Misalai shi ne Phototransistors?

Zanen da Phototransistors?

Takardun Phototransistor

Phototransistor shine karamin kayayyakin da ke taimakawa wani ƙasashen base mai ƙarfi don gano da ƙarin shiga na tsari.

Phototransistors suna cikin kayayyaki da suka samu uku (emitter, base, da collector) ko biyu (emitter da collector) kuma suka ƙarfin base. Idan duk transistorsuna na ƙarfin, phototransistors su ne suka zama da ƙarfin da suke daidai. Suna nufin da suka amfani da hanyoyi da za su iya kawo da yawan collector da base mafi yawa da transistors masu asali. Phototransistors suna iya samun sahihi na homojunction, wanda ake nufin da suka yi daga wata abincin kamar silicon, ko heterojunction, wanda ake nufin da suka yi daga abubuwa daban-daban.

A nan phototransistors na homojunction, wannan kayayyakin zai ƙunshi wata abinci; ya kunshi silicon ko germanium. Amma don zama da ƙarfi mafi yawa, phototransistors suna iya nufin da abubuwan Group III-V kamar GaAs a fadada pn junction, wanda yana ba su heterojunction. Duk da cewa heterojunction devices suna da ƙarfi, homojunction devices suna da mu'amala mafi yawa saboda hanyoyin marubuta.

Alamomin circuit symbol npn phototransistors ta haɗa da Figure 2 ya ƙunshi transistor da biyu arrows wanda suka nuna ƙarfin light. Don pnp phototransistors, alamomin ya fi dace, amma arrow a emitter ya baka waɗanda ba shi ba.

Prinsipin Aiki

Phototransistors sun yi aiki da ƙarfin base current da intensity of light, wanda ya ba su karfin a switch da amplification applications.

Abubuwan Configuration

Phototransistors suna iya nufin da common collector ko common emitter configurations, kamar transistors masu asali.

Faktobin Output

Output phototransistor yana ƙunshi wavelength da light ya shiga, area da ke bayyana collector-base junction, da DC current gain na transistor.

Muhimmin Phototransistor

Muhimmanci na phototransistors sun ƙunshi:

• Soyayya, mafi girma, da kuma ƙarfin mafi yawa.

• Mafi girma, mafi ƙarfin, da kuma aiki mafi yawa daga photodiodes.

• Ya ba output voltage mafi yawa daga photo resistors.

• Ƙarfin da takaitaccen wavelengths daga ultraviolet (UV) zuwa infrared (IR) har zuwa visible radiation.

• Ƙarfin da kadan mafi yawa sources including incandescent bulbs, fluorescent bulbs, neon bulbs, lasers, flames, and sunlight.

• Mafi inganci da kuma temporally stable.

• Dabba da avalanche photodiodes.

• Yana cika a matsayin manyan abubuwan package types including epoxy-coated, transfer-molded, and surface mounted.

Dalilai Phototransistor

Dalilai na phototransistors sun ƙunshi:

• Ba zan iya ƙara high voltages idan an yi da silicon.

• An yi da electric spikes and surges.

• An yi da electromagnetic energy.

• Ba zan iya ƙara easy flow of electrons kamar electron tubes.

• Poor high frequency response due to a large base-collector capacitance.

• Ba zan iya ƙara low levels of light better than photodiodes.

Applications

• Object detection

• Encoder sensing

• Automatic electric control systems such as in light detectors

• Security systems

• Punch-card readers

• Relays

• Computer logic circuitry

• Counting systems

• Smoke detectors