Mehlala ea Lipotso Tse Buisanang ka Li-diode tse Ntšang Leseli (Li-LED)
Diode e ntšang leseli (LED) ke sesebelisoa sa semiconductor se ntšang leseli ha motlakase o phalla ka har'a sona. Ketsahalo e ka morao ho li-LED e tsejoa e le electroluminescence, moo thepa ea semiconductor e ntšang leseli ha e tsosoa ke motlakase. Li-LED li se li tumme haholo lits'ebetsong tse fapaneng ka lebaka la bokhoni ba tsona bo phahameng le bophelo bo bolelele ha li bapisoa le mehloli ea leseli ea setso joalo ka li-bulb tsa incandescent.
Sehloohong sena, re tla tšohla mehlala e meng ea mathata a amanang le li-LED le ho hlalosa litharollo le lipuisano tsa tsona ka botlalo ho thusa ho utloisisa mohopolo o ka morao ho ketsahalo ena.
Mohlala oa Potso ea 1: Litšobotsi tsa Motheo tsa Mabone a LED
Potso: LED e na le bokgoni ba ho ntsha lesedi ka bolelele ba leqhubu ba 650 nm (nanometers). Bala matla a difotene tse ntshwang ke LED ena ka di-electron-volts (eV).
Puisano:
Matla a photon a ka baloa ho sebelisoa equation ea Planck:
\[ E = \frac{hc}{\lambda} \]
Moo:
– \( E \) ke matla a photon,
– \( h \) ke phetolelo ya Planck e sa fetoheng (\(6.626 \times 10^{-34} \text{ Js}\)),
– \( c \) ke lebelo la khanya (\(3 \makgetlo a 10^8 \text{ m/s}\)),
– \( \lambda \) ke bolelele ba leqhubu la lesedi (650 nm kapa \(650 \makgetlo a 10^{-9} \text{ m}\)).
Ho kenya boleng bona sebakeng sa equation ho fana ka litholoana tse latelang:
\[
E = \frac{6.626 \times 10^{-34} \times 3 \times 10^8}{650 \times 10^{-9}}
= \frac{1.9878 \times 10^{-25}}{650 \times 10^{-9}}
= 3.05 \makgetlo a 10^{-19} \mongolo{J}
\]
Ka mor'a moo, re fetolela Joules ho li-electron-volts re sebelisa phetoho \(1 \text{ eV} = 1.602 \times 10^{-19} \text{ J}\):
\[
E = \frac{3.05 \times 10^{-19}}{1.602 \times 10^{-19}}
≈ 1.90 \mongolo{eV}
\]
Kahoo, matla a photon a hlahisoang ke LED e nang le bolelele ba leqhubu ba 650 nm ke hoo e ka bang 1.90 eV.
Mohlala oa 2: Motlakase oa LED o Fetelang Pele
Potso: LED e khubelu e na le motlakase o ka pele oa 2V 'me e hloka motlakase oa 20 mA hore e sebetse hantle. Bala matla a sebelisoang ke LED.
Puisano:
Ho bala matla a monngoang ke LED, re sebelisa equation ea motheo bakeng sa matla, e leng:
\[ P = V \makgetlo a I \]
Moo:
– \( P \) ke matla a Watts (W),
– \( V \) ke motlakase ho Volts (V),
– \( I \) ke motlakase o teng ho Amperes (A).
Kenya boleng bona sebakeng sa equation:
\[
P = 2 \mongolo{V} \makgetlo a 20 \mongolo{mA}
= 2 \mongolo{V} \makgetlo 0.02 \mongolo{A}
= 0.04 \mongolo{W}
\]
Kahoo, matla a monngoang ke LED e khubelu e sebetsang ka motlakase o ka pele oa 2V le motlakase oa 20 mA ke 0.04 Watts.
Mohlala oa 3: Bokgoni ba LED
Potso: LED e putsoa e na le bokgoni ba quantum ba 30%. Haeba LED e sebelisa 0.1 W ea matla a motlakase, ke matla a makae a hlahisoang e le leseli?
Puisano:
Bokgoni ba quantum (η) ke karolelano ya matla a lokollwang ka mokgwa wa lesedi (P_luminous) ho keno ya matla a motlakase (P_input):
\[ η = \frac{P_{\text{luminous}}}{P_{\text{input}}} \]
Ho fumana \( P_{\text{luminous}} \), sebedisa equation e latelang ka boleng ba bokgoni ba 30% kapa 0.30:
\[
0.30 = \frac{P_{\text{luminous}}}{0.1 \text{W}}
\]
Ka hona:
\[
P_{\text{luminous}} = 0.30 \makhetlo a 0.1 \text{W}
= 0.03 \mongolo{W}
\]
Kahoo, matla a ntšitsoeng ke LED ka mokhoa oa leseli ke 0.03 Watt.
Mohlala Bothata ba 4: Potoloho ea Letoto la LED
Potso: U na le li-LED tse tharo tse nang le motlakase o ka pele oa 2V ka 'ngoe tse hlokang ho hokeloa ka tatellano. Haeba mohloli oa motlakase ke 9V, fumana boleng ba resistor bo hlokahalang ho fokotsa motlakase ho 20 mA.
Puisano:
Ha di-LED di hokahantswe ka tatellano, motlakase o hlokahalang ke kakaretso ya di-voltage tse ka pele tsa LED ka nngwe:
\[
V_{kakaretso} = V_f1 + V_f2 + V_f3
= 2V + 2V + 2V
= 6V
\]
Motlakase o setseng o lokelang ho qhalwa ke resistor ke:
\[
V_{R} = V_{mohloli} – V_{kakaretso}
= 9V – 6V
= 3V
\]
Ka hona joale e lakatsehang ea 20 mA, boleng ba resistor bo baloa ho sebelisoa Molao oa Ohm:
\[
R = \frac{V_{R}}{I}
= \frac{3V}{20 \text{mA}}
= \frac{3V}{0.02A}
= 150 \Omega
\]
Kahoo, boleng bo hlokahalang ba resistor ke 150 ohms.
Mohlala oa 5: Potoloho ea Moeli oa Hona Joale oa LED e Tšoanang
Potso: Potolohong, ho na le li-LED tse peli tse bapileng, e 'ngoe le e 'ngoe e na le motlakase o ka pele oa 2V le motlakase o ka pele oa 20 mA. Ke bokae kakaretso ea motlakase e hlokahalang ho tsoa mohloling oa motlakase oa 5V haeba resistor e sebelisoa bakeng sa LED ka 'ngoe?
Puisano:
Bakeng sa li-LED tse hlophisitsoeng ka ho lekana, LED ka 'ngoe e tla ba le motlakase o tšoanang, e leng motlakase oa tsona o eang pele, 'me kaha li hloka 20 mA ea motlakase ka LED, motlakase o felletseng ke:
\[
Ke_{kakaretso} = Ke_1 + Ke_2
= 20 \mongolo{ mA} + 20 \mongolo{ mA}
= 40 \mongolo{mA}
\]
Ho bala boleng ba resistor bakeng sa LED ka 'ngoe:
\[
V_{R} = V_{mohlodi} – V_f
= 5V – 2V
= 3V
\]
Boleng ba resistor ho fokotsa hona joale ho LED ka 'ngoe ke:
\[
R = \frac{V_{R}}{I}
= \frac{3V}{20 \text{mA}}
= \frac{3V}{0.02A}
= 150 \Omega
\]
Kahoo, LED ka 'ngoe e hloka resistor ea 150 ohm. Kakaretso ea hona joale e hlokahalang ho tsoa phepelong ea motlakase ea 5V ke 40 mA.
Qetello
Li-LED ke likarolo tsa bohlokoa lisebelisoa tsa elektroniki tsa sejoale-joale ka lebaka la bokhoni ba tsona ba ho fana ka mabone a sebetsang hantle haholo ka nako e telele. Ho utloisisa likhopolo tsa motheo tse kang motlakase o eang pele, motlakase o kenang, matla, katleho ea quantum, le mokhoa oa ho li hlophisa potolohong ho tla fana ka motheo o tiileng bakeng sa lits'ebetso tse sebetsang. Mehlala e kaholimo ke mohato oa pele oa ho tseba lits'ebetso le lipalo tse fapaneng tse amanang le ts'ebeliso ea li-LED lipotolohong tsa elektroniki.
