Isifundo Sokuhlanganisa Umsakazo we-AM Ngesistimu Yokuphakelwa Kwamandla
Umsakazo we-AM (Amplitude Modulation) ungomunye wemisakazo yokwamukela umculo esezingeni eliphezulu futhi elula ukuyifunda. Nakuba abantu abaningi manje sebeshintshela kumsakazo wedijithali noma wokusakaza, ukwakha umsakazo we-AM kusalokhu kuyiphrojekthi ye-elekthronikhi ethokozisayo, kufundisa izisekelo zesekethe ze-radio frequency (RF), ukushuna, ukutholwa kwesignali, kanye nokukhulisa umsindo. Kulesi sifundo, sizoxoxa ngendlela yokwakha umsakazo we-AM olula ophelele ngohlelo lokunikezwa kwamandla oluzinzile, okuvumela umsakazo ukuthi usebenze ngokuqhubekayo kunokuthembela kumabhethri kuphela.
> Qaphela: Lesi sihloko senzelwe ukuhlanganisa umsakazo we-AM olula kusetshenziswa izingxenye ezitholakala kalula. Uma ungumqali, sicela uqaphele futhi uqedele ukuhlanganisa kwakho, njengoba i-polarity engalungile noma ukubekwa kwezingxenye kungabangela ukungasebenzi kahle kwesekethe.
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1. Isimiso Esifushane Sokusebenza Somsakazo we-AM
Umsakazo we-AM usebenza ngokuthwebula amaza omsakazo we-AM nge-antenna, bese ukhetha amaza athile usebenzisa isekethe ye-LC tuner (i-inductor L kanye ne-variable capacitor C). Isignali ekhethiwe bese ingena kumtholi ukuze ihlukanise ulwazi lomsindo kumphathi. Isignali yomsindo ibe isikhuliswa yi-amplifier yomsindo bese ekugcineni ikhishwa ngezipikha noma ama-earphone.
Ngokuvamile, ibhulokhi yomsakazo elula ye-AM iqukethe:
1. I-Antena kanye nomhlabathi
2. Ishuna ye-LC (isikhethi semvamisa)
3. I-detector (i-diode/i-rectifier yesignali)
4. Izihlungi zomsindo
5. Isikhulisi somsindo
6. Ukunikezwa kwamandla
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2. Uhlu Lwezingxenye Ezidingekayo
Izingxenye ezilandelayo zivame ukusetshenziswa kumsakazo we-AM olula one-amplifier yomsindo kanye nokunikezwa kwamandla:
A. Isigaba se-RF kanye ne-Detector
– 1 × Induku yeFerrite + ikhoyili ye-AM (ingathathwa kumsakazo osetshenzisiwe)
– 1 × i-variable capacitor (i-polyvaricon ye-gang 2 ingcono, kodwa i-gang 1 yanele)
– 1 × Germanium diode (isib. 1N60 noma OA90) ye-detector
(Uma kunzima, ungasebenzisa i-Schottky diode efana ne-BAT43, yize izici zingase zihluke)
– 1 × 10 nF–100 nF capacitor (isihlungi somsindo esivela kumtshina)
– 1 × 100 kΩ–1 MΩ resistor (umthwalo we-detector, uma uthanda kuye ngomklamo)
B. Isikhulisi Somsindo
Inketho ewusizo kakhulu:
– 1 × IC LM386 (kulula ukuyihlanganisa i-amplifier yomsindo enamandla aphansi)
– 1 × I-Potentiometer 10 kΩ (ivolumu)
– 1 × 100 µF–470 µF i-capacitor (ukuxhumanisa okukhiphayo nesipikha)
– 1 × 10 µF capacitor (i-LM386 gain, uma uthanda)
– 1 × 100 nF capacitor (ukuhlukanisa ukunikezwa eduze kwe-IC)
– 1× 8 Ω Isipikha (0,5–1 W)
C. Uhlelo Lokuphakelwa Kwamandla
Izinketho eziphephile nezivamile:
– I-adaptha ye-9–12 V DC (ubuncane obungu-300 mA)
– 1 × Diode 1N4007 (ukuvikelwa kwe-polarity engemuva)
– 1 × Umlawuli 7809 (umphumela ozinzile we-9 V) noma 7805 (5 V uma isekethe yakho ingu-5 V)
– I-capacitor yokufaka engu-1 × 470 µF
– 1 × 220 µF i-capacitor yokukhipha
– Ama-capacitor angu-2 × 100 nF (eduze kwemilenze yokulawula, okokufaka kanye nokokukhipha)
– Iswishi yokuvula/yokuvala
– I-LED + 1 kΩ resistor (inkomba yamandla, uma uthanda)
> Kungani kudingeka isilawuli? Ngoba imisakazo (ikakhulukazi ingxenye ye-RF) izinzile kakhulu uma i-voltage ingaguquguquki. I-hum kanye nokuphambuka kungancishiswa uma ugesi uhlanzekile.
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3. Umklamo Webhulokhi Yesekethe
Ukuze kube lula, klama umsakazo wakho we-AM kanje:
1. I-Tuner: ikhoyili ye-ferrite + i-capacitor eguquguqukayo yakha i-resonance ukuze ikhethe iziteshi.
2. I-Detector: i-germanium diode ilungisa isignali ye-RF ibe isignali yomsindo.
3. Ivolumu: i-potentiometer ilawula ukuthi umsindo ongakanani ongena ku-amplifier.
4. I-amplifier ye-LM386: yandisa umsindo ngokwanele ukushayela isikhulumi.
5. Ukunikezwa kwamandla kagesi angu-9 V: i-adaptha → ukuvikelwa kwe-diode → isilawuli esingu-7809 → isihlungi.
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4. Isigaba Sokuhlanganisa Isinyathelo Ngesinyathelo
Isinyathelo 1 — Lungisa Ukunikezwa Kwamandla Okuzinzile
Qala kusukela ekuhlinzekweni kwamandla ngoba lokhu kunquma ukuzinza kwesekethe yonke.
1. Xhuma i-adaptha engu-9–12 V DC kwisekethe yokuvikela i-polarity:
– I-adaptha Enhle → I-1N4007 diode → iya kokufakwayo okungu-7809
– I-adaptha engalungile → indawo yesekhethi
2. Faka i-capacitor:
– 470 µF ehambisana nokufakwa komlawuli phansi
– 100 nF eduze komlenze wokufaka womlawuli phansi
– 220 µF okuhambisana nokukhipha komlawuli phansi
– 100 nF eduze komlenze wokukhipha womlawuli phansi
3. Faka inkinobho ethi ON/OFF emugqeni omuhle ngaphambi kokungena kumlawuli (noma ngemva komlawuli).
4. Uma usebenzisa i-LED ekhombisa ukukhanya, xhuma i-LED + 1 kΩ resistor kusukela ku-9 V output uye phansi.
Hlola nge-multimeter: umphumela kufanele ube cishe yi-9 V DC eqinile.
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Isinyathelo 2 — Hlanganisa i-LM386 Audio Amplifier
Isekethe ye-LM386 yaziwa ukuthi ilula futhi ifanelekela umsakazo we-AM.
1. Amaphini abalulekile e-LM386:
– Iphinikhodi 6: I-VCC (9 V)
– Iphini 4: I-GND
– Iphinikhodi 3: okokufaka umsindo
– Iphini 5: okukhiphayo kusipika nge-electrolytic capacitor
2. Faka i-capacitor engu-100 nF kusuka ku-VCC kuya ku-GND eduze kwe-IC ukuze unciphise umsindo.
3. Faka i-potentiometer engu-10 kΩ njengokulawula ivolumu:
– Ukuphela kwebhodwe → isignali yomsindo evela kumtshina
– Okunye ukuphela → umhlabathi
– Umlenze ophakathi (i-wiper) → okokufaka kwe-LM386 (iphinikhodi 3)
4. Umphumela wesipikha:
– Iphinikhodi 5 LM386 → i-capacitor yochungechunge 220–470 µF → isikhulumi 8 Ω → phansi
Uma ufuna inzuzo ephezulu, faka i-capacitor engu-10 µF phakathi kwephini 1 nephini 8 ye-LM386 (ongakukhetha).
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Isinyathelo 3 — Hlanganisa i-LC Tuner (Ingxenye Yokubamba Isiteshi)
Le ngxenye “ezwela kakhulu” futhi inquma ikhono lokwamukela ukusakazwa.
1. Sebenzisa induku ye-ferrite ene-AM coil:
– Ngokuvamile kuba nama-coil amabili: elilodwa lokulungisa, elinye lokuhlanganisa.
2. Xhuma ikhoyili yokulungisa ngokuhambisana ne-capacitor eguquguqukayo.
Lokhu kwakha isekethe ephendulayo ukuze kukhethwe imvamisa.
3. Nge-antenna, ungenza okulandelayo:
– Thembela ku-ferrite rod njenge-antenna yangaphakathi (eyanele izindawo zesignali eziqinile), noma
– Engeza amamitha ambalwa ekhebula le-antenna endaweni yokuxhuma (qaphela ukuthi ungenzi isekethe ibe “nzima” kakhulu ukuze ukulungiswa kwelulwe).
Icebiso: Gcina ingxenye yeshuna kude nekhebula lokuhambisa ugesi kanye nezintambo zesipikha ukuze ugweme ukubamba umsindo.
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Isinyathelo 4 — Faka i-AM Detector
Ama-detector alula asebenzisa ama-germanium diode ngoba i-voltage yawo yaphambili iphansi, afanelekela izimpawu ze-AM ezibuthakathaka.
1. Umphumela ovela kusekethe yeshuna uya ku-diode engu-1N60.
2. Ngemva kwe-diode, namathisela i-capacitor engu-10 nF–100 nF phansi ukuze ususe ingxenye ye-RF ushiye umsindo kuphela.
3. Thatha isignali yomsindo kusukela endaweni engemuva kwe-diode kanye ne-filter capacitor, bese uyidlulisela ku-volume potentiometer.
Uma umsindo uphansi kakhulu noma unomsindo omkhulu, ungazama ukushintsha inani le-filter capacitor (isb. 10 nF ukuze ugcine i-treble ingcono, 100 nF ukuze kube nomsindo obushelelezi).
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5. Izintambo Zomhlabathi Nokuhlelwa Kwazo
Emsakazweni, ukwakheka kuvame ukuba kubaluleke kakhulu kunethiyori yesekethe. Eminye imithetho ebalulekile:
– Dala umhlabathi onenkanyezi: xhuma umhlabathi endaweni ephakathi eduze kwe-capacitor yokukhipha yomlawuli.
– Hlukanisa imigqa yomhlaba yomsindo neye-RF ngangokunokwenzeka bese uyihlanganisa ngesikhathi esisodwa.
– Ikhebula elisuka ku-tuner liye ku-detector kumele libe lifushane.
– Gcina ikhoyili ye-ferrite kude ne-adaptha transformer (uma i-adaptha iwuhlobo lwe-transformer) noma kumamojula okushintsha anomsindo.
Uma usebenzisa i-adaptha yokushintsha eshibhile futhi uzwa umsindo/umdumo, zama:
– Engeza i-capacitor engu-1000 µF ekufakweni,
– Faka i-inductor encane (i-choke) ngokulandelana emgqeni wokuhambisa,
– Noma sebenzisa i-adaptha yekhwalithi engcono.
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6. Ukuhlola Nokulungisa
Uma konke sekufakiwe:
1. Vula ugesi, qiniseka ukuthi i-LM386 ayishisi ngokweqile.
2. Jikelezisa i-capacitor eguquguqukayo kancane ukuze useshe isiteshi.
3. Lungisa ivolumu ku-potentiometer.
4. Uma ungabambi lutho:
– Hlola uxhumano lwekhoyili ne-capacitor eguquguqukayo (ihambisana kahle)
– Qiniseka ukuthi i-detector diode ayiguquki.
- Qiniseka ukuthi inhlabathi ixhunywe kahle
– Zama ukusebenzisa i-antenna yekhebula ende noma ukuhambisa indawo eduze kwefasitela.
Ukuze wandise ukuzwela, ungangeza isigaba se-transistor RF (preamp) ngaphambi kwe-detector, kodwa lokho kungaphezu kwamandla emisakazo eminingi elula.
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7. Isiphetho
Ukwakha umsakazo we-AM ngesistimu yokuphakelwa kwamandla kuyiphrojekthi enhle kakhulu yokuqonda ama-elekthronikhi asebenzayo: kusukela ekulungisweni kwe-LC kanye nokutholwa kwesignali kuya ekukhulisweni komsindo. Ukunikezwa kwamandla okulawulwayo (njenge-7809) kuzohlinzeka ngokuqina okwengeziwe, kunciphise umsindo, futhi kuthuthukise ukusebenza uma kuqhathaniswa nomthombo we-voltage oshintshashintshayo. Uma usunalo msakazo oyisisekelo, unganwebeka kwamanye amaphrojekthi, njengokwengeza i-RF amplifier, izihlungi ezingcono, noma ngisho nokuzama isekethe ye-superheterodyne.
Uma ufuna, ngingakusiza futhi ukuthi udale i-circuit schematic ephelele (umdwebo) ngokusekelwe ezingxenyeni onazo, noma wenze ngezifiso ugesi (isb. sebenzisa amabhethri ashajwayo angu-18650 + ishaja + ukwehla) ukuze uwenze uphatheke kalula.
