一种带调光功能的LED均流驱动电路设计  

Design of a current sharing circuit for LED with dimming function

作　　者：程新华[1] 

机构地区：[1]汉中职业技术学院,陕西汉中723000

出　　处：《信息技术》2018年第3期145-149,共5页Information Technology

摘　　要：目前LED调光方式多数采用基于可控硅的脉宽调制方式,这种方式虽然具有调光成本低、与现有线路兼容、无需重新布线等优点,但是也存在调光性能较差,会引起支路导通电流超过LED额定电流,降低LED的工作可靠性等诸多缺陷。针对此问题,文中提出一种带调光功能的均流驱动电路,该电路在常见的脉宽调制LED驱动电路的基础上,引入最小导通电流反馈控制和支路电流闭环控制,能够保证支路导通电流相等且保持在额定电流的85%以下,使得LED电路具有较好的发光效率,同时提高LED的工作可靠性。实验结果表明本文所提出的驱动电路能够高效驱动LED电路,且具有光源稳定、支路均流和精确调光等优点。At present, most ol the LED dimming method based on SCR-based pulse width modulation, this way although the dimming low cost,compatible with the existing c irc u its,without re- w ir in g,but its dimming performance is poor,and wi l l lead to branch current to exceed the LED rated current,reducing the LED l i fe . Aiming at this problem, this paper proposes a pulse width modulation dimming c ircuit based on the minimum on-current feedback control, which introduces the minimum current feedback control and the branch current closed-loop control on the basis of the common pulse width modulation LED driver circuit,it can ensure that the branch conduction current equal and maintain the rated current of 85% or less, making the LED luminous intensity and s ta b i l ity, improve the re lia b i l ity of the use of LED. The experimental results show that the proposed driving c ircu it can drive the LED c ircuit efficiently, and has the advantages of lig h t source s ta b i l ity, branch current sharing and precise dimming.

关 键 词：LED 调光 电流反馈 脉宽调制 均流控制 

分 类 号：TN312.8[电子电信—物理电子学]