YUANNENGJI 由於LED晶片功率低、工作電壓低, a large number of series and parallel connections must be used in the production of lamps to meet the power requirements. How to connect these chips is an issue we must take seriously. 否則, the service life of the lamp will be greatly shortened, resulting in the embarrassing situation of “節能但不省錢”.
作為電子元件, LED有很特別的一面, 這是非線性. 簡單地說, 只要施加在LED上的電壓稍有變化, it will cause a large change in the chip current. 如果處理不當, it will seriously affect the life of the LED. 以下是LED晶片各種連接方式的優缺點:
1. 串聯
串連是LED晶片最合理的連接方式
The basic feature of the series circuit is that the current on all LED chips is equal, so the power difference between each chip is equal to their voltage difference, 並且不會高於它. 因此, the series connection method has the strongest tolerance for the inconsistency of LED chips.
串聯電路的唯一缺點是一旦晶片開路, the entire lamp or the entire string of lights will not light up, and the short circuit has basically no effect. 然而, the proportion of open circuits in chip failures is lower than that of short circuits. 因此, the overall failure rate of series circuits is very low.
如果你想萬無一失, you can connect a 4v~5v voltage regulator in parallel to each chip to provide a path when the chip is open, 但成本會稍高一些. 然而, it is worth it for some special occasions with high requirements.
2. 並聯
並聯是最不確定的連接方式之一 LED 晶片, which will amplify the consequences of LED inconsistency and cause premature damage to the lamps. If you are not sure whether you can purchase chips with highly consistent vF values, 請勿使用並聯連接.
現以3.0ⅴ和3.6ⅴ晶片為例. 並聯後它們的平均vF值將高於 3.0, 導致3.0ⅴ LED電流過大. 隨著溫度升高, vF將進一步下降，功耗將持續增加. 這樣的惡性循環會大大縮短並聯組中低vF值晶片的壽命.
如果這個晶片有短路故障, 整組晶片不會點亮. 如果電源輸出電流很大, 它會很快將這個晶片燒成短路, 然後把本來就該屬於自己的電流分配給別人, 從而加速這組晶片的老化速度.
3. 平行優先, then series connection
平行優先, 那麼串聯就體現了串聯的優點, 但也無法避免並聯的缺點, 所以這不是最好的連接方法. 然而, 這種模式最常用於螢光燈. 例如, 18w螢光燈基本上都是 4 平行和 24 系列.
這種連接方式的前提是一旦晶片打開, 其他晶片可以繼續點亮. 表面上, 影響不大, 但會加速剩餘晶片的損壞速度. 當然, 如果大量購買晶片, it is possible to classify the chips more finely and better ensure the consistency of the chips, 這也是採用這種連接方式的基礎.
4. Series connection first, then parallel connection
首先串行連接, then parallel connection absorbs the advantages of both methods and is a more reasonable LED connection method.
Especially for some small businesses in the form of home workshops, 晶片一致性難以保證, so try to adopt this mode to maximize the service life of the lamps. 先一味模仿所謂的並聯, 那麼大廠的串聯方式就行不通了.
以上簡單介紹了各種LED晶片串並聯連接方式的優缺點. 以我個人的經歷, 設計燈具鋁基板時, 應優先考慮串聯, 先串聯後並聯, 盡量避免先並聯後串聯. 至於全並聯的低壓模式, 如果條件允許, 最好使用DC-DC升壓模組改為串聯.