Ronald M Benrey Popular Books
Ronald M Benrey Biography & Facts
A unijunction transistor (UJT) is a three-lead electronic semiconductor device with only one junction. It acts exclusively as an electrically controlled switch. The UJT is not used as a linear amplifier. It is used in free-running oscillators, synchronized or triggered oscillators, and pulse generation circuits at low to moderate frequencies (hundreds of kilohertz). It is widely used in the triggering circuits for silicon controlled rectifiers. In the 1960s, the low cost per unit, combined with its unique characteristic, warranted its use in a wide variety of applications like oscillators, pulse generators, saw-tooth generators, triggering circuits, phase control, timing circuits, and voltage- or current-regulated supplies. The original unijunction transistor types are now considered obsolete, but a later multi-layer device, the programmable unijunction transistor, is still widely available. Types There are three types of unijunction transistor: The original unijunction transistor, or UJT, is a simple device that is essentially a bar of n-type semiconductor material into which p-type material has been diffused somewhere along its length, fixing the device parameter η {\displaystyle \eta } (the "intrinsic stand-off ratio"). The 2N2646 model is the most commonly used version of the UJT. The complementary unijunction transistor, or CUJT, is a bar of p-type semiconductor material into which n-type material has been diffused somewhere along its length, defining the device parameter η {\displaystyle \eta } . The 2N6114 model is one version of the CUJT. The programmable unijunction transistor, or PUT, is a multi-junction device that, with two external resistors, displays similar characteristics to the UJT. It is a close cousin to the thyristor and like the thyristor consists of four p-n layers. It has an anode and a cathode connected to the first and the last layer respectively, and a gate connected to one of the inner layers. PUTs are not directly interchangeable with conventional UJTs but perform a similar function. In a proper circuit configuration with two "programming" resistors for setting the parameter η {\displaystyle \eta } , they behave like a conventional UJT. The 2N6027, 2N6028 and BRY39 models are examples of such devices. Applications Unijunction transistor circuits were popular in hobbyist electronics circuits in the 1960s and 1970s because they allowed simple oscillators to be built using just one active device. For example, they were used for relaxation oscillators in variable-rate strobe lights. Later, as integrated circuits became more popular, oscillators such as the 555 timer IC became more commonly used. In addition to its use as the active device in relaxation oscillators, one of the most important applications of UJTs or PUTs is to trigger thyristors (silicon controlled rectifiers (SCR), TRIACs, etc.). A DC voltage can be used to control a UJT or PUT circuit such that the "on-period" increases with an increase in the DC control voltage. This application is important for large AC current control. UJTs can also be used to measure magnetic flux. The Hall effect modulates the voltage at the PN junction. This affects the frequency of UJT relaxation oscillators. This only works with UJTs. PUTs do not exhibit this phenomenon. Construction The UJT has three terminals: an emitter (E) and two bases (B1 and B2) and so is sometimes known a "double-base diode". The base is formed by a lightly doped n-type bar of silicon. Two ohmic contacts B1 and B2 are attached at its ends. The emitter is of heavily-doped p-type material. The single PN junction between the emitter and the base gives the device its name. The resistance between B1 and B2 when the emitter is open-circuit is called interbase resistance. The emitter junction is usually located closer to base-2 (B2) than base-1 (B1) so that the device is not symmetrical, because a symmetrical unit does not provide optimum electrical characteristics for most of the applications. If no potential difference exists between its emitter and either of its base leads, there is an extremely small current from B1 to B2. On the other hand, if an adequately large voltage relative to its base leads, known as the trigger voltage, is applied to its emitter, then a very large current from its emitter joins the current from B1 to B2, which creates a larger B2 output current. The schematic diagram symbol for a unijunction transistor represents the emitter lead with an arrow, showing the direction of conventional current when the emitter-base junction is conducting a current. A complementary UJT uses a p-type base and an n-type emitter, and operates the same as the n-type base device but with all voltage polarities reversed. The structure of a UJT is similar to that of an N-channel JFET, but p-type (gate) material surrounds the N-type (channel) material in a JFET, and the gate surface is larger than the emitter junction of UJT. A UJT is operated with the emitter junction forward-biased while the JFET is normally operated with the gate junction reverse-biased. The UJT is a current-controlled negative resistance device. Device operation The device has a unique characteristic in that when it is triggered, its emitter current increases regeneratively until it is restricted by the emitter power supply. It exhibits a negative resistance characteristic and so it can be employed as an oscillator. The UJT is biased with a positive voltage between the two bases. This causes a potential drop along the length of the device. When the emitter voltage is driven approximately one diode voltage above the voltage at the point where the P diffusion (emitter) is, current will begin to flow from the emitter into the base region. Because the base region is very lightly doped, the additional current (actually charges in the base region) causes conductivity modulation, which reduces the resistance of the portion of the base between the emitter junction and the B2 terminal. This reduction in resistance means that the emitter junction is more forward biased, and so even more current is injected. Overall, the effect is a negative resistance at the emitter terminal. This is what makes the UJT useful, especially in simple oscillator circuits. Invention The unijunction transistor was invented as a byproduct of research on germanium tetrode transistors at General Electric. It was patented in 1953. Commercially, silicon devices were manufactured. A common part number is 2N2646. References . Discover the Ronald M Benrey popular books. Find the top 100 most popular Ronald M Benrey books.
Best Seller Ronald M Benrey Books of 2024
-
Doubly Claimed
C.D. GorriWill this curvy redhead find her match with two smexy shifters? Needing a break from her nightmare boss, Ginger is more than ready for the Freeman sisters' annual vacation. Sh...
-
Just One Time
Samantha BacaThere are worse things than turning forty.    However, I can't seem to evade my worry of my biological clock, and my fear that time is running out. I've...
-
Destined Magic
Ruby RaineI'm twentyeight, still single, no career, just inherited a mansion filled with magical secrets, three cats, plus a demon hellbent on killing kill me because supposedly, I'...
-
Meditations
Marcus AureliusWritten in Greek by the only Roman emperor who was also a philosopher, without any intention of publication, the Meditations of Marcus Aurelius offer a remarkable series of challen...
-
Imperfect Chemistry
Mary FrameShe's never understood the point of romance, but now he's going to show her. Lucy London puts the word genius to shame. Having obtained her PhD in microbiology by the age...
-
Through the Looking-Glass
Lewis CarrollAn Apple Books Classics edition. Travel back to Wonderland in Lewis’s acclaimed sequel to Alice’s Adventures in Wonderland . When Alice’s game of “Let’s pretend” turns real, she fi...
-
Behind Closed Doors
Sherri HayesFalling For His New Neighbor Was Never Part of the Plan  Chris Daniels is single, and he prefers to keep it that way. Women are trouble. One look at his new neighbor has a...
-
10-Minute Social Psychology
Albert RutherfordWould you like to instantly catch people's thoughts, emotions, motivations, and intentions through mere observation? If yes, you've come to the...
-
Scorned Queen
Lisa Renee JonesThe protégé king wants the king unseated but it will be war, and a bloody one. And you can only push a future queen so far before she says enough, and proves she's as worthy f...
-
No Room For Regret
Janeen Ann O'ConnellThe movement of the ship seals his fate. He could be sailing anywhere, anytime, but he's not, he's going to the other side of the world. He could be anyone, but he's...
-
Collided
Portia MooreAlex I want Madison the moment I lay eyes on her. But I’ve got my work cut out for me because someone before me broke her heart and destroyed her trust. She's my friend, that&...
-
The Wedding Bet
Susan HatlerA fun and uplifting story that will make you swoon and smile as two best friends fall in love. Kennedy needs to slow down, which is why her last boyfriend broke up with her. No mat...
-
The Three Little Pigs
Mark LeskyClassic fairy tales, legends and folk stories in short version without violence retold with lovely illustrations in simple language. Perfect for reading aloud to small chi...
-
The Great Gatsby
F. Scott FitzgeraldAn Apple Books Classics edition. The Roaring Twenties are in full effect in F. Scott Fitzgerald’s riveting classic. Manabouttown Jay Gatsby seems to have it all, including loads of...
-
The Scarlet Letter
Nathaniel HawthorneAn Apple Books Classic edition. Hester Prynne lives in infamy. After committing adultery and bearing a child with a man whose name she refuses to divulge, the heroine of Nathaniel ...
-
Little Women
Louisa May AlcottAn Apple Books Classic edition. Meet the Marches! Louisa May Alcott’s classic introduces us to four unforgettable sisters: beautiful Meg, tomboyish Jo, delicate Beth, and Amy, the ...
-
The Good Knight
Sarah WoodburyDON'T MISS THE SALE ON THE NEXT BOOKS IN THE SERIES! When a king is murdered on the way to his wedding, Gareth & Gwen join forces in their first mystery together! Five...
-
The Wonderful Wizard of Oz
L. Frank BaumAn Apple Books Classic edition. You’ve seen the iconic 1939 movie, but do you know about the talking field mice, the Winkies, and the Witch of the North that appear in the original...
-
The Count of Monte Cristo
Alexandre DumasAn Apple Books Classic edition. Alexandre Dumas’ classic paints a portrait of Edmond Dantès, a dark and calculating man who is willing to wait years to exact his perfect plan for r...
-
Brush With Death
Mia HallMy first year at the Dreadmore Academy. What can go wrong? How long do you have? The list of stuff that can go right is much, much shorter.  I'm probably going to fai...
-
Sunrise at Crystal Bay
Mia KentA decadelong secret. A devastating betrayal. And a chance to return to the placeand the boyshe left behind. Leah Turner had it alla happy marriage of twentyfive years, two grown ch...
-
The Girls on Chalk Hill
Alison BelshamThey lie on the hillside, wearing matching white dresses, tiaras in their blonde hair. Each of them clutches a red rose. They could be sleeping, but frost shines on the lashes of t...
-
Become A Better Version of Yourself
Ben LeightonThis ebook contains golden nuggets on how to motivate, inspire and improve your current situation. It encompasses the holistic view of self improvement from mental& emotion...
-
The Next Girl
Carla KovachIF YOU ONLY READ ONE BOOK THIS YEAR, MAKE IT THE NEXT GIRL... You thought he’d come to save you. You were wrong. ‘ Absolutely the best thriller I’ve read this year! ’ Goodreads Rev...
-
Wormwood Abbey
Christina BaehrAs a Victorian clergyman's daughter, Edith Worms has seen everything until a mythical salamander tumbles out of the fireplace into her lap. When a letter arrives from estrang...
-
Wrong Places
Teralyn MitchellSometimes the path to happily ever after runs through all the wrong places… Romance never did Maggie Anthony any favors. So now that she’s back in her small hometown as a divorced ...
-
Winnie-the-Pooh
A.A. MilneAn Apple Books Classic edition. If you haven’t met Winnie the Pooh yet, stop reading this, and start reading the bookyou’ll be so glad you did. The jovial stuffed bear and his ragt...
-
Rascal
Katie McCoy"My hot new neighbor is keeping me up all night..." Discover the fakedating steamy romance, perfect for fans of Tessa Bailey, Elle Kennedy, and Hannah Grace! Emerson Haye...
-
The Grumpy Dinosaur
Michael GordonEmotions & Feelings Series Book 2 A little Dinosaur gets annoyed easily, sometimes for no reason at all! Anger is a normal, healthy emotion. It's OK to feel a...
-
The Duke Who Knew Too Much
Grace CallawayA #1 National Bestselling Regency Romance He's a rake accused of murder. She's the spinster accusing him. Enemies make the hottest lovers. "Readers looking for a goo...
-
Beautiful Darkness
Autumn GazeYou can have anything you want in life... You just can't have everything you want... Gareth is Fae. Sort of. His mother was a Nymph, and with that cross, he finds himself to b...
-
Silver Hunter
Lacey SilksThey call her a cougar, but he calls her, his Queen. Grace Brooks, Manhattan's most soughtafter hair stylist, never expected Hunter, the young handyman with a knack for fixing...
-
Teach Me The Ropes
Vanessa ValeMeet the Manning brothers in this steamy small town cowboy series from USA Today Bestselling author Vanessa Vale! A bachelor auction. I was in a fing bachelor auction. I wasn'...
-
Silent Scream
Angela MarsonsFive figures gather round a shallow grave. They had all taken turns to dig. An adult sized hole would have taken longer. An innocent life had been taken but the pact had been made....
-
Serendipity
Carly PhillipsHe’s from the wrong side of the tracks. She lived in the house on the hill. Now their fortunes have reversed…but their longago attraction still burns. From high school golden girl ...
-
Love Notes
Lexy TimmsWe're not here to take part, we're here to take over… I stood in the elevator, all my things in a cardboard box. Surrounding me, nearly every other employee clutched thei...
-
Boy Toy
S. E. LundTate McNaughton. 24 years old. Gorgeous. An artist independenly wealthy and the heir to a huge fortune. He's way too hot for my own good and seems intent on doing eve...
-
Against the Boards
Cynthia GundersonPeople say opposites attract, but now I have proof. There's zero rationale for why I would fall for Tyler Bowen. I mean, he's the star winger of my brother's hockey ...
-
The Art of War
Sun TzuAn Apple Books Classic edition. It’s believed that Sun Tzu wrote this Chinese military primer during the 5th century BChundreds of years before the Bible. The book’s 13 chapters ex...
-
Tongue Twisters for Kids
Riley Weber"Rubber baby buggy bumpers" Say this three times as fast as you can.  How about, try saying " Loopy lizards lying lazily aloft a little lane of logs,"...
-
The Hookup Equation
Roxie NoirTeach me everything. My whole life, I’ve been a good girl. I follow rules like nobody’s business. I obey guidelines like I was born to it. Show me a line, and I’ll toe it. I’m even...
-
Heartbreaker
Melody GraceDiscover the steamy smalltown romance now a USA Today bestseller! Perfect for fans of Elsie Silver and Lucy Score. They say that time heals a broken heart, but you try moving on w...
-
Ice Crown
Kay L MoodyThe competition could save her life... But only if she wins. Talise can manipulate the elements with ease. Water, air, earth, and fire all bend to her will. As a citizen of the Sto...
-
The Secret Diary of an Arranged Marriage
Halima KhatunWinner of the 2021 Bookbrunch Selfie Award for Best Adult I know I'll land a husband… but will he be the one? The Secret Diary of an Arranged Marriage – A Hilarious Romcom Tha...
-
When the Night is Over
Lily FosterAre the bonds of our first true love as strong as they feel when we’re young, innocent and consumed with the promise of forever? The last time Charlotte Mason saw Simon Wade, he wa...
-
A Tempest of Discovery
Sarah M. Cradit“Absolutely riveting!” "Cradit's delivery of mystery and intrigue is flawless." "Be still my heart. Nicolas Deschanel is back and better than ever." “A mus...
-
Protect Me
Margaret WatsonPolice officer Mia Donovan is studying for the detective's exam when her captain offers her an assignment – be Finn O'Rourke's personal bodyguard for the next three ...
-
A Light in the Window
Marion KummerowMargarete stumbles out of the bombedout house, the dust settling around her like snow. Mistaking her for the dead officer’s daughter, a guard rushes over to gently ask her if she i...
-
Game Changer
Piper LawsonA steamy, grumpy sunshine sports romance featuring a woman down on her luck, a star basketball player with a filthy mouth, and a connection neither of them can deny. After being du...
-
Dream Psychology
Sigmund FreudAn Apple Books Classic edition. Written by the founding father of psychoanalysis, Sigmund Freud’s 1899 book is the definitive text on learning to interpret dreams. Freud’s groundbr...