Zener diode - nws yog dab tsi thiab nws yog dab tsi?

2024 Tus sau: Howard Calhoun | [email protected]. Kawg hloov kho: 2024-01-02 13:55

Zener diode yog ib qho semiconductor diode nrog cov khoom tshwj xeeb. Yog hais tias ib tug zoo tib yam semiconductor yog ib tug insulator thaum switched rov qab, ces nws ua hauj lwm no kom txog rau thaum ib tug tej yam nce nyob rau hauv cov ntaub ntawv voltage, tom qab uas ib tug avalanche-zoo li reversible breakdown tshwm sim. Nrog rau kev nce ntxiv hauv qhov rov qab tam sim no ntws los ntawm zener diode, qhov hluav taws xob txuas ntxiv mus tas li vim muaj qhov sib npaug ntawm qhov tsis kam. Ua li no, nws muaj peev xwm ua tiav hom kev ruaj ntseg.

Nyob rau hauv lub xeev kaw, ib qho me me tam sim no ua ntej dhau los ntawm zener diode. Lub caij coj zoo li tus resistor, tus nqi kuj yog loj. Thaum lub sij hawm tawg, qhov tsis kam ntawm zener diode ua tsis zoo. Yog hais tias peb txuas ntxiv mus nce qhov voltage ntawm lub tswv yim, lub caij pib cua sov thiab thaum lub tam sim no tshaj tus nqi tso cai, ib tug irreversible.thermal tawg. Yog tias qhov teeb meem tsis tau coj mus rau nws, thaum qhov hluav taws xob hloov pauv ntawm xoom mus rau sab saud ntawm thaj chaw ua haujlwm, cov khoom ntawm zener diode tau khaws cia.

Thaum lub zener diode tau qhib ncaj qha, cov yam ntxwv zoo ib yam li lub diode. Thaum lub plus txuas nrog rau p-thaj chaw, thiab qhov minus txuas nrog n-thaj tsam, qhov kev hloov pauv tsis zoo yog me me thiab tam sim no ntws los ntawm nws. Nws nce raws li qhov input voltage nce.

Ib lub zener diode yog ib qho tshwj xeeb diode txuas feem ntau nyob rau hauv qhov sib txawv. Lub ntsiab yog thawj zaug hauv lub xeev kaw. Nyob rau hauv qhov xwm txheej ntawm hluav taws xob tawg, qhov voltage zener diode tswj nws tas li nyob rau hauv ntau qhov tam sim no.

Ib tus rho tawm yog siv rau lub anode, thiab ntxiv rau cathode. Tshaj li stabilization (hauv qab taw tes 2), overheating tshwm sim thiab qhov tshwm sim ntawm lub caij tsis ua hauj lwm nce.

Ntse

Zener tsis muaj raws li hauv qab no:

• U_st - stabilization voltage ntawm ntsuas tam sim no I_st;
• I_{st min - yam tsawg kawg hluav taws xob tawg pib tam sim no;}
• I_{st max - siab tshaj tam sim no;}
• TKN - kub coefficient.

Tsis zoo li cov pa diode, lub zener diode yog cov khoom siv semiconductor uas cov cheeb tsam hluav taws xob thiab thermal tawg nyob deb heev ntawm qhov tam sim no-voltage yam ntxwv.

Txuas nrog qhov siab tshaj plaws tso cai tam sim no yog qhov ntsuas feem ntau teev hauvrooj - lub zog dissipation:

P_max=I_{st max}∙ U_st.

Qhov ntsuas kub ntawm qhov zener diode tuaj yeem yog qhov zoo lossis tsis zoo. Los ntawm kev sib txuas cov ntsiab lus hauv koob nrog cov coefficients ntawm cov cim sib txawv, qhov tseeb zener diodes yog tsim uas tsis nyob ntawm cov cua sov lossis cua txias.

Inclusion schemes

Cov kab hluav taws xob ntawm qhov yooj yim stabilizer, muaj cov ballast tsis kam R_{b thiab zener diode uas shunts lub load.}

Qee zaum, muaj kev ua txhaum ntawm kev ruaj khov.

1. Kev xa mus rau lub stabilizer ntawm qhov hluav taws xob loj los ntawm lub zog hluav taws xob nyob rau hauv lub xub ntiag ntawm lub lim dej capacitor ntawm cov zis. Tam sim no surges thaum them nws tuaj yeem ua rau tsis ua haujlwm ntawm zener diode lossis kev puas tsuaj ntawm cov resistor R_b.
2. Load shutdown. Thaum qhov hluav taws xob siab tshaj plaws yog siv rau cov tswv yim, qhov tam sim no ntawm zener diode yuav dhau qhov kev tso cai, uas yuav ua rau nws cov cua sov thiab kev puas tsuaj. Ntawm no nws yog ib qho tseem ceeb los saib xyuas thaj chaw ua haujlwm nyab xeeb.
3. Resistance R_{b yog xaiv me me kom qhov tsawg kawg nkaus qhov muaj peev xwm muab tau qhov hluav taws xob thiab qhov siab tshaj plaws tso cai tam sim no ntawm lub load, zener diode nyob rau hauv qhov chaw ua haujlwm.}

Thyristor tiv thaiv circuits lossis fuses yog siv los tiv thaiv lub stabilizer.

Resistor R_{b yog xam los ntawm tus qauv:}

R_b=(U_pit - U_nom)(Ist _{+ I}n_).

Tam sim nozener diode I_st yog xaiv ntawm qhov tso cai siab tshaj plaws thiab qhov tsawg kawg nkaus, nyob ntawm qhov input voltage U_pit thiab thauj khoom tam sim no I _n.

Zener Xaiv

Cov ntsiab lus muaj qhov sib kis loj hauv qhov hluav taws xob ruaj khov. Kom tau txais tus nqi tseeb ntawm U_{n, zener diodes raug xaiv los ntawm tib pawg. Muaj ntau hom uas muaj qhov nqaim ntawm qhov tsis muaj. Nrog lub zog siab dissipation, cov ntsiab lus tau nruab rau ntawm lub tshuab hluav taws xob.}

Txhawm rau xam qhov tsis muaj ntawm zener diode, thawj cov ntaub ntawv yuav tsum tau ua, piv txwv li, cov no:

• U_{pit=12-15 V - input voltage;}
• U_{st=9 V - stabilized voltage;}
• R_{n=50-100 mA - load.}

Cov tsis muaj yog ib yam rau cov khoom siv uas siv hluav taws xob tsawg.

Rau qhov tsawg kawg nkaus input voltage ntawm 12 V, tam sim no ntawm lub load raug xaiv rau qhov siab tshaj plaws - 100 mA. Raws li Ohm txoj cai, koj tuaj yeem pom tag nrho cov khoom ntawm lub voj voog:

R_{∑=12 V / 0.1 A=120 Ohm.}

Ntawm lub zener diode, qhov hluav taws xob poob yog 9 V. Rau qhov tam sim no ntawm 0.1 A, qhov sib npaug yuav yog:

R_{eq=9 V / 0.1 A=90 Ohm.}

Tam sim no koj tuaj yeem txiav txim siab qhov tsis kam ntawm ballast:

R_{b=120 Ohm - 90 Ohm=30 Ohm.}

Nws raug xaiv los ntawm tus qauv kab, qhov twg tus nqi yog tib yam li tus lej suav.

Qhov siab tshaj plaws tam sim no los ntawm zener diode yog txiav txim siab los ntawm kev txiav txim siab ntawm kev thauj khoom kom nws tsis ua haujlwm yog tias cov xaim tsis raug. Qhov hluav taws xob poob hla qhov resistor yuav yog:

U_{R=15 - 9=6 B.}

Tom qab ntawd qhov tam sim no dhau los ntawm tus resistor yog txiav txim siab:

I_{R=6/30=0, 2 A.}

Vim lub zener diode txuas nrog nws, I_c=I_{R=0.2 A.}

Power dissipation yuav P=0.2∙9=1.8 W.

Raws li qhov tsis tau txais, xaiv qhov tsim nyog Zener diode D815V.

Symmetrical zener diode

Symmetrical diode thyristor yog ib qho khoom siv hloov pauv uas ua haujlwm hloov tam sim no. Ib tug feature ntawm nws cov hauj lwm yog ib tug voltage poob mus txog rau ob peb volts thaum tig nyob rau hauv lub ntau yam ntawm 30-50 V. Nws yuav tsum tau hloov los ntawm ob counter-connected pa zener diodes. Cov cuab yeej siv los ua cov khoom hloov pauv.

Analogue ntawm zener diode

Thaum tsis tuaj yeem nrhiav cov khoom tsim nyog, lawv siv ib qho analogue ntawm zener diode ntawm transistors. Lawv qhov zoo dua yog qhov muaj peev xwm ntawm kev tswj hluav taws xob. Multi-theem DC amplifiers tuaj yeem siv rau qhov no.

Ib qho hluav taws xob faib hluav taws xob nrog lub ntsuas hluav taws xob R1 tau teeb tsa ntawm lub tswv yim. Yog hais tias lub input voltage nce, nyob rau hauv lub hauv paus ntawm transistor VT1 nws kuj nce. Nyob rau tib lub sijhawm, tam sim no los ntawm transistor VT2 nce, uas them rau qhov nce ntawm qhov voltage, yog li tswj nws ruaj khov ntawm cov zis.

Kev kos npe ntawm zener diodes

iav zener diodes thiab zener diodes hauv cov yas yog tsim. Hauv thawj kis, 2 tus lej raug siv rau lawv, ntawm qhov uas tsab ntawv V nyob. U_{st=9, 1 V.}

Nyob rau hauv cov ntaub ntawv yas, cov ntawv sau yog deciphered siv cov ntaub ntawv, qhov twg koj tuaj yeem pom lwm yam tsis muaj.

Lub nplhaib tsaus nti ntawm rooj plaub qhia lub cathode uas txuas ntxiv txuas ntxiv.

Zaj lus

A zener diode yog diode nrog cov khoom tshwj xeeb. Qhov kom zoo dua ntawm zener diodes yog ib theem siab ntawm voltage stabilization nrog ntau yam kev hloov pauv tam sim no, nrog rau kev sib txuas yooj yim. Txhawm rau kom ruaj khov qhov hluav taws xob me me, cov khoom siv tau hloov mus rau pem hauv ntej, thiab lawv pib ua haujlwm zoo li cov diodes zoo tib yam.