{"id":1655,"date":"2025-05-29T03:42:14","date_gmt":"2025-05-29T03:42:14","guid":{"rendered":"https:\/\/nbaem.com\/?p=1655"},"modified":"2025-05-29T03:42:14","modified_gmt":"2025-05-29T03:42:14","slug":"what-is-permanent-magnet","status":"publish","type":"post","link":"https:\/\/nbaem.com\/vi\/what-is-permanent-magnet\/","title":{"rendered":"Nam ch\u00e2m v\u0129nh c\u1eedu l\u00e0 g\u00ec?"},"content":{"rendered":"

H\u1ec7 \u0110magnam V\u0129nh C\u1eedu l\u00e0 g\u00ec?<\/h1>\n

Nam ch\u00e2m xung quanh ch\u00fang ta, nh\u01b0ng b\u1ea1n \u0111\u00e3 bao gi\u1edd d\u1eebng l\u1ea1i \u0111\u1ec3 ngh\u0129 v\u1ec1 \u0111i\u1ec1u g\u00ec l\u00e0m cho m\u1ed9t nam ch\u00e2m tr\u1edf th\u00e0nh \u201cv\u0129nh c\u1eedu\u201d ch\u01b0a? H\u00e3y ph\u00e2n t\u00edch nh\u00e9.<\/p>\n

M\u1ed9t nam ch\u00e2m v\u0129nh c\u1eedu \u0111\u01b0\u1ee3c l\u00e0m t\u1eeb m\u1ed9t v\u1eadt li\u1ec7u \u0111\u00e3 \u0111\u01b0\u1ee3c t\u1eeb h\u00f3a v\u00e0 c\u00f3 th\u1ec3 gi\u1eef tr\u01b0\u1eddng t\u1eeb c\u1ee7a n\u00f3 m\u00e0 kh\u00f4ng c\u1ea7n \u0111i\u1ec7n ho\u1eb7c ngu\u1ed3n n\u0103ng l\u01b0\u1ee3ng kh\u00e1c.<\/strong><\/p>\n

Nam ch\u00e2m \u0111\u00f3ng vai tr\u00f2 trong m\u1ecdi th\u1ee9 t\u1eeb \u0111\u1ed9ng c\u01a1 \u0111\u1ebfn c\u1ea3m bi\u1ebfn, v\u00e0 hi\u1ec3u c\u00e1ch ch\u00fang ho\u1ea1t \u0111\u1ed9ng c\u00f3 th\u1ec3 gi\u00fap b\u1ea1n ch\u1ecdn \u0111\u00fang lo\u1ea1i cho d\u1ef1 \u00e1n ti\u1ebfp theo c\u1ee7a m\u00ecnh.<\/p>\n

 <\/p>\n

V\u1eadt li\u1ec7u n\u00e0o l\u00e0 nam ch\u00e2m v\u0129nh c\u1eedu?<\/h2>\n

Nam ch\u00e2m c\u00f3 v\u1ebb nh\u01b0 l\u00e0 ph\u00e9p thu\u1eadt, nh\u01b0ng ch\u00fang \u0111\u01b0\u1ee3c l\u00e0m t\u1eeb c\u00e1c v\u1eadt li\u1ec7u th\u1ef1c s\u1ef1 v\u1edbi c\u00e1c \u0111\u1eb7c t\u00ednh \u0111\u1ed9c \u0111\u00e1o.<\/p>\n

Nam ch\u00e2m v\u0129nh c\u1eedu th\u01b0\u1eddng \u0111\u01b0\u1ee3c l\u00e0m t\u1eeb neodymium, samarium cobalt, alnico ho\u1eb7c ferrite, m\u1ed7i lo\u1ea1i \u0111\u1ec1u c\u00f3 \u0111\u1eb7c \u0111i\u1ec3m hi\u1ec7u su\u1ea5t ri\u00eang bi\u1ec7t.<\/strong><\/p>\n

 <\/p>\n

Ch\u1ecdn v\u1eadt li\u1ec7u t\u1eeb ph\u00f9 h\u1ee3p<\/h3>\n

C\u00e1c lo\u1ea1i nam ch\u00e2m v\u0129nh c\u1eedu kh\u00e1c nhau \u0111\u01b0\u1ee3c thi\u1ebft k\u1ebf cho c\u00e1c nhu c\u1ea7u c\u1ee5 th\u1ec3. V\u00ed d\u1ee5:<\/p>\n\n\n\n\n\n\n\n\n
V\u1eadt li\u1ec7u<\/th>\nThu\u1ed9c t\u00ednh<\/th>\n\u1ee8ng d\u1ee5ng \u0111i\u1ec3n h\u00ecnh<\/th>\n<\/tr>\n<\/thead>\n
Neodymium (NdFeB)<\/strong><\/span><\/a><\/td>\nC\u01b0\u1eddng \u0111\u1ed9 cao, \u1ed5n \u0111\u1ecbnh nhi\u1ec7t th\u1ea5p, d\u1ec5 b\u1ecb g\u1ec9<\/td>\n\u0110\u1ed9ng c\u01a1 hi\u1ec7u su\u1ea5t cao, \u0111i\u1ec7n t\u1eed<\/td>\n<\/tr>\n
Samari C\u00f4ban<\/strong><\/span><\/a><\/td>\nC\u01b0\u1eddng \u0111\u1ed9 t\u1ed1t, \u1ed5n \u0111\u1ecbnh nhi\u1ec7t cao, ch\u1ed1ng \u0103n m\u00f2n<\/td>\nH\u00e0ng kh\u00f4ng v\u0169 tr\u1ee5, thi\u1ebft b\u1ecb y t\u1ebf<\/td>\n<\/tr>\n
Alnico<\/span><\/strong><\/a><\/td>\nCh\u1ecbu nhi\u1ec7t cao, c\u01b0\u1eddng \u0111\u1ed9 trung b\u00ecnh<\/td>\nC\u1ea3m bi\u1ebfn, b\u1ed9 thu guitar<\/td>\n<\/tr>\n
Ferrite (G\u1ed1m)<\/a><\/span><\/strong><\/td>\nGi\u00e1 th\u00e0nh r\u1ebb, ch\u1ed1ng \u0103n m\u00f2n, c\u01b0\u1eddng \u0111\u1ed9 th\u1ea5p<\/td>\nLoa, nam ch\u00e2m t\u1ee7 l\u1ea1nh<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Theo kinh nghi\u1ec7m c\u1ee7a t\u00f4i, nhi\u1ec1u kh\u00e1ch h\u00e0ng ban \u0111\u1ea7u y\u00eau c\u1ea7u nam ch\u00e2m neodymium v\u00ec l\u1ef1c h\u00fat m\u1ea1nh c\u1ee7a ch\u00fang. Tuy nhi\u00ean, sau khi hi\u1ec3u r\u00f5 v\u1ec1 nhi\u1ec7t \u0111\u1ed9 v\u00e0 m\u00f4i tr\u01b0\u1eddng \u1ee9ng d\u1ee5ng, ch\u00fang t\u00f4i th\u01b0\u1eddng chuy\u1ec3n sang samarium cobalt \u0111\u1ec3 ch\u1ecbu nhi\u1ec7t cao ho\u1eb7c ferrite \u0111\u1ec3 ti\u1ebft ki\u1ec7m chi ph\u00ed.<\/p>\n

 <\/p>\n

L\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 bi\u1ebft m\u1ed9t nam ch\u00e2m c\u00f3 ph\u1ea3i l\u00e0 v\u0129nh c\u1eedu kh\u00f4ng?<\/h2>\n

C\u00f3 th\u1ec3 kh\u00e1 kh\u00f3 \u0111\u1ec3 nh\u1eadn bi\u1ebft, nh\u01b0ng c\u00f3 m\u1ed9t s\u1ed1 d\u1ea5u hi\u1ec7u d\u1ec5 nh\u1eadn th\u1ea5y.<\/p>\n

Nam ch\u00e2m v\u0129nh c\u1eedu l\u00e0 khi n\u00f3 c\u00f3 th\u1ec3 h\u00fat c\u00e1c v\u1eadt li\u1ec7u ferromagnetic v\u00e0 gi\u1eef t\u1eeb t\u00ednh ngay c\u1ea3 khi kh\u00f4ng c\u00f3 ngu\u1ed3n \u0111i\u1ec7n b\u00ean ngo\u00e0i.<\/strong><\/p>\n

 <\/p>\n

Ki\u1ec3m tra t\u00ednh v\u0129nh c\u1eedu<\/h3>\n

D\u01b0\u1edbi \u0111\u00e2y l\u00e0 m\u1ed9t s\u1ed1 ph\u01b0\u01a1ng ph\u00e1p t\u00f4i s\u1eed d\u1ee5ng khi \u0111\u00e1nh gi\u00e1 xem m\u1ed9t nam ch\u00e2m c\u00f3 ph\u1ea3i l\u00e0 v\u0129nh c\u1eedu hay kh\u00f4ng:<\/p>\n

1. Quan s\u00e1t h\u00e0nh vi c\u1ee7a n\u00f3<\/strong><\/h4>\n

N\u1ebfu m\u1ed9t nam ch\u00e2m c\u00f3 th\u1ec3 gi\u1eef ghim gi\u1ea5y ho\u1eb7c h\u00fat m\u1ed9t chi\u1ebfc \u0111inh, c\u00f3 kh\u1ea3 n\u0103ng n\u00f3 c\u00f3 tr\u01b0\u1eddng t\u1eeb v\u0129nh c\u1eedu.<\/p>\n

2. Ki\u1ec3m tra ngu\u1ed3n \u0111i\u1ec7n b\u00ean ngo\u00e0i<\/strong><\/h4>\n

Nam ch\u00e2m t\u1ea1m th\u1eddi c\u1ea7n \u0111i\u1ec7n ho\u1eb7c tr\u01b0\u1eddng b\u00ean ngo\u00e0i \u0111\u1ec3 duy tr\u00ec t\u1eeb t\u00ednh. Nam ch\u00e2m v\u0129nh c\u1eedu th\u00ec kh\u00f4ng. Ng\u1eaft ngu\u1ed3n thi\u1ebft b\u1ecb, n\u1ebfu nam ch\u00e2m v\u1eabn ho\u1ea1t \u0111\u1ed9ng, \u0111\u00f3 l\u00e0 nam ch\u00e2m v\u0129nh c\u1eedu.<\/p>\n

3. Xem x\u00e9t v\u1eadt li\u1ec7u<\/strong><\/h4>\n
    \n
  • Neodymium v\u00e0 Samarium Cobalt<\/strong>: Lu\u00f4n l\u00e0 v\u0129nh c\u1eedu.<\/li>\n
  • Nam ch\u00e2m \u0111i\u1ec7n<\/strong>: Ch\u1ec9 t\u1eeb khi c\u00f3 ngu\u1ed3n \u0111i\u1ec7n.<\/li>\n<\/ul>\n

    4. H\u1ecfi nh\u00e0 cung c\u1ea5p<\/strong><\/h4>\n

    Trong c\u00f4ng vi\u1ec7c c\u1ee7a t\u00f4i, ch\u00fang t\u00f4i lu\u00f4n ghi nh\u00e3n nam ch\u00e2m theo lo\u1ea1i c\u1ee7a ch\u00fang. N\u1ebfu kh\u00e1ch h\u00e0ng kh\u00f4ng ch\u1eafc ch\u1eafn, ch\u00fang t\u00f4i ki\u1ec3m tra th\u00f4ng s\u1ed1 v\u1eadt li\u1ec7u v\u00e0 ph\u01b0\u01a1ng ph\u00e1p t\u1eeb h\u00f3a.<\/p>\n

    D\u01b0\u1edbi \u0111\u00e2y l\u00e0 m\u1ed9t so s\u00e1nh:<\/p>\n\n\n\n\n\n\n\n
    \u0110\u1eb7c \u0111i\u1ec3m<\/th>\nNam ch\u00e2m v\u0129nh c\u1eedu<\/th>\nNam ch\u00e2m t\u1ea1m th\u1eddi<\/th>\n<\/tr>\n<\/thead>\n
    C\u1ea7n ngu\u1ed3n \u0111i\u1ec7n kh\u00f4ng?<\/td>\nNo<\/td>\nC\u00f3<\/td>\n<\/tr>\n
    V\u1eadt li\u1ec7u<\/td>\nNdFeB, SmCo, Alnico, Ferrit<\/td>\nS\u1eaft m\u1ec1m, cu\u1ed9n d\u00e2y<\/td>\n<\/tr>\n
    Th\u1eddi gian t\u1eeb tr\u01b0\u1eddng duy tr\u00ec<\/td>\nD\u00e0i h\u1ea1n<\/td>\nNg\u1eafn h\u1ea1n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    M\u1ed9t kh\u00e1ch h\u00e0ng \u1edf Vi\u1ec7t Nam t\u1eebng g\u1ecdi t\u00f4i v\u1ec1 m\u1ed9t chi\u1ebfc nam ch\u00e2m \u201ch\u1ecfng\u201d trong m\u1ed9t \u0111\u1ed9ng c\u01a1. Sau m\u1ed9t cu\u1ed9c tr\u00f2 chuy\u1ec7n nhanh, ch\u00fang t\u00f4i nh\u1eadn ra h\u1ecd \u0111ang th\u1eed nghi\u1ec7m m\u1ed9t nam ch\u00e2m \u0111i\u1ec7n kh\u00f4ng c\u00f3 ngu\u1ed3n \u0111i\u1ec7n. Chuy\u1ec3n sang d\u00f9ng nam ch\u00e2m v\u0129nh c\u1eedu \u0111\u00e3 gi\u1ea3i quy\u1ebft v\u1ea5n \u0111\u1ec1!<\/p>\n

    K\u1ebft lu\u1eadn<\/h2>\n

    Nam ch\u00e2m v\u0129nh c\u1eedu l\u00e0 nh\u1eefng anh h\u00f9ng th\u1ea7m l\u1eb7ng c\u1ee7a c\u00f4ng ngh\u1ec7 hi\u1ec7n \u0111\u1ea1i, cung c\u1ea5p tr\u01b0\u1eddng t\u1eeb \u1ed5n \u0111\u1ecbnh m\u00e0 kh\u00f4ng c\u1ea7n ngu\u1ed3n \u0111i\u1ec7n. T\u1eeb c\u00e1c thi\u1ebft b\u1ecb gia d\u1ee5ng \u0111\u1ebfn c\u00f4ng ngh\u1ec7 kh\u00f4ng gian, ch\u00fang xu\u1ea5t hi\u1ec7n kh\u1eafp n\u01a1i.<\/p>","protected":false},"excerpt":{"rendered":"

    Nam ch\u00e2m v\u0129nh c\u1eedu l\u00e0 g\u00ec? Nam ch\u00e2m c\u00f3 m\u1eb7t kh\u1eafp n\u01a1i quanh ch\u00fang ta, nh\u01b0ng b\u1ea1n \u0111\u00e3 t\u1eebng d\u1eebng l\u1ea1i \u0111\u1ec3 suy ngh\u0129 v\u1ec1 \u0111i\u1ec1u g\u00ec khi\u1ebfn m\u1ed9t nam ch\u00e2m tr\u1edf th\u00e0nh \u201cv\u0129nh c\u1eedu\u201d ch\u01b0a? H\u00e3y ph\u00e2n t\u00edch r\u00f5 h\u01a1n. M\u1ed9t nam ch\u00e2m v\u0129nh c\u1eedu \u0111\u01b0\u1ee3c l\u00e0m t\u1eeb m\u1ed9t v\u1eadt li\u1ec7u \u0111\u00e3 qua qu\u00e1 tr\u00ecnh t\u1eeb t\u00ednh v\u00e0 c\u00f3 th\u1ec3 gi\u1eef \u0111\u01b0\u1ee3c tr\u01b0\u1eddng t\u1eeb c\u1ee7a n\u00f3 m\u00e0 kh\u00f4ng c\u1ea7n \u0111i\u1ec7n ho\u1eb7c ngu\u1ed3n n\u0103ng l\u01b0\u1ee3ng kh\u00e1c.<\/p>","protected":false},"author":1,"featured_media":498,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_mi_skip_tracking":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1655","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized"],"jetpack_featured_media_url":"https:\/\/nbaem.com\/wp-content\/uploads\/2022\/06\/SmCo-magnet-\u603b\u56fe.png","_links":{"self":[{"href":"https:\/\/nbaem.com\/vi\/wp-json\/wp\/v2\/posts\/1655","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nbaem.com\/vi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nbaem.com\/vi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nbaem.com\/vi\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/nbaem.com\/vi\/wp-json\/wp\/v2\/comments?post=1655"}],"version-history":[{"count":2,"href":"https:\/\/nbaem.com\/vi\/wp-json\/wp\/v2\/posts\/1655\/revisions"}],"predecessor-version":[{"id":1657,"href":"https:\/\/nbaem.com\/vi\/wp-json\/wp\/v2\/posts\/1655\/revisions\/1657"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nbaem.com\/vi\/wp-json\/wp\/v2\/media\/498"}],"wp:attachment":[{"href":"https:\/\/nbaem.com\/vi\/wp-json\/wp\/v2\/media?parent=1655"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nbaem.com\/vi\/wp-json\/wp\/v2\/categories?post=1655"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nbaem.com\/vi\/wp-json\/wp\/v2\/tags?post=1655"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}