how-should-you-size-resistors-for-diodes-and-leds, how-should-you-size-resistors-for-diodes-and-leds, /news
EN
2026/09/23
Te whakamātautau i ngā rēsita mō ngā diode me ngā led he pūkenga matua i te whakamārama i ngā hāngai me te whakamahi i ngā rārangi. Ahakoa he rārangi māmā noa tēnei hei tohu, he rārangi pūmau tonu pea, ko te uara o te rēsita e whāia ana ngā āhua o te oranga o ngā wāhi, te mātātoko o te mātātoko, me te whai pūmau o te rārangi katoa. Mēnā he rēsita hē te whakamātautau, ka rere mai ngā hāngai, ka hāngai te hiko, i te rere o te mātātoko. Ko te mātauranga i te whana i waenganui i te hāngai, te wāhi, me te rēsita he mea matua mō tēnei tangata e mahi ana i ngā kōwhiringa hāngai mātātoko wāhi i tēnei āhua.

Ko te hāhā o te whiriwhiri i te rēsita tika he whakamātau i te pānga o te hōhi i te wāhi, ā, he whakamātau hoki i te rere o te wāhi e hiahia ana. Ko ngā kōwhiringa mātātoko o ngā rākau hāngai e whakamahi ana i ngā rere āhua o te wāhi, ā, inā he rere kē mai i ēnei rere ka pakaru tonu. Ko ngā whakamārama o te whakamāhuatanga o ngā LED o tēnei wā me ngā whakamārama o te whakamāhuatanga, e hiahiatia ana ngā whakamātau tātai tino pūmau kia whakamāhuatia ai te mātao, ā, kia mau tonu hoki ngā āhua haumaru o te whakamāhi. Ko tēnei tuhinga e whakamārama ana i te hāhā katoa o te whakamātau i ngā rēsita tino pūmau, e whakamārama ana i ngā uara matua me ngā whakamāhi i ngā āhua rerekē o ngā rākau.
Ko te whāinga matua o te whakamātautau i ngā hikoheke he whakamāhi i te Ture a Ohm: ko V te ōrite o I × R. I ngā take mātua, me tātari i ngā whāinga e toru i mua i te whakamāhi: te hiko o te whakauru, te pākoki o te hiko ki mua o tōu rākau hiko, me te hiko e pīrangi ana koe kia rere. Ko te pākoki o te hiko ki mua he rerekē i runga i te momo rākau e whakamāhi ana koe, i tōna pūtake hiko. Ko ngā LED whero he pākoki o te hiko ki mua i te āhua o te 2 voli, i te wā i ngā rākau hiko mā, māwhero, e hiahiatia ana te 3 ki te 4 voli, pea anō hoki.
Kei ia pūrere whakamarama hauraro he pepa raraunga e tohu ana i tōna ngaohiko anga whakamua i te nāianei tauwhāiti. He mea nui tēnei whakaritenga nā te mea e whakatau ana i te ngaohiko e wātea ana mō te resistor-rohe o te nāianei. Ina tangohia e koe te ngaohiko anga whakamua i tō ngaohiko tuku, me tuku te toenga ki te aukati. Ko ngā tono photodiode me ngā ine tōtika me ngā mahi LED e whakawhirinaki ana ki te pupuri i te pūrere i roto i tōna matapihi whakahaere. Ko te nui ake i te manawanui ngaohiko o mua ka whakaiti i te kounga o te taputapu, ka whakaiti i tona oranga mahi.
Ko ngā āhua o te rere o te wāhi mātua mō ngā LED tāwhai he 10 ki te 20 miliamp, ahakoa āhua ēnei o ngā kōhao whakamātautau pūngāwari teitei e hiahiatia ana ngā uara rerekē. Ko ngā LED pūngāwari teitei i whakamahinga ai mō ngā whakamātautau arotake i te ao hāpaiti, he 350 miliamp, pea, te rere o te wāhi mātua, ā, he whakamātautau pūmau hoki i ngā whakamātautau mō te whakamātautau i te hōhi me ngā whakamātautau mō te rere o te hōhi o ngā rēsita. Ka pai ake ngā hua o te LED i te whakamātautau i te rere o te wāhi mātua i whakamahinga ai. I te iti ake o te rere, ka iti ake te pūngāwari, ā, ka pakaru ngā hua o te wāhi; i te nui ake o te rere, ka nui ake te hōhi, ā, ka poto ake te wā o te ora.
I tē wā e whai ana koe i te hāngā o te hiko, me te rere āhua e pīrangi ana, ka māmā te whakamātau i te uara o te rēsita i te whakamātau a Ōhama. Tangohia te hiko whakamātua mai i te hiko o te hāngā kia kitea ai te hiko e ngaro ana i te rēsita. Ka whakawehea tēnei hiko e ngaro ana ki te rere āhua e pīrangi ana (i ngā ampera) kia kitea ai te uara o te rēsita i ngā ōma. He tauira, i tēnei hāngā o te hiko e 5 vōliti, he LED e 2 vōliti te hiko whakamātua, me te rere āhua e 15 miliampera, ko tōu whakamātau he (5 minus 2) whakawehea ki te 0.015, ā, he 200 ōma. Me whiriwhiri anō i te uara o te rēsita e wātea ana i ngā kaiwhakamahi, ā, me whiriwhiri i te uara e tata atu ana kia māmā ai te hoko, me te whakamana i te whai hua pai.
Ko ngā rēsita e whakamāngō i te pūhanga i runga i te whārite P = I² × R, i tēnā wā P = V × I. Ko tēnei whakamāngō pūhanga e whakawhitinga ana i te hōhi e tika ana kia whakamārama. Ko tēnei rēsita 200-ohm me ngā māriu 15 e rere mai ana i roto i a ia e whakamāngō ana i ngā wati 0.045, ā, he rēsita 0.125-watt te iti i te whāinga hei whakamārama. Mē kore e wareware ngā whakamārama pūhanga kia kore ai ngā rēsita e mātua, ā, kia kore ai ngā hāhā o te rorohiko. Ko ngā whakamātau i ngā photodiode he iti ngā rere, ā, he iti hoki ngā whakamāngō pūhanga, engari ko ngā whakamātau mō ngā LED mātua he nui ngā rere, ā, he tatau tonu ngā whakamārama mō ngā whāinga o te hōhi. Me whiriwhiri ngā rēsita e rua ngā whakamārama pūhanga kia tūpato ai mō te tāwhai i te wā roa.
Ngā uara o ngā rēsita e huringa tonu i te wāhi o te hōhā, he āhua o te whakamārama o te tātai hōhā. Ko ngā rēsita kāpura kōrero i te waenganui o ngā wāhi 100 ki ngā wāhi 500 i te miriona i te rerekētanga o te hōhā i te rerekētanga o te wāhi o te hōhā. Ahakoa ko tēnei rerekētanga i te nuinga o ngā rākau hāngā LED he whakaaetia, ko ngā whakamātautau pūnaha o ngā rākau hāngā photodiode me ngā pūnaha e hiahiatia ana te tāwhai o te hāngā o ngā LED me ōna mahinga e whai ana i ngā rēsita e iti ake ana i te tātai hōhā. Ko ngā rākau hāngā i ngā wāhi hōhā teitei, i ngā wāhi hōhā e whānui ana, e hiahiatia ana ngā rēsita kāpura mātā, e pai ake ana ngā whakamātautau. Me whakamātau tonu koe kia tika ngā mahinga o tō rēsita i ngā wāhi hōhā katoa o tō pūnaha.
He rerekē ngā whakaritenga rahi o te resistor i runga anō i te mea kei te hoahoa koe i tētahi ara iahiko raupapa, kei te whakatinana rānei i ngā topologies matatini ake. Ko ngā ara iahiko raupapa te whirihoranga māmā rawa, e whāiti ana te auau o tētahi resistor kotahi mō tētahi pūrere whakarewa marama haurua maha rānei. Ko ia whirihoranga e whakaatu ana i ngā wero rahi rerekē, me te hiahia kia aro nui ki te tohatoha ngaohiko me te toenga o te nāianei. Ko te māramatanga o ēnei rerekētanga e whakarite ana i te tōtika me te mahi pai rawa atu o te LED puta noa i ngā tono ahumahi me ngā tono kiritaki.
Ko te whāinga o te whakamātautau i te rāhui o ngā hāngā tāwhai he whakamātautau i tēnei āhua: he LED takitahi e hono ana i te tāwhai o te rāhui kia tāwhai ai i te wāhi o te hiko. Ko tēnei āhua he māmā, ā, kei ngā whakamātautau maha ngā whakamātautau mai i ngā tāwhai tohu ki ngā whakamātautau māmā o ngā whakamārama. Ka whakamātua te rākau hiko kia kore ai te wāhi o te hiko e pānui ai i te rākau hiko. I muri i tōu whakamātautau i te uara o te rāhui i runga i te ara i whakamāramatia i mua, ka māmā te whakamāhi, ā, ka tūpato. He pai tēnei ara mō ngā whakamātautau iti te hiko, engari he rerekē ngā whakamātautau o ngā LED nui te hiko, ā, he rerekē ngā hāngā o te hiko.
Ko ngā whirihoranga ōrite o ngā pūrere whakamarama haurua-kaituku e hiahiatia ana he tātari āta atu nā te mea ka wehewehea te nāianei i waenganui i ngā pūrere i runga anō i ō rātou āhuatanga ngaohiko whakamua. Ko ngā rerekētanga iti i roto i ngā pūrere whakamarama semiconductor ka puta he rerekētanga o te nāianei, kei reira ētahi pūrere e nui ake te rere o ētahi atu. Ka whakaitihia e tēnei tohatoha ōrite te kaha me te mahi o te LED katoa nā te mea he nui ake te kaha o ngā pūrere mārama, he tere ake hoki te koroheketanga. Ko ngā raupapa-rōpū ōrite e whakataurite ana i ēnei āwangawanga engari e hiahiatia ana he tāpiritanga o te aukati me ngā tātaritanga matatini ake. Ko ngā tono photodiode he maha ngā momo ara porowhita rerekē e tika ana mō te whakarei me te ine tohu, kaua ko te whakamarama noa.
Te whakamāhi i tēnei hāngā kore e iti ake nei he whakamāhi i te wāhi maha o te awa o te hau, ā, he rere kē te ngākau pōuri o tōu rākau whakamāhinga āhua, ā, he rere kē te ngākau pōuri o tēnei rākau. Ko te rākau e tāwhai ana i te hōhi, ā, e tāwhai ana i te hōhi i te wā iti tonu i te wāhi o te hau. I tēnei wā, ko te hāngā kore anō hoki e tāwhai ana i te hōhi mai i te whakamāhinga o te hau. Ko tēnei āhua he whakamārama i te take o te hāngā kore e tātai ai i te tātai tika hei whakamāhi i ngā diode me ngā LED. Me whakamātautau i ō tātai, ā, me whakamāhi i te uara o te hāngā kore e tata ana ki tō tātai, engari kāore i te iti ake.
Ko ngā tono photodiode e pā ana ki te mahi whakaheke-taupatupatu me te aro ki te marama, kaua ki te tuku marama. He rerekē ngā mahi o ngā resistor e herea ana e te nāianei i roto i ngā ara hiko photodiode, he maha ngā wā e mahi ana me ngā kaiwhakawhanake transimpedance, kaua ki ngā whirihoranga raupapa māmā. Ko te huarahi rahi e whakaaro ana ki nga whakaritenga whakarei tohu me nga ahuatanga haruru hei utu mo te putanga marama. Mā te mōhio ki tēnei rerekētanga e āwhina ai ngā kaipūkaha ki te whiriwhiri i ngā wāhanga e tika ana mō ia tono motuhake. Ahakoa e rua ngā pūrere whakarewa marama semiconductor i roto i te parau tumu, rerekē tino o ratou tūranga ara iahiko me te tikanga rahi.
Ko te whakamāhua me ngā mahi a te LED e whai ana i te rere o te wāhanga o te hiko i tātai ai i te pukapuka kōrero mō te rākau. Mēnā he iti ake ngā rēsita, ka whakamātautia te rākau i te hiko mātua; mēnā he nui ake ngā rēsita, ka heke te hiko i raro i te rere, ka pāpāhi te whakamāhua, ā, ka pakaru te hiranga o te whakamāhua. Ko te tātai i ngā rēsita e pai ana hei whakamāmā i te rākau ki tana wāhi whakamāmā, i reira ka whakamāhua te whakamāhua i tēnei wāhi, ā, ka whakamāmā hoki te roa o tana ora. Ko tēnei whanaungatanga i waenganui i te uara o te rēsita me ngā mahi o te rākau whakamāhua hiko he mea matua hei tātai i ngā whakamāmā i ngā whakamāmā i ngā rākau, i ngā whakamāmā hoki i ngā rākau.