{"id":5520,"date":"2024-12-17T10:49:29","date_gmt":"2024-12-17T02:49:29","guid":{"rendered":"https:\/\/bo-qi.com\/?p=5520"},"modified":"2026-01-04T18:23:04","modified_gmt":"2026-01-04T10:23:04","slug":"how-to-control-a-constant-current-led-driver-output-with-pwm","status":"publish","type":"post","link":"https:\/\/bo-qi.com\/vi\/how-to-control-a-constant-current-led-driver-output-with-pwm\/","title":{"rendered":"L\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 \u0111i\u1ec1u khi\u1ec3n \u0111\u1ea7u ra c\u1ee7a b\u1ed9 \u0111i\u1ec1u khi\u1ec3n d\u00f2ng \u0111i\u1ec7n kh\u00f4ng \u0111\u1ed5i LED b\u1eb1ng PWM?"},"content":{"rendered":"<p>Th\u00e1ch th\u1ee9c c\u1ee7a vi\u1ec7c \u0111i\u1ec1u ch\u1ec9nh ch\u00ednh x\u00e1c <a href=\"https:\/\/www.nvcuk.com\/technical-support\/view\/what-is-dimming-11\" title=\"\u0111\u1ed9 s\u00e1ng LED\">\u0111\u1ed9 s\u00e1ng LED<\/a> th\u01b0\u1eddng khi\u1ebfn c\u00e1c k\u1ef9 s\u01b0 ph\u1ea3i v\u1eadt l\u1ed9n v\u1edbi c\u00e1c gi\u1ea3i ph\u00e1p ph\u1ee9c t\u1ea1p. \u0110i\u1ec1u ch\u1ebf \u0111\u1ed9 r\u1ed9ng xung (PWM) \u0111\u01a1n gi\u1ea3n h\u00f3a \u0111i\u1ec1u n\u00e0y b\u1eb1ng c\u00e1ch cho ph\u00e9p \u0111i\u1ec1u khi\u1ec3n \u0111\u1ed9 s\u00e1ng m\u01b0\u1ee3t m\u00e0, ngay c\u1ea3 trong c\u00e1c h\u1ec7 th\u1ed1ng d\u00f2ng \u0111i\u1ec7n kh\u00f4ng \u0111\u1ed5i.<\/p>\n<p><strong>\u0110i\u1ec1u ch\u1ebf \u0111\u1ed9 r\u1ed9ng xung (PWM) \u0111i\u1ec1u khi\u1ec3n b\u1ed9 \u0111i\u1ec1u khi\u1ec3n d\u00f2ng \u0111i\u1ec7n kh\u00f4ng \u0111\u1ed5i LED b\u1eb1ng c\u00e1ch b\u1eadt v\u00e0 t\u1eaft LED nhanh ch\u00f3ng, \u0111i\u1ec1u ch\u1ec9nh d\u00f2ng \u0111i\u1ec7n v\u00e0 \u0111i\u1ec7n \u00e1p trung b\u00ecnh cung c\u1ea5p cho LED m\u00e0 kh\u00f4ng l\u00e0m gi\u00e1n \u0111o\u1ea1n qu\u00e1 tr\u00ecnh \u0111i\u1ec1u ch\u1ec9nh d\u00f2ng \u0111i\u1ec7n kh\u00f4ng \u0111\u1ed5i c\u1ee7a b\u1ed9 \u0111i\u1ec1u khi\u1ec3n.<\/strong><\/p>\n<p>T\u00ecm hi\u1ec3u c\u00e1ch PWM c\u00f3 th\u1ec3 bi\u1ebfn \u0111\u1ed5i vi\u1ec7c \u0111i\u1ec1u khi\u1ec3n LED th\u00f4ng qua h\u01b0\u1edbng d\u1eabn k\u1ef9 thu\u1eadt r\u00f5 r\u00e0ng, v\u00ed d\u1ee5 th\u1ef1c t\u1ebf v\u00e0 m\u1eb9o kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1.<\/p>\n<h2>\u0110i\u1ec1u ch\u1ebf \u0111\u1ed9 r\u1ed9ng xung (PWM) l\u00e0 g\u00ec?<\/h2>\n<p><a href=\"https:\/\/bo-qi.com\/what-is-pwm-dimming-a-beginners-guide-to-dimming\/\" title=\"PWM\">PWM<\/a> l\u00e0 vi\u1ebft t\u1eaft c\u1ee7a \u0110i\u1ec1u ch\u1ebf \u0111\u1ed9 r\u1ed9ng xung, m\u1ed9t k\u1ef9 thu\u1eadt \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng r\u1ed9ng r\u00e3i trong \u0111i\u1ec7n t\u1eed \u0111\u1ec3 \u0111i\u1ec1u khi\u1ec3n vi\u1ec7c cung c\u1ea5p \u0111i\u1ec7n n\u0103ng. N\u00f3 ho\u1ea1t \u0111\u1ed9ng b\u1eb1ng c\u00e1ch thay \u0111\u1ed5i t\u1ef7 l\u1ec7 th\u1eddi gian \"b\u1eadt\" so v\u1edbi th\u1eddi gian \"t\u1eaft\" trong m\u1ed9t chu k\u1ef3, c\u00f2n \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 chu k\u1ef3 nhi\u1ec7m v\u1ee5.<\/p>\n<p><strong>PWM cung c\u1ea5p kh\u1ea3 n\u0103ng \u0111i\u1ec1u khi\u1ec3n ch\u00ednh x\u00e1c c\u00f4ng su\u1ea5t \u0111\u1ea7u ra b\u1eb1ng c\u00e1ch \u0111i\u1ec1u ch\u1ec9nh chu k\u1ef3 nhi\u1ec7m v\u1ee5. \u0110\u1ed1i v\u1edbi LED, \u0111i\u1ec1u n\u00e0y c\u00f3 ngh\u0129a l\u00e0 \u0111i\u1ec1u ch\u1ec9nh \u0111\u1ed9 s\u00e1ng m\u01b0\u1ee3t m\u00e0 v\u00e0 hi\u1ec7u qu\u1ea3 h\u01a1n.<\/strong><\/p>\n<p><img fetchpriority=\"high\" decoding=\"async\" src=\"https:\/\/bo-qi.com\/wp-content\/uploads\/2024\/11\/image-10.png\" alt=\"h\u00ecnh \u1ea3nh 10\" width=\"503\" height=\"174\" class=\"size-full wp-image-5158\" srcset=\"https:\/\/bo-qi.com\/wp-content\/uploads\/2024\/11\/image-10.png 503w, https:\/\/bo-qi.com\/wp-content\/uploads\/2024\/11\/image-10-300x104.png 300w, https:\/\/bo-qi.com\/wp-content\/uploads\/2024\/11\/image-10-18x6.png 18w\" sizes=\"(max-width: 503px) 100vw, 503px\" \/> Chu k\u1ef3 nhi\u1ec7m v\u1ee5<\/p>\n<h3>C\u00e1ch PWM ho\u1ea1t \u0111\u1ed9ng:<\/h3>\n<ul>\n<li><strong>T\u1ea7n s\u1ed1<\/strong>: X\u00e1c \u0111\u1ecbnh t\u1ea7n su\u1ea5t chu k\u1ef3 l\u1eb7p l\u1ea1i m\u1ed7i gi\u00e2y.<\/li>\n<li><strong>Chu k\u1ef3 nhi\u1ec7m v\u1ee5<\/strong>: \u0110\u1ea1i di\u1ec7n cho ph\u1ea7n tr\u0103m th\u1eddi gian t\u00edn hi\u1ec7u duy tr\u00ec tr\u1ea1ng th\u00e1i \"b\u1eadt\" trong m\u1ed7i chu k\u1ef3.<\/li>\n<\/ul>\n<table>\n<thead>\n<tr>\n<th><strong>Chu k\u1ef3 nhi\u1ec7m v\u1ee5 (%)<\/strong><\/th>\n<th><strong>\u0110\u1ed9 s\u00e1ng c\u1ea3m nh\u1eadn<\/strong><\/th>\n<th><strong>M\u00f4 T\u1ea3<\/strong><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>10%<\/td>\n<td>Th\u1ea5p<\/td>\n<td>LED s\u00e1ng m\u1edd.<\/td>\n<\/tr>\n<tr>\n<td>50%<\/td>\n<td>Trung b\u00ecnh<\/td>\n<td>LED \u1edf \u0111\u1ed9 s\u00e1ng m\u1ed9t n\u1eeda.<\/td>\n<\/tr>\n<tr>\n<td>90%<\/td>\n<td>Cao<\/td>\n<td>LED g\u1ea7n nh\u01b0 s\u00e1ng \u0111\u1ea7y \u0111\u1ee7.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>PWM v\u01b0\u1ee3t tr\u1ed9i trong c\u00e1c \u1ee9ng d\u1ee5ng y\u00eau c\u1ea7u hi\u1ec7u qu\u1ea3 n\u0103ng l\u01b0\u1ee3ng v\u00e0 \u0111i\u1ec1u khi\u1ec3n ch\u00ednh x\u00e1c, khi\u1ebfn n\u00f3 tr\u1edf th\u00e0nh l\u1ef1a ch\u1ecdn t\u1ef1 nhi\u00ean cho vi\u1ec7c \u0111i\u1ec1u ch\u1ec9nh \u0111\u1ed9 s\u00e1ng LED.<\/p>\n<h2>PWM \u0111i\u1ec1u khi\u1ec3n b\u1ed9 \u0111i\u1ec1u khi\u1ec3n d\u00f2ng \u0111i\u1ec7n kh\u00f4ng \u0111\u1ed5i LED nh\u01b0 th\u1ebf n\u00e0o?<\/h2>\n<p>PWM t\u01b0\u01a1ng th\u00edch v\u1edbi <a href=\"https:\/\/boqiled.com\/constant-voltage-vs-constant-current-led-drivers-which-one-is-right-for-your-leds\/\" title=\"b\u1ed9 \u0111i\u1ec1u khi\u1ec3n d\u00f2ng \u0111i\u1ec7n kh\u00f4ng \u0111\u1ed5i LED\">b\u1ed9 \u0111i\u1ec1u khi\u1ec3n d\u00f2ng \u0111i\u1ec7n kh\u00f4ng \u0111\u1ed5i LED<\/a>, nh\u01b0ng n\u00f3 ho\u1ea1t \u0111\u1ed9ng kh\u00e1c so v\u1edbi c\u00e1c ph\u01b0\u01a1ng ph\u00e1p \u0111i\u1ec1u ch\u1ec9nh \u0111\u1ed9 s\u00e1ng truy\u1ec1n th\u1ed1ng.<\/p>\n<p><strong>PWM \u0111i\u1ec1u khi\u1ec3n \u0111\u1ed9 s\u00e1ng LED b\u1eb1ng c\u00e1ch s\u1eeda \u0111\u1ed5i d\u00f2ng \u0111i\u1ec7n trung b\u00ecnh th\u00f4ng qua chuy\u1ec3n m\u1ea1ch nhanh, trong khi b\u1ed9 \u0111i\u1ec1u khi\u1ec3n duy tr\u00ec d\u00f2ng \u0111i\u1ec7n \u1ed5n \u0111\u1ecbnh trong c\u00e1c kho\u1ea3ng th\u1eddi gian \"b\u1eadt\".<\/strong><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/bo-qi.com\/wp-content\/uploads\/2024\/12\/PWM-Dimming.gif\" alt=\"\u0111i\u1ec1u ch\u1ec9nh \u0111\u1ed9 s\u00e1ng pwm\" width=\"330\" height=\"200\" class=\"size-full wp-image-5551\" \/> \u0111i\u1ec1u ch\u1ec9nh \u0111\u1ed9 s\u00e1ng pwm<\/p>\n<h3>C\u00e1c b\u01b0\u1edbc ch\u00ednh:<\/h3>\n<ol>\n<li><strong>T\u00edn hi\u1ec7u \u0111\u1ea7u v\u00e0o<\/strong>: M\u1ed9t vi \u0111i\u1ec1u khi\u1ec3n ho\u1eb7c b\u1ed9 t\u1ea1o PWM t\u1ea1o ra t\u00edn hi\u1ec7u t\u1ea7n s\u1ed1 cao.<\/li>\n<li><strong>H\u00e0nh \u0111\u1ed9ng chuy\u1ec3n m\u1ea1ch<\/strong>: B\u1ed9 \u0111i\u1ec1u khi\u1ec3n ph\u1ea3n h\u1ed3i b\u1eb1ng c\u00e1ch b\u1eadt v\u00e0 t\u1eaft LED \u1edf c\u00f9ng t\u1ea7n s\u1ed1.<\/li>\n<li><strong>Ki\u1ec3m so\u00e1t \u0111\u1ed9 s\u00e1ng<\/strong>: \u0110i\u1ec1u ch\u1ec9nh chu k\u1ef3 nhi\u1ec7m v\u1ee5 thay \u0111\u1ed5i c\u00f4ng su\u1ea5t \u00e1nh s\u00e1ng trung b\u00ecnh.<\/li>\n<\/ol>\n<h3>V\u00ed d\u1ee5 v\u1ec1 m\u1ea1ch:<\/h3>\n<p>H\u00e3y t\u01b0\u1edfng t\u01b0\u1ee3ng s\u1eed d\u1ee5ng Arduino \u0111\u1ec3 t\u1ea1o ra <a href=\"https:\/\/www.circuitbread.com\/ee-faq\/what-is-a-pwm-signal\" title=\"t\u00edn hi\u1ec7u PWM\">t\u00edn hi\u1ec7u PWM<\/a> cho m\u1ed9t IC \u0111i\u1ec1u khi\u1ec3n LED. Vi \u0111i\u1ec1u khi\u1ec3n g\u1eedi xung \u0111\u1ebfn \u0111\u1ea7u v\u00e0o \u0111i\u1ec1u ch\u1ec9nh \u0111\u1ed9 s\u00e1ng c\u1ee7a b\u1ed9 \u0111i\u1ec1u khi\u1ec3n, t\u1eeb \u0111\u00f3 \u0111i\u1ec1u ch\u1ec9nh c\u01b0\u1eddng \u0111\u1ed9 \u00e1nh s\u00e1ng t\u01b0\u01a1ng \u1ee9ng.<\/p>\n<hr \/>\n<h2>T\u1ea1i sao n\u00ean s\u1eed d\u1ee5ng PWM \u0111\u1ec3 \u0111i\u1ec1u ch\u1ec9nh \u0111\u1ed9 s\u00e1ng LED?<\/h2>\n<p>Ki\u1ec3m so\u00e1t \u0111\u1ed9 s\u00e1ng r\u1ea5t quan tr\u1ecdng trong nhi\u1ec1u \u1ee9ng d\u1ee5ng chi\u1ebfu s\u00e1ng, v\u00e0 PWM mang l\u1ea1i nh\u1eefng l\u1ee3i th\u1ebf \u0111\u1ed9c \u0111\u00e1o.<\/p>\n<p><strong>PWM cung c\u1ea5p hi\u1ec7u qu\u1ea3 n\u0103ng l\u01b0\u1ee3ng, chuy\u1ec3n \u0111\u1ed5i \u0111\u1ed9 s\u00e1ng m\u01b0\u1ee3t m\u00e0 v\u00e0 kh\u1ea3 n\u0103ng t\u01b0\u01a1ng th\u00edch v\u1edbi nhi\u1ec1u b\u1ed9 \u0111i\u1ec1u khi\u1ec3n LED kh\u00e1c nhau, khi\u1ebfn n\u00f3 tr\u1edf n\u00ean l\u00fd t\u01b0\u1edfng cho c\u00e1c h\u1ec7 th\u1ed1ng chi\u1ebfu s\u00e1ng hi\u1ec7n \u0111\u1ea1i.<\/strong><\/p>\n<h3>L\u1ee3i \u00edch c\u1ee7a PWM:<\/h3>\n<ol>\n<li><strong>Hi\u1ec7u su\u1ea5t n\u0103ng l\u01b0\u1ee3ng<\/strong>: LED ch\u1ec9 ho\u1ea1t \u0111\u1ed9ng trong kho\u1ea3ng th\u1eddi gian \"b\u1eadt\", gi\u1ea3m thi\u1ec3u m\u1ee9c ti\u00eau th\u1ee5 \u0111i\u1ec7n n\u0103ng.<\/li>\n<li><strong>Ki\u1ec3m so\u00e1t \u0111\u1ed9 s\u00e1ng ch\u00ednh x\u00e1c<\/strong>: PWM cho ph\u00e9p \u0111i\u1ec1u ch\u1ec9nh tinh t\u1ebf m\u00e0 kh\u00f4ng c\u00f3 hi\u1ec7n t\u01b0\u1ee3ng nh\u1ea5p nh\u00e1y \u0111\u00e1ng ch\u00fa \u00fd.<\/li>\n<li><strong>Qu\u1ea3n l\u00fd nhi\u1ec7t<\/strong>: B\u1eb1ng c\u00e1ch h\u1ea1n ch\u1ebf cung c\u1ea5p \u0111i\u1ec7n n\u0103ng, PWM gi\u00fap gi\u1eef cho LED m\u00e1t h\u01a1n.<\/li>\n<\/ol>\n<table>\n<thead>\n<tr>\n<th><strong>L\u1ee3i \u00edch<\/strong><\/th>\n<th><strong>M\u00f4 T\u1ea3<\/strong><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Ti\u1ebft ki\u1ec7m n\u0103ng l\u01b0\u1ee3ng<\/td>\n<td>Gi\u1ea3m m\u1ee9c s\u1eed d\u1ee5ng \u0111i\u1ec7n n\u0103ng kh\u00f4ng c\u1ea7n thi\u1ebft.<\/td>\n<\/tr>\n<tr>\n<td>L\u00e0m m\u1edd m\u01b0\u1ee3t m\u00e0<\/td>\n<td>Cung c\u1ea5p thay \u0111\u1ed5i \u0111\u1ed9 s\u00e1ng kh\u00f4ng nh\u1ea5p nh\u00e1y.<\/td>\n<\/tr>\n<tr>\n<td>Tu\u1ed5i th\u1ecd LED d\u00e0i h\u01a1n<\/td>\n<td>Gi\u1ea3m thi\u1ec3u \u1ee9ng su\u1ea5t nhi\u1ec7t.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Nh\u1eefng t\u00ednh n\u0103ng n\u00e0y l\u00e0m cho PWM tr\u1edf n\u00ean thi\u1ebft y\u1ebfu cho c\u00e1c \u1ee9ng d\u1ee5ng trong gia \u0111\u00ecnh, doanh nghi\u1ec7p v\u00e0 m\u00f4i tr\u01b0\u1eddng c\u00f4ng nghi\u1ec7p.<\/p>\n<hr \/>\n<h2>S\u1ef1 kh\u00e1c bi\u1ec7t gi\u1eefa b\u1ed9 \u0111i\u1ec1u khi\u1ec3n LED d\u00f2ng \u0111i\u1ec7n kh\u00f4ng \u0111\u1ed5i v\u00e0 PWM l\u00e0 g\u00ec?<\/h2>\n<p>Hi\u1ec3u \u0111\u01b0\u1ee3c s\u1ef1 kh\u00e1c bi\u1ec7t gi\u1eefa b\u1ed9 \u0111i\u1ec1u khi\u1ec3n d\u00f2ng \u0111i\u1ec7n kh\u00f4ng \u0111\u1ed5i v\u00e0 PWM gi\u00fap b\u1ea1n ch\u1ecdn \u0111\u01b0\u1ee3c gi\u1ea3i ph\u00e1p ph\u00f9 h\u1ee3p v\u1edbi nhu c\u1ea7u c\u1ee7a m\u00ecnh.<\/p>\n<p><strong>B\u1ed9 \u0111i\u1ec1u khi\u1ec3n d\u00f2ng \u0111i\u1ec7n kh\u00f4ng \u0111\u1ed5i cung c\u1ea5p d\u00f2ng \u0111i\u1ec7n \u1ed5n \u0111\u1ecbnh \u0111\u1ec3 c\u00f3 hi\u1ec7u su\u1ea5t nh\u1ea5t qu\u00e1n, trong khi b\u1ed9 \u0111i\u1ec1u khi\u1ec3n PWM \u0111i\u1ec1u ch\u1ec9nh \u0111\u1ed9 s\u00e1ng th\u00f4ng qua chuy\u1ec3n m\u1ea1ch nhanh.<\/strong><\/p>\n<h3>B\u1ea3ng so s\u00e1nh:<\/h3>\n<table>\n<thead>\n<tr>\n<th><strong>T\u00ednh N\u0103ng<\/strong><\/th>\n<th><strong>B\u1ed9 Ngu\u1ed3n D\u00f2ng \u0110i\u1ec7n Kh\u00f4ng \u0110\u1ed5i<\/strong><\/th>\n<th><strong>B\u1ed9 \u0111i\u1ec1u khi\u1ec3n PWM<\/strong><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>\u0110i\u1ec1u ch\u1ec9nh d\u00f2ng \u0111i\u1ec7n<\/td>\n<td>Li\u00ean t\u1ee5c<\/td>\n<td>Xung<\/td>\n<\/tr>\n<tr>\n<td>Ph\u01b0\u01a1ng Ph\u00e1p \u0110i\u1ec1u Ch\u1ec9nh \u0110\u1ed9 S\u00e1ng<\/td>\n<td>\u0110i\u1ec1u ch\u1ec9nh \u0111i\u1ec7n \u00e1p<\/td>\n<td>Ki\u1ec3m so\u00e1t chu k\u1ef3 nhi\u1ec7m v\u1ee5<\/td>\n<\/tr>\n<tr>\n<td>Hi\u1ec7u qu\u1ea3<\/td>\n<td>Trung b\u00ecnh<\/td>\n<td>Cao<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>Nh\u1eefng \u0111i\u1ec3m ch\u00ednh c\u1ea7n c\u00e2n nh\u1eafc:<\/h3>\n<ul>\n<li><strong>D\u00f2ng \u0111i\u1ec7n kh\u00f4ng \u0111\u1ed5i<\/strong>: L\u00fd t\u01b0\u1edfng cho c\u00e1c \u1ee9ng d\u1ee5ng c\u1ea7n \u0111i\u1ec1u ch\u1ec9nh d\u00f2ng \u0111i\u1ec7n ch\u00ednh x\u00e1c.<\/li>\n<li><strong>PWM<\/strong>: T\u1ed1t nh\u1ea5t cho c\u00e1c t\u00ecnh hu\u1ed1ng chi\u1ebfu s\u00e1ng \u0111\u1ed9ng ho\u1eb7c y\u00eau c\u1ea7u \u0111i\u1ec1u ch\u1ec9nh \u0111\u1ed9 s\u00e1ng n\u00e2ng cao.<\/li>\n<\/ul>\n<hr \/>\n<h2>V\u00ed d\u1ee5 th\u1ef1c t\u1ebf: \u0110i\u1ec1u khi\u1ec3n b\u1ed9 \u0111i\u1ec1u khi\u1ec3n LED b\u1eb1ng PWM<\/h2>\n<p>S\u1eed d\u1ee5ng PWM trong c\u00e1c \u1ee9ng d\u1ee5ng th\u1ef1c t\u1ebf r\u1ea5t \u0111\u01a1n gi\u1ea3n v\u1edbi c\u00e1c c\u00f4ng c\u1ee5 nh\u01b0 vi \u0111i\u1ec1u khi\u1ec3n.<\/p>\n<h3>V\u00ed d\u1ee5 1: \u0110i\u1ec1u ch\u1ec9nh \u0111\u1ed9 s\u00e1ng LED d\u1ef1a tr\u00ean Arduino<\/h3>\n<ol>\n<li>K\u1ebft n\u1ed1i b\u1ed9 \u0111i\u1ec1u khi\u1ec3n LED v\u1edbi ch\u00e2n \u0111\u1ea7u ra PWM c\u1ee7a Arduino.<\/li>\n<li>S\u1eed d\u1ee5ng m\u00e3 \u0111\u1ec3 \u0111i\u1ec1u ch\u1ec9nh chu k\u1ef3 nhi\u1ec7m v\u1ee5, thay \u0111\u1ed5i \u0111\u1ed9 s\u00e1ng m\u1ed9t c\u00e1ch linh ho\u1ea1t.<\/li>\n<li>\u0110o k\u1ebft qu\u1ea3 b\u1eb1ng m\u00e1y \u0111o \u00e1nh s\u00e1ng \u0111\u1ec3 x\u00e1c nh\u1eadn chuy\u1ec3n \u0111\u1ed5i m\u01b0\u1ee3t m\u00e0.<\/li>\n<\/ol>\n<p><strong>M\u00e3 \u0111o\u1ea1n m\u00e3 cho Arduino<\/strong>:<\/p>\n<pre><code class=\"language-cpp\">int ledPin = 9; \/\/ PWM pin\nvoid setup() {\n  pinMode(ledPin, OUTPUT);\n}\nvoid loop() {\n  for (int i = 0; i &lt;= 255; i++) {\n    analogWrite(ledPin, i); \/\/ Increase brightness\n    delay(10);\n  }\n  for (int i = 255; i &gt;= 0; i--) {\n    analogWrite(ledPin, i); \/\/ Decrease brightness\n    delay(10);\n  }\n}<\/code><\/pre>\n<h2>V\u00ed d\u1ee5 2: S\u1eed d\u1ee5ng IC PWM chuy\u00ean d\u1ee5ng<\/h2>\n<p>IC PWM chuy\u00ean d\u1ee5ng, ch\u1eb3ng h\u1ea1n nh\u01b0 NE555 ho\u1eb7c IC \u0111i\u1ec1u khi\u1ec3n LED chuy\u00ean d\u1ee5ng nh\u01b0 TL494, c\u00f3 th\u1ec3 x\u1eed l\u00fd c\u00e1c thi\u1ebft l\u1eadp ph\u1ee9c t\u1ea1p h\u01a1n y\u00eau c\u1ea7u c\u00f4ng su\u1ea5t \u0111\u1ea7u ra cao h\u01a1n. C\u00e1c IC n\u00e0y \u0111\u1eb7c bi\u1ec7t hi\u1ec7u qu\u1ea3 cho c\u00e1c \u1ee9ng d\u1ee5ng \u0111\u00f2i h\u1ecfi ki\u1ec3m so\u00e1t ch\u00ednh x\u00e1c \u0111\u1ed9 s\u00e1ng v\u00e0 ph\u00e2n ph\u1ed1i \u0111i\u1ec7n n\u0103ng hi\u1ec7u qu\u1ea3.<\/p>\n<h3>\u01afu \u0111i\u1ec3m c\u1ee7a vi\u1ec7c s\u1eed d\u1ee5ng IC PWM:<\/h3>\n<ul>\n<li><strong>X\u1eed l\u00fd c\u00f4ng su\u1ea5t cao<\/strong>: Ph\u00f9 h\u1ee3p cho c\u00e1c thi\u1ebft l\u1eadp LED d\u00f2ng \u0111i\u1ec7n cao.<\/li>\n<li><strong>\u0110i\u1ec1u Khi\u1ec3n Ch\u00ednh X\u00e1c<\/strong>: C\u00e1c t\u00ednh n\u0103ng n\u00e2ng cao nh\u01b0 \u0111i\u1ec1u ch\u1ec9nh t\u1ea7n s\u1ed1 v\u00e0 tinh ch\u1ec9nh chu k\u1ef3 nhi\u1ec7m v\u1ee5.<\/li>\n<li><strong>T\u00ednh linh ho\u1ea1t<\/strong>: T\u01b0\u01a1ng th\u00edch v\u1edbi nhi\u1ec1u lo\u1ea1i b\u1ed9 \u0111i\u1ec1u khi\u1ec3n LED v\u00e0 \u1ee9ng d\u1ee5ng.<\/li>\n<\/ul>\n<h3>V\u00ed d\u1ee5 v\u1ec1 m\u1ea1ch v\u1edbi NE555:<\/h3>\n<p>\u0110\u00e2y l\u00e0 c\u00e1ch b\u1ea1n c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng NE555 \u0111\u1ec3 t\u1ea1o t\u00edn hi\u1ec7u PWM:<\/p>\n<ol>\n<li>K\u1ebft n\u1ed1i IC v\u1edbi ngu\u1ed3n \u0111i\u1ec7n v\u00e0 c\u1ea5u h\u00ecnh m\u1ea1ch \u1edf ch\u1ebf \u0111\u1ed9 kh\u00f4ng \u1ed5n \u0111\u1ecbnh (astable).<\/li>\n<li>\u0110i\u1ec1u ch\u1ec9nh gi\u00e1 tr\u1ecb \u0111i\u1ec7n tr\u1edf v\u00e0 t\u1ee5 \u0111i\u1ec7n \u0111\u1ec3 thi\u1ebft l\u1eadp t\u1ea7n s\u1ed1 v\u00e0 chu k\u1ef3 nhi\u1ec7m v\u1ee5 mong mu\u1ed1n.<\/li>\n<li>Xu\u1ea5t t\u00edn hi\u1ec7u PWM \u0111\u1ebfn \u0111\u1ea7u v\u00e0o c\u1ee7a b\u1ed9 \u0111i\u1ec1u khi\u1ec3n LED \u0111\u1ec3 \u0111i\u1ec1u ch\u1ec9nh \u0111\u1ed9 s\u00e1ng.<\/li>\n<\/ol>\n<table>\n<thead>\n<tr>\n<th><strong>Th\u00e0nh ph\u1ea7n<\/strong><\/th>\n<th><strong>Gi\u00e1 tr\u1ecb<\/strong><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>\u0110i\u1ec7n tr\u1edf R1<\/td>\n<td>10 k\u03a9<\/td>\n<\/tr>\n<tr>\n<td>\u0110i\u1ec7n tr\u1edf R2<\/td>\n<td>100 k\u03a9<\/td>\n<\/tr>\n<tr>\n<td>T\u1ee5 \u0111i\u1ec7n C<\/td>\n<td>1 \u03bcF<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Ph\u01b0\u01a1ng ph\u00e1p n\u00e0y \u0111\u1ea3m b\u1ea3o t\u1ea1o t\u00edn hi\u1ec7u PWM nh\u1ea5t qu\u00e1n cho nhu c\u1ea7u \u0111i\u1ec1u ch\u1ec9nh \u0111\u1ed9 s\u00e1ng LED c\u1ee7a b\u1ea1n.<\/p>\n<hr \/>\n<h2>Nh\u1eefng th\u00e1ch th\u1ee9c ph\u1ed5 bi\u1ebfn v\u00e0 m\u1eb9o kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1<\/h2>\n<p>Ngay c\u1ea3 v\u1edbi nh\u1eefng \u01b0u \u0111i\u1ec3m c\u1ee7a PWM, c\u00e1c v\u1ea5n \u0111\u1ec1 nh\u01b0 nh\u1ea5p nh\u00e1y v\u00e0 nhi\u1ec5u c\u00f3 th\u1ec3 ph\u00e1t sinh trong qu\u00e1 tr\u00ecnh tri\u1ec3n khai. Nh\u1eefng v\u1ea5n \u0111\u1ec1 n\u00e0y th\u01b0\u1eddng b\u1eaft ngu\u1ed3n t\u1eeb vi\u1ec7c x\u1eed l\u00fd t\u00edn hi\u1ec7u kh\u00f4ng \u0111\u00fang c\u00e1ch ho\u1eb7c gi\u1edbi h\u1ea1n ph\u1ea7n c\u1ee9ng.<\/p>\n<h3>C\u00e1c v\u1ea5n \u0111\u1ec1 ph\u1ed5 bi\u1ebfn:<\/h3>\n<ol>\n<li><strong>Nh\u1ea5p Nh\u00e1y<\/strong>: G\u00e2y ra b\u1edfi t\u00edn hi\u1ec7u PWM t\u1ea7n s\u1ed1 th\u1ea5p, m\u00e0 m\u1eaft ng\u01b0\u1eddi c\u00f3 th\u1ec3 nh\u1eadn bi\u1ebft \u0111\u01b0\u1ee3c.\n<ul>\n<li><strong>Gi\u1ea3i Ph\u00e1p<\/strong>: S\u1eed d\u1ee5ng t\u1ea7n s\u1ed1 PWM tr\u00ean 1 kHz \u0111\u1ec3 tr\u00e1nh nh\u1ea5p nh\u00e1y c\u00f3 th\u1ec3 nh\u00ecn th\u1ea5y.<\/li>\n<\/ul>\n<\/li>\n<li><strong>Nhi\u1ec5u<\/strong>: Ti\u1ebfng \u1ed3n \u0111i\u1ec7n t\u1eeb chuy\u1ec3n m\u1ea1ch nhanh c\u00f3 th\u1ec3 l\u00e0m gi\u00e1n \u0111o\u1ea1n c\u00e1c m\u1ea1ch kh\u00e1c.\n<ul>\n<li><strong>Gi\u1ea3i Ph\u00e1p<\/strong>: L\u1eafp \u0111\u1eb7t t\u1ee5 l\u1ecdc v\u00e0 s\u1eed d\u1ee5ng c\u00e1p \u0111\u01b0\u1ee3c che ch\u1eafn \u0111\u1ec3 gi\u1ea3m nhi\u1ec5u.<\/li>\n<\/ul>\n<\/li>\n<li><strong>\u1ee8ng su\u1ea5t nhi\u1ec7t<\/strong>: LED c\u00f3 th\u1ec3 qu\u00e1 nhi\u1ec7t trong qu\u00e1 tr\u00ecnh ho\u1ea1t \u0111\u1ed9ng k\u00e9o d\u00e0i v\u1edbi chu k\u1ef3 nhi\u1ec7m v\u1ee5 cao.\n<ul>\n<li><strong>Gi\u1ea3i Ph\u00e1p<\/strong>: Tri\u1ec3n khai c\u00e1c c\u01a1 ch\u1ebf l\u00e0m m\u00e1t hi\u1ec7u qu\u1ea3 nh\u01b0 t\u1ea3n nhi\u1ec7t ho\u1eb7c keo t\u1ea3n nhi\u1ec7t.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<h3>B\u1ea3ng x\u1eed l\u00fd s\u1ef1 c\u1ed1:<\/h3>\n<table>\n<thead>\n<tr>\n<th><strong>V\u1ea5n \u0111\u1ec1<\/strong><\/th>\n<th><strong>Nguy\u00ean nh\u00e2n<\/strong><\/th>\n<th><strong>Gi\u1ea3i Ph\u00e1p<\/strong><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Nh\u1ea5p Nh\u00e1y<\/td>\n<td>T\u00edn hi\u1ec7u t\u1ea7n s\u1ed1 th\u1ea5p<\/td>\n<td>T\u0103ng t\u1ea7n s\u1ed1 PWM l\u00ean tr\u00ean 1 kHz<\/td>\n<\/tr>\n<tr>\n<td>Qu\u00e1 nhi\u1ec7t<\/td>\n<td>Chu k\u1ef3 nhi\u1ec7m v\u1ee5 qu\u00e1 m\u1ee9c<\/td>\n<td>S\u1eed d\u1ee5ng c\u00e1c c\u01a1 ch\u1ebf l\u00e0m m\u00e1t ph\u00f9 h\u1ee3p<\/td>\n<\/tr>\n<tr>\n<td>Ti\u1ebfng \u1ed2n<\/td>\n<td>Che ch\u1eafn t\u00edn hi\u1ec7u k\u00e9m<\/td>\n<td>Th\u00eam t\u1ee5 l\u1ecdc v\u00e0 c\u00e1p che ch\u1eafn<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Ch\u1ee7 \u0111\u1ed9ng gi\u1ea3i quy\u1ebft nh\u1eefng th\u00e1ch th\u1ee9c n\u00e0y \u0111\u1ea3m b\u1ea3o ho\u1ea1t \u0111\u1ed9ng \u0111i\u1ec1u ch\u1ec9nh \u0111\u1ed9 s\u00e1ng LED \u0111\u00e1ng tin c\u1eady v\u00e0 hi\u1ec7u qu\u1ea3.<\/p>\n<hr \/>\n<h2>L\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 chuy\u1ec3n \u0111\u1ed5i PWM sang d\u00f2ng \u0111i\u1ec7n kh\u00f4ng \u0111\u1ed5i cho c\u00e1c \u1ee9ng d\u1ee5ng c\u1ee5 th\u1ec3?<\/h2>\n<p>Trong m\u1ed9t s\u1ed1 tr\u01b0\u1eddng h\u1ee3p, vi\u1ec7c chuy\u1ec3n \u0111\u1ed5i PWM sang d\u00f2ng \u0111i\u1ec7n kh\u00f4ng \u0111\u1ed5i l\u00e0 c\u1ea7n thi\u1ebft cho c\u00e1c \u1ee9ng d\u1ee5ng y\u00eau c\u1ea7u \u0111\u1ea7u ra d\u00f2ng \u0111i\u1ec7n \u1ed5n \u0111\u1ecbnh. Vi\u1ec7c chuy\u1ec3n \u0111\u1ed5i n\u00e0y th\u01b0\u1eddng \u0111\u01b0\u1ee3c th\u1ef1c hi\u1ec7n b\u1eb1ng c\u00e1ch s\u1eed d\u1ee5ng b\u1ed9 l\u1ecdc th\u00f4ng th\u1ea5p.<\/p>\n<h3>C\u00e1c b\u01b0\u1edbc chuy\u1ec3n \u0111\u1ed5i:<\/h3>\n<ol>\n<li><strong>Th\u00eam b\u1ed9 l\u1ecdc th\u00f4ng th\u1ea5p<\/strong>: S\u1eed d\u1ee5ng m\u1ea1ch RC (k\u1ebft h\u1ee3p \u0111i\u1ec7n tr\u1edf-t\u1ee5 \u0111i\u1ec7n) \u0111\u1ec3 l\u00e0m m\u1ecbn t\u00edn hi\u1ec7u PWM th\u00e0nh \u0111i\u1ec7n \u00e1p DC \u1ed5n \u0111\u1ecbnh.<\/li>\n<li><strong>C\u1ea5p t\u00edn hi\u1ec7u \u0111\u00e3 l\u1ecdc<\/strong>: K\u1ebft n\u1ed1i \u0111\u1ea7u ra v\u1edbi \u0111\u1ea7u v\u00e0o \u0111i\u1ec1u khi\u1ec3n c\u1ee7a b\u1ed9 \u0111i\u1ec1u khi\u1ec3n d\u00f2ng \u0111i\u1ec7n kh\u00f4ng \u0111\u1ed5i.<\/li>\n<\/ol>\n<h3>V\u00ed d\u1ee5 v\u1ec1 m\u1ea1ch:<\/h3>\n<p>\u0110\u00e2y l\u00e0 c\u1ea5u h\u00ecnh b\u1ed9 l\u1ecdc th\u00f4ng th\u1ea5p RC c\u01a1 b\u1ea3n:<\/p>\n<table>\n<thead>\n<tr>\n<th><strong>Th\u00e0nh ph\u1ea7n<\/strong><\/th>\n<th><strong>Gi\u00e1 tr\u1ecb<\/strong><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>\u0110i\u1ec7n tr\u1edf (R)<\/td>\n<td>10 k\u03a9<\/td>\n<\/tr>\n<tr>\n<td>T\u1ee5 \u0111i\u1ec7n (C)<\/td>\n<td>10 \u03bcF<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Thi\u1ebft l\u1eadp n\u00e0y \u0111\u1ea3m b\u1ea3o t\u00edn hi\u1ec7u PWM \u0111\u01b0\u1ee3c chuy\u1ec3n \u0111\u1ed5i th\u00e0nh \u0111i\u1ec7n \u00e1p m\u01b0\u1ee3t m\u00e0 ph\u00f9 h\u1ee3p \u0111\u1ec3 \u0111i\u1ec1u khi\u1ec3n c\u00e1c b\u1ed9 \u0111i\u1ec1u khi\u1ec3n d\u00f2ng \u0111i\u1ec7n kh\u00f4ng \u0111\u1ed5i. <\/p>\n<h3>C\u00e1c t\u00ecnh hu\u1ed1ng \u1ee9ng d\u1ee5ng:<\/h3>\n<ul>\n<li>H\u1ec7 th\u1ed1ng chi\u1ebfu s\u00e1ng c\u00f4ng nghi\u1ec7p \u0111\u1ed9 ch\u00ednh x\u00e1c cao.<\/li>\n<li>Thi\u1ebft l\u1eadp LED y\u00eau c\u1ea7u d\u00f2ng \u0111i\u1ec7n \u1ed5n \u0111\u1ecbnh \u0111\u1ec3 c\u00f3 \u0111\u1ed9 s\u00e1ng \u0111\u1ed3ng \u0111\u1ec1u.<\/li>\n<\/ul>\n<p>B\u1eb1ng c\u00e1ch s\u1eed d\u1ee5ng k\u1ef9 thu\u1eadt n\u00e0y, t\u00edn hi\u1ec7u PWM c\u00f3 th\u1ec3 th\u00edch \u1ee9ng v\u1edbi nhi\u1ec1u lo\u1ea1i b\u1ed9 \u0111i\u1ec1u khi\u1ec3n LED h\u01a1n.<\/p>\n<hr \/>\n<h2>Ph\u1ea7n k\u1ebft lu\u1eadn<\/h2>\n<p>PWM c\u00e1ch m\u1ea1ng h\u00f3a vi\u1ec7c \u0111i\u1ec1u ch\u1ec9nh \u0111\u1ed9 s\u00e1ng LED b\u1eb1ng c\u00e1ch k\u1ebft h\u1ee3p \u0111\u1ed9 ch\u00ednh x\u00e1c, hi\u1ec7u qu\u1ea3 n\u0103ng l\u01b0\u1ee3ng v\u00e0 kh\u1ea3 n\u0103ng t\u01b0\u01a1ng th\u00edch r\u1ed9ng r\u00e3i. T\u1eeb c\u00e1c thi\u1ebft l\u1eadp c\u01a1 b\u1ea3n s\u1eed d\u1ee5ng vi \u0111i\u1ec1u khi\u1ec3n \u0111\u1ebfn c\u00e1c m\u1ea1ch ti\u00ean ti\u1ebfn v\u1edbi IC chuy\u00ean d\u1ee5ng, PWM cung c\u1ea5p c\u00e1c gi\u1ea3i ph\u00e1p linh ho\u1ea1t cho k\u1ef9 s\u01b0. Gi\u1ea3i quy\u1ebft c\u00e1c th\u00e1ch th\u1ee9c ph\u1ed5 bi\u1ebfn v\u00e0 t\u1eadn d\u1ee5ng c\u00e1c k\u1ef9 thu\u1eadt chuy\u1ec3n \u0111\u1ed5i \u0111\u1ea3m b\u1ea3o hi\u1ec7u su\u1ea5t \u1ed5n \u0111\u1ecbnh v\u00e0 hi\u1ec7u qu\u1ea3. Th\u1eed nghi\u1ec7m v\u1edbi PWM \u0111\u1ec3 kh\u00e1m ph\u00e1 to\u00e0n b\u1ed9 ti\u1ec1m n\u0103ng c\u1ee7a n\u00f3 trong c\u00e1c \u1ee9ng d\u1ee5ng LED c\u1ee7a b\u1ea1n!<\/p>","protected":false},"excerpt":{"rendered":"<p>The challenge of precise LED dimming often leaves engineers grappling with complex solutions. Pulse Width Modulation (PWM) simplifies this by enabling smooth control over brightness, even in constant current systems. Pulse Width Modulation (PWM) controls a constant current LED driver by rapidly switching the LED on and off, adjusting the average current and voltage delivered [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":5550,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_seopress_titles_title":"","_seopress_titles_desc":"","_seopress_robots_index":"","_seopress_robots_follow":"","_seopress_robots_imageindex":"","_seopress_robots_snippet":"","_seopress_robots_primary_cat":"none","_seopress_robots_breadcrumbs":"","_seopress_robots_freeze_modified_date":"","_seopress_robots_custom_modified_date":"","_seopress_robots_canonical":"","_seopress_social_fb_title":"","_seopress_social_fb_desc":"","_seopress_social_fb_img":"","_seopress_social_fb_img_attachment_id":0,"_seopress_social_fb_img_width":0,"_seopress_social_fb_img_height":0,"_seopress_social_twitter_title":"","_seopress_social_twitter_desc":"","_seopress_social_twitter_img":"","_seopress_social_twitter_img_attachment_id":0,"_seopress_social_twitter_img_width":0,"_seopress_social_twitter_img_height":0,"_seopress_redirections_value":"","_seopress_redirections_enabled":"","_seopress_redirections_enabled_regex":"","_seopress_redirections_logged_status":"both","_seopress_redirections_param":"","_seopress_redirections_type":301,"_seopress_analysis_target_kw":"","_seopress_news_disabled":"","_seopress_video_disabled":"","_seopress_video":[],"_seopress_pro_schemas_manual":[],"_seopress_pro_rich_snippets_disable_all":"","_seopress_pro_rich_snippets_disable":[],"_seopress_pro_schemas":[],"footnotes":""},"categories":[36],"tags":[],"class_list":{"0":"post-5520","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-led-driver"},"_links":{"self":[{"href":"https:\/\/bo-qi.com\/vi\/wp-json\/wp\/v2\/posts\/5520","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/bo-qi.com\/vi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/bo-qi.com\/vi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/bo-qi.com\/vi\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/bo-qi.com\/vi\/wp-json\/wp\/v2\/comments?post=5520"}],"version-history":[{"count":0,"href":"https:\/\/bo-qi.com\/vi\/wp-json\/wp\/v2\/posts\/5520\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/bo-qi.com\/vi\/wp-json\/wp\/v2\/media\/5550"}],"wp:attachment":[{"href":"https:\/\/bo-qi.com\/vi\/wp-json\/wp\/v2\/media?parent=5520"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bo-qi.com\/vi\/wp-json\/wp\/v2\/categories?post=5520"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bo-qi.com\/vi\/wp-json\/wp\/v2\/tags?post=5520"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}