-current or over-temperature phenomenon occurs in a circuit or battery, its resistance value will instantly increase to a high resistance state (at least 102Ω), and the excess current will be reduced. The temperature corresponding to the instantaneous rise of the resistance is called the trigger critical temperature. Before the trigger critical temperatu...

technical field

[0001] The present invention relates to a current limiting element and a light emitting diode (Light Emitting Diode; LED) device comprising the current limiting element. The current limiting element adopts a plurality of positive temperature coefficient (PositiveTemperatureCoefficient; PTC) elements, and when it is applied in series with LEDs, it has the effect of real-time current adjustment. Background technique

[0002] The basic properties of LEDs are similar to those of diodes. They have the characteristics that forward bias can pass current, and reverse bias can cut off current. The only difference is that light will be emitted when current flows, and the general forward conduction working voltage is higher than the 0.7V of ordinary diodes. The working voltage of the forward conduction will not change with the magnitude of the current, so the LED cannot be directly applied to both ends of the power supply higher than the working voltage of the forward ...

Examples

Embodiment Construction

[0024] In order to make the above-mentioned and other technical content, features and advantages of the present invention more obvious and understandable, the following specifically cites relevant embodiments, together with the attached drawings, for detailed description as follows:

[0025] Since the resistance of conductive composite materials with positive temperature coefficient (PositiveTemperatureCoefficient; PTC) characteristics responds sensitively to temperature changes, it can be used as a material for current sensing elements and has been widely used in overcurrent protection elements or circuit elements. When an over-current or over-temperature phenomenon occurs in a circuit or battery, its resistance value will instantly increase to a high resistance state (at least 102Ω), and the excess current will be reduced. The temperature corresponding to the instantaneous rise of the resistance is called the trigger critical temperature. Before the trigger critical temperatu...

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