Temperature adaptive control circuit for a light emitting diode, lighting and/or signaling apparatus

#The present application relates to the field of lighting and control, and in particular, to a temperature adaptive control circuit for a light emitting diode, a lighting and/or signaling apparatus.

#The light emitting diode (LED), as a light emitting device with low power consumption and high brightness, is applied in various apparatuses such as illumination, decoration, signaling apparatuses more and more widely. It is very crucial to control a current of the LED due to its high heat productivity. In order to ensure the LED to work stably, a complex feedback control loop circuit is typically used. However, such control circuit has a high cost, but single function of controlling current. It is desired to provide a cheap, multi-functional and reliable LED control circuit.

#The present application has an object of providing a temperature adaptive control circuit for a light emitting diode, which can adjust the current of the LED depending on change of conditions, such that the LED can emit a light stably and overheating protection can be provided for the LED. The present application also provides a lighting and/or signaling apparatus having the temperature adaptive control circuit.

#FIG. 1 is a schematic view showing a temperature adaptive control circuit for a light emitting diode according to an embodiment of the present invention;

#FIG. 2 is a schematic view showing a temperature adaptive control circuit for a light emitting diode according to another embodiment of the present invention;

#FIG. 3 is a graph of resistance of a negative temperature coefficient thermistor v.s. temperature in an example;

#The embodiments of the present invention will be further explained below with reference to the figures and examples. Throughout the description, the same or similar reference numbers indicate the same or similar members. The following embodiments along with the figures are only used to explain the general concept of the present invention, instead of being intended to limit the scope of the present invention.

#According to the general inventive concept of the present disclosure, it provides a temperature adaptive control circuit for a light emitting diode, including: a light emitting diode load circuit unit in which one or more light emitting diodes are connected; and a temperature adaptive circuit unit including a positive temperature coefficient thermistor and a negative temperature coefficient thermistor connected in series, wherein the temperature adaptive circuit unit is configured such that current flowing through the one or more light emitting diodes in the light emitting diode load circuit unit is a function of sum of resistance of the positive temperature coefficient thermistor and resistance of the negative temperature coefficient thermistor.

#In addition, for the purpose of explanation, numerous specific details are set forth in the following detailed description to provide a thorough understanding to the embodiments of the present invention. It is obvious, however, that one or more embodiments can also be implemented without these specific details.