Transistor Definition and 494 Threads

Do transistors give a certain resistance? If so how do you find this resistance? Say Hypothetically for the following example. Refer to (fig.1). The resistor's value is 100Ω, source is 3V. Say if the transistor wasn't there, the amp would be 0.03A or 30mA. But when I run this in a simulation...

figure 1 shows dc model of CB transistor, why is it that collector diode is taken as current source in equivalent circuit, why not emitter is also taken as current source ?

I am having troubles understanding the working of a bipolar junction transistor(and also its uses as switch, amplifier, oscillator etc.). Can anyone recommend any good book or video explaining it?

Homework Statement Calculate the max collector current. Homework Equations Ic=BIb V=IR The Attempt at a Solution I'm not sure how to find the max collector current. Don't I need the source voltage to find my Ib and then use that to find my Ic? Is there another way of finding Ic_max? Also...

I know FET offers a very high input impedance..but what's the reason behind it? Is it due to the reverse voltage applied at gate with respect to the source which makes the P-N junction reversed biased? If that the case, what happens when there is no voltage applied at gate?

Unlike BJT, Why the minority charge carriers in FET do not participate in conduction? What is actually happening with the minority charge carriers?

Hi guys, I am trying to do this question on my own but i am not confident if what i am doing is correct. please download the Question2.docx file and my workings are in blue. hope someone can help me with this. 1. Homework Statement A. For circuit (a) below, calculate: R_e and R_C to make...

Today I learned how to tell if a transistor is NPN or PNP:

Homework Statement Firstly, this is more of a schoolwork issue, not coursework or a set task. It is more to do with understanding the circuit seen in the image provided: I am trying to understand why this circuit does what it is supposed to; activate the lamp when a certain light intensity is...

Hello people, I am working on a BJT NPN amplifier the model that I've choosen is 2N2222 : http://www.e-voron.dp.ua/files/pdf/tranzistor/2N2222.pdf I am having 3 problems here: 1) am not having any AC voltage at output Vce seems like I have set wrong operating point? 2) I am trying to figure...

In my circuits/active devices course we had to make amplifier designs with various type of transistors (BJT, JFET, MOSFET). In each design the transistor beta parameter played an important role in deciding which resistors to use in the final amplifier circuit. This beta parameter changes widely...

I need help in making my project using Bipolar junction transistor. I'm Engineering student (Ist year). Can someone here suggest me a Funtastic project that i can make easily and impress my teachers as well using BJT transistor. I have rea the Cascade, cascode and Darlington technique to amplify...

I was just sent an email with the following text. "" Here is a puzzle I just encountered. Take any NPN transistor and ground the base. Now apply +12 volts to the emitter through a series resistor of 1k. Yes, it is a Zener diode of about 6 volts so about 6 ma of current flows.What is the...

I would like to know a typical W/L value for a MOSFET transistor. L = channel length W = channel width/transistor width I am currently designing L to be L = 0.0001 cm for a transistor. Cox = 5nF mobility 1155 cm^2/Vs K = 0.583 mA/V^2 This gives W = 20 cm. But this is way to large for a...

I'm working on a project where i need to control an electromagnet but I'm not sure how to do it. I tried using a npn but the current passing through the magnet is just to small, should I use a mosfet instead. The specifications for my project say that they will provide us with 9 volts and a...

In the figure it could also be possible to connect the transistor Q1 as a diode by shorting its collector with its base ..but instead it is done by keeping both base and collector at ground... The text have to say that if it would be connected the other way(i.e by shorting collector and base...

Does the collector current in a transistor depend on the base-collector voltage in a common base configuration? If so,how does it depend mathematically?

Hello. I'm now studying transistor amplifier circuit and I have some confusion of definition of amplifier classification. I thought common emitter means emitter side is grounded, although there is actually some elements between emitter and ground in practice. So I thought "common" means...

Hello all, I am interested in measuring the photoresponse of a transistor with a fixed source-drain bias. I would like to feed the drain current into a current preamplifier and output the preamplifier signal to another location. The preamplifier has a very low current maximum, so I will use a...

I am looking at the Bipolar junction transistor, but I cannot seem to correlate with how the design would work for the CPU in terms of 0 and 1s. I am looking mainly at the transistor diagram from Wikipeida https://en.wikipedia.org/wiki/Transistor. Can someone tell me what Vcc, Vin, and Vout are...

Hello everyone..I have some difficulties in understanding the potential difference in a circuit with a transistor. Kindly refer to the picture provided. I understood that potential difference across Ry can be obtained from the formula in the picture. The potential difference across Rx plus Ry...

Hello. I've known that saturation current occurs when VCE is less than VBE, which means, the base-emitter is forward-biased and so it is for collector-base. For NPN transistor, electrons from emitter (majority carrier of emitter) is able to go up to only base, no further travels into emitter...

Hello I'm now studying current mirror and have a question about replacement of diode to transistor as shown in the attached image. The upper image is original current mirror circuit shown in study document. Collector current IC is very similar to current through Rbias thus current to load can...

Hello. Please look at the attached figure first, which is cut image from transistor section of HyperPhysics. In this circuit, I only need to know base current or base voltage, IB. In order to know this VB must be known but it is already given as 0.6 V. How this value is obtained? I don't think...

Hello. Let me think about the NPN transistor (Collector-Base-Emitter order). Here base-emitter voltage is forward-biased (The base is higher than the emitter in voltage.) thus current flow of majority carriers (Here they are electrons in N and holes in P) occurs from emitter to base. In next...

Homework Statement My teacher gave me a method to find Impedance of Thevenin and Norton. Here is her method: she removed Indepentdence source (voltage is closed, current is open) and did not put V external ( so the dependent source did not working because of no source). And she find resistance...

Does anyone have any papers or materials on how strong static magnetic field (7 to 12 Tesla) influence BJT and MOSFETS? I didn't find many people doing research on this. All I find is some experiment results. It seems transistor parameters change a lot with different azimuth angle due to Hall...

hello im so overwhelmed with this topic , I am supposed to understand the common emitter setup of a transistor , and i really can't ! , my textbook is full with terminology and concepts that i haven't studied before ( which doesn't make sense ) and that's why i got stuck with this lesson . i...

Hello As I read all the above links of Wikipedia about HEMT I have many problems to know better about these kinds of transistor.could you introduce me a good tutorial about HEMT transistors? Thanks

Homework Statement Consider a 2N3904 NPN transistor in a circuit. Treat the lightbulb as a 100 ohm resistor. For different values of R, what is the current through the lightbulb? Enter two digits rounded to the nearest 0.1 amps. If R=500 ohms, the current through the lightbulb is: If R=5...

Homework Statement https://www.circuitlab.com/circuit/8ekkzw/dfsgadsfgdafgh/ For the circuit, suppose that the input voltage V_in is a superposition of 18 V DC and a sinusoidal component with a 6 V amplitude (thus the input voltage varies between 12 V and 24 V). Diode D1 is a 4.3 V zener...

Hi everyone..I'm trying to build a Joule Thief circuit operating on a 1.5V cell. Which transistor should I use? I have BC547 but I'm not sure it will work...Suggestions are welcome..

Homework Statement I am doing a project on the Elenco AM/FM superheterodyne radio kit. I have been stuck for ages trying to figure out how the two common emitter amplifiers are tuned to filter out anything that is not around 455 kHz. I tried to find a bandpass filter, or a high-pass and a...

In the given circuit Q2 is a current buffer tranistor which maintains constant current voltage for Q1 just to cancel the harms of early effect...how does it do so??

Homework Statement Calculate Rs so that the draincurrent ID = 4 mA. Vad does the gain A become? uo/ui? For the transistor: k = 3 mA/V^2 Vt = -2 V also: R1 = 50 k ohm Rd = 2.2 k ohm C = infinity for signalfrequencies image of circuit...

Homework Statement we look at a silicum n++ p+ n transistor. given: NE= 1,0×1018 cm–3; NB= 2,0×1016 cm–3; NC = 2,0×1015 cm–3; here E stands for the emitter, B for the basis and C for the collectorHomework Equations a. calculate the distance in eV from the fermi-level to EFi for the emitter...

I need to know if my formula's are correct for current gain. Sorry for shakey drawing. I know beta would change the dc values slightly but for my prof. it's close enough. Beta AC = 70. DC Analysis VB = R1R2/R1+R2 VE = VB - VBE IE = VE/RE AC Analysis r'e = 25mv/IE Req = R1 || R2 Rout = RC ||...

hi, my name is suli, 16 year old from living in the U.S. I want to one day become as decent an engineer as i can, i hope that this site will help me learn more about the rules that govern the universe. i am especially interested in electronics, maybe its because of iron man ? dunno... well...

My teacher gave me this picture below. My question is why Io go through Rc but does not go through C2

Hello, in a small scale project I need a way to get 7 outputs from 3 inputs, I have an idea how to do that using transistors but the cost adds up due to the high amount of transistors, it would simplify things space wise, and cost wise if I could eliminate the NOT gates, is there such a thing...

The npn transistor is said to function as an amplifier only in its active state (emitter base is forward biased and collector base is reverse biased). It is considered that majority of the electrons reaching the base layer is dragged into the collector layer. So the emitter current (ec) is...

Hi, I'm planning on using a mosfet with my raspberry pi to controll a circuit, using the GPIO pins which can be set to +3.3V or GND but I'm having problems with choosing the type of MOSFET I will need. I've found the data sheet for a possibility here http://www.diodes.com/datasheets/ZVP3306A.pdf...

Hi, I'm looking for a device like a transistor which preforms the opposite. E.g. On an NPN when Base is +0.7V current can flow through the Collector to the Emitter and when the voltage at B is 0V (i.e. a switch connected to base is open) no current will flow from C to E. I want the opposite of...

Are there simple governing equations for FETs like there are for BJTs, and if so, what are they? For example, in the BJT case we have IC = β×IB IE + IC + IB I'm sure it depends on the type - MOSFET, JFET, etc. - so anything anyone could contribute would be helpful. From what I understand, the...

I have a simple conceptual question rather than an actual problem so pardon me for not using the provided template. There's a question in my Microelectronic Circuits book involving this circuit: where it states that Part of the solution involves this equation: VOV4 = VD4 - VS4 (equation...

So, recently I started learning about electronic components and then I started learning about semiconductors. The one which I've been having some real trouble to understand its function is the transistor. So I bought an electronics textbook called El ABC de La Electrónica (The ABC of Electronics...

Hi i have have a small question regrading to a NPN BJT transistor. the DC current gain (beta) is the ratio between Ic/Ib where Ic and Ib are the collector and base currents respectively. Ib is the input current, that's alright , but, i don't get why Ic considered as the output? in NPN BJT...

The title already said the question of this thread. As I searched the internet, transistors were configured in common-emitter configuration. They also show me that in order to activate the relay, the transistor should be operated in saturation and cut-off mode. How to make my BC547 Transistor...

I would like to know why the threshold voltage increases for an NMOS transistor when the voltage difference between the source and the body terminals is greater than 0. If, for example, the body terminal is connected to -1V and the source to 0V, holes from the p-substrate are attracted to this...

I don't understand the condition of saturation in an npn transistor (common emitter config). My textbook says that the collector-emitter voltage reduces to near zero upon increasing input voltage. Also, Wikipedia says that both BE and CE junctions 'become' forward biased. Can anyone please...