Transistor Definition and 508 Threads

The circuit is shown below and i am asked to find out the voltage gain A(v) Beta = 100 and Vcc = 13.7 volts Common emitter configuration. Voltage Gain is equal to the ratio of output voltage to input voltage . The Attempt at a Solution Don't know how to proceed as there wasn't...

I just had arguments with my teacher about my test answer in class. I'm a little upset, but maybe I'm acting like a spoilt brat (I'll be the first to admit it) I went out and I'm using a hallway computer in my college so I can't post images. I still disagree with him-- But I'll try to explain it...

Conduction in reverse biasing too?? Is it the case with transistor?? I have a mechanical analogy of diode in which a socket is provided with a one way valve. (figure 1st below). The arrow inside the circle shows the direction of motor pump. When there is enough pressure to lift the valve...

Homework Statement See attachment. Homework Equations Voltage division equation. Ohm's law. The Attempt at a Solution From a) I know that Rx = 86k ohms. Part b) and c) befuddle me. I think it is relevant to the transistor being on and off. In b) I would think that because Rx...

I know this question is very vague, but my textbook, amongst various websites/videos, tend to discuss what a transistor does (amplify/control current) rather than how it does it. I know current IC and IE (collector and emitter current) are controlled/proportional to a base current that flows...

Hello All, I am a Masters student in Microelectronics and stuck at something very trivial. In implementing Pass transistors using K Map, i am facing some probs. For eg. consider the function bc(bar) now if you draw a k map the left downward 4 blocks will be filled with 1s. I don't understand...

Rc= 5k ohm R1=100k ohm R2= 27k ohm Re=3.3k ohm beta=200 Vs=12.7V Vce= 0.3V at saturation With no signal applied, dc voltage btw collector ans ground measured as 7.7V Calculate the transistors base,emitter,collector currents Ive only come across problems with transistor in linear...

http://img252.imageshack.us/img252/6080/photo46k.jpg Once the transistor is at cut-off, it means Ib and Ic = 0. I don't see what the diode has to do with anything in terms of "protecting" another component. Can anyone help me see that?

Hello, I need to know that... how to select the MOSFET for Low Voltage(40v) and High Frequency (3-4MHz) ? Which MOSFET is suitable for those specifications ? Please give me the reply...

Hi guys. I learned that you need to apply DC biasing to establish your transistor's amplification zone. Some weeks ago I was struggling (as almost we all do with anything related to E.E.) with transistor amplifiers. I had to make 3 amplifiers with 3 different biasing configurations. I...

hello my friends i searched a lot in the internet and i couldn't find my answer.could you tell me what is exactly FT do in transistor? what are the formula that join ft to another transistor elements for designing an oscillator or mixer? if good book tell me more i will appreciate you. i...

I'm trying to understand working of transistor( common emmiter ) and there is one line that i don't understand and i ahve found that line in many books :- " A small change in base current controls the larger collector current" . I don't understand how the base current controls the collector...

In a transistor... If a question asks me to find Vb, do they mean the voltage from the base to the ground, or the voltage on the base resistor? The question I have does not specify, it just says "find the base voltage, Vb" So I have 2 Vb's and I'm not sure which one they're asking for...

I am working with a kit circuit that I ordered online. The circuit triggers a relay when it "hears" a loud noise. I am going to hook the relay to a strobe to capture the moment of impact. with my camera. The circuit by design triggers and "holds" the signal until it hears it again. This will...

Is the output from a transistor sensor circuit analogue or digital? I know that you sometimes need a pull up or down resistor due to a very small current flowing through the transistor even when it should be off. However, in the circuit shown below for example, is the output signal analogue or...

Homework Statement The circuit has two transistors 'Q1' and 'Q2' as shown in the figure with 'Beta1'=100 and 'Beta2'=50. The circuit figure is shown below and Vbe1=Vbe2=0.7 volts. Need to calculate I1,Ib1,I2,Ib2,Ie1,Ic1,Ic2 Homework Equations The Attempt at a Solution

Hello! I have done some research on transistors because I want to increase my current via increasing the voltage of a circuit in order to offset the increased load. As far as I understand, transistors can amplify (increase) voltage and current, as well as rectify (does this mean it can convert...

I'm trying to convince myself that the circuit below will compensate for temperature-dependent changes in VBE. But I can't seem to figure out what the collector voltage of Q1 is. Even if I assume a base voltage of 0.7V, the base current is still unknown (to me at least) so I can't calculate the...

Homework Statement Why does a transistor with a constant V_{B} (e.g. V_{B}=1V) only need V_{C} \approx 0.3V to act as a current source; If V_{C} < V_{B} doesn't that mean the transistor is not in forward active mode and thus not a mode we want to work in. Homework Equations The...

I need help on how to cascade two or three Jfet transistor and the calculation of the values to have a good amount of gain. The cascade also should help in providing good linearity, have less distortion and should stable good stability.Thanks, good help will really be appreciated by me.

I am having a hard time to find answers to 2 simple questions regarding semiconductors. Firts, at a PN junction diffusion creates a potential step. Why can this voltage not been measured from the outside. The schoolbook answer is, that there are diffusion potential at the wire connections...

Hey guys I am playing with my new oscilloscope i got myself with income tax, and ran into a puzzling question. I am trying to generate an inverted pulse signal, and while my transistor is saturating quickly (driving the output to ground), when i turn the input signal off, it takes its sweet...

I am trying to determine the mode of operation for the following circuit and find the voltages and currents: I am given that β = 50 I know that VEC > VEC,sat for a transistor in active mode I applied KVL on the right loop and got: VCC = 300Ic + 1000Ic + VEC VEC = VCC - 1300Ic i'm...

Homework Statement Hello all, I have the following logic gates: (A'.(B+C))' which I had reduced to A+B'.C'. I then want use a NAND gate connected to a NOR gate, then connected to an inverted. However, I have been informed that I need not to use ten transistors, and that 8 can get the job...

Hello, I've just been playing around with a 2n3904 transistor and 3V coin battery. I noticed when powering an LED with a transistor switch the LED is significantly dimmer than when powering the LED directly. Why is this? Is it because 0.7 volts is siphoned off just to turn the transistor on?

Hi all, I was working with an emitter follower circuit similar to this one: http://upload.wikimedia.org/wikipedia/commons/b/b8/NPN_emitter_follower.svg , the only difference being that in my circuit, there is a 100kΩ resistor between the Vin site and the transistor. RE is also 100kΩ. I...

Homework Statement Determine the voltage level at V3. For each case also determine which transistors are on and saturated, on and active, and which are off. Let R1=R2=R3=2.2kΩ and let Rc=240Ω and Vcc=5V. Calculate β for each transistor as well. We are to assume that if the transistor is on...

Transistor Switching with the Arduino I know nothing about electrical engineering.. I have a TIP3055 NPN Transistor rated at 60V and 10Amps .. I have 12v 2amp current coming off of a "power supply" that's plugged into a regular american grounded wall outlet. The 12v is plugged into the...

I came up with this doubt last week. Consider a NPN transistor. Usually we bias it so that current enters through the collector and base, and leaves through the emitter, right? That allows the base to form some holes, which recombine with the electrons emitted by the emissor and that way the...

Background: I am building a giant clock with four, multiplexed, 7 segment displays. The problem is that the displays are five inches tall, each segment consists internally of 10 LEDs wired in series and then three chains of 10 are wired in parallel. The datasheet for this chip is here (PDF...

If you know how a single electron transistor works, can you please explain to me what the tunneling junctions are necessary for? I mean, if we would remove the two tunneling junctions and connect the drain, the source and the island into one long wire, wouldn't still it be possible to create a...

I am wondering how I would create a really simple electronic calculator/computer

Confused about transistor "saturation" region I don't understand why the saturation region is called the saturation region. Take a look at the graph below: According to that graph, the "saturation" region is where the current changes most rapidly, which is the exact opposite of the...

Hello. I have been running some simulations on CMOS inverters. When I change the channel dimensions, I noticed something interesting with the drain current -- the smaller the channel dimensions (say around 3μm x 3μm) the simulated drain current is very close to the predicted theory drain...

Hello, I posted this here because it is for a bit of course work, but I am just looking to confirm if I am using the right equation. I hope this is ok! If not, sorry! I just didn't think since I was asking a specific assignment question, I would post here. I need to investiage how changing...

Homework Statement Just started learning about transistors, and I am having difficulty doing this problem. The transistor in the circuit has k_n ^'=0.5mA/V^2, V_t=0.5 V, \lambda =0. Show that operation at the edge of saturation is obtained when the following condition is satisfied...

Early effect states the collector current increases as we increase CE voltage in a common emmiter circuit due to base-width modulation. But how does the Early effect change the base current? Does base current remain constant or does it change?

Homework Statement You want to use a PIC microcontroller to drive a motor in a clockwise direction at either 0% speed (when the PIC output is 0V) or full speed (when the PIC output is +5V). This motor draws 500mA at +5V while the output of the used PIC is limited to +5V and 20mA. To solve...

HI FRIENDS Is there any substitute of IC 74192 and low power MPSA 14 NPN TRANSISTOR I Cat`t find that in my country. thanks

I'm currently studying transistor amplifiers and It is not entirely clear how impedance relates to amplification. For the emitter follower configuration, the book I'm reading implies that low output impedance means high voltage gain and, for any amplifier in general, high input impedance is...

Consider this picture, a) and b). [PLAIN]http://pokit.org/get/f0af323a103c1d29539836143a7784a1.jpg Now I am getting confused a bit here. a) I know that the first picture represents a bias for current source. And we change the value on the potentiometer the current will stay the same...

Hello, So this thread is about using transistor as a current source. I understood the concept and all. But the main point of this thread is to finally seal my knowledge of transistor in saturation mode. We did an lab exercise about current sources, by biasing transistor with voltage divider...

Hello. As the title says, I need some help in getting a transistor to amplify a current. I have a TIP120, whose DC gain is specified as 1000. I am applying a positive voltage of about 0.6 V to the base. The current is around 10 μA. I have the positive side of a AA cell connected to the...

Sorry I'm jumping from one problem to another, I just have plenty of time today and I got my scanner :smile:Homework Statement Find Ic, Ie, Ib (circuit drawing and data in the solution) The Attempt at a Solutionhttp://img263.imageshack.us/img263/3285/findcurrents.jpg Is that correct for Ie...

What is the meaning of differential gain? Iam studying a document that says, opamp can provide differential gain unlike transistor. I don,t know what does it mean. Can some clear me out. More, what is meant by bias volatge in case of op-amp. I am very beginer to electronics.

Help me on transistor ! What is the difference on NPN and PNP transistor ?

Basic electronics problem with an "amplification factor for a transistor" ((I think it still counts as "introductory physics" -- let me know if I'm wrong!)) Homework Statement http://img600.imageshack.us/img600/7950/back1j.jpg http://img690.imageshack.us/img690/999/back2wzt.jpg...

Homework Statement I want to know how to arrive at the equation for the base emitter side and collector emitter side of a transistor using kirchhoff voltage law. Homework Equations Kirchoff voltage law is \sumV = \sum IR. Please refer my attachment in which i have to arrive an equation...

Homework Statement 1. Additional Exercise 7 in the textbook (H&H, p. 110). Vout is 0.5Vcc at the quiescent point. You may assume beta = 100. The transistor is said to saturate when VC = VB. Use the fact IC grows 9%/ degree C and that VBE is constant to determine when the transistor...

hi i would like to bias a transistor into cutoff. i have the schematic shown below and for the transistor i am using it has a collector cutoff current at 100nA. so my approach was frist to perform Dc analysis: Vth=5*(R10/(R10+R4)) Rth=(R4*R10)/(R10+R4) so my input equation is...