Transistor Definition and 494 Threads

Homework Statement In circuit (figure), there is negligible potential drop between B and E, where β (current gain) is 100, calculate (i) base current (ii) collector current (iii) potential drop across Rc (iv) Vce (Ans: 11.25 µA, 1.125 mA, 1.125 V, 7.875 V)...

I want to learn how a cascaded common emitter transistor amplifier is modeled. I also want to know how all the calculations are done with regards to current and voltage gains, input and ouput impedances. I want to also know how we do the calculations with and without the emitter reistor. Can...

Homework Statement List at least five methods by which a transistor can be used as a diode. Homework Equations N/A The Attempt at a Solution I know three configurations viz. Collector Emitter Short, Collector Base short and Base emitter Short.. What would be the remaining two...

hey! friends i have to construct a two-ways switch. Can i use a transistor in that case. i means i am constructing a R2R ladder DAC circuit. in that circuit, there is a switch in two ways- originally ground and connect to ref voltage when switch is on. Please suggest me, which device is the...

does anyone happen to know what resistor i would need for a pair of 850Mah rechargeable batteries as the one in my hair clipper burnt out when i replaced the old rechargeables which were 300Mah cheers

What is the requirement to turn on a transistor. I always thought Base-Emitter junction should be forward biased. But I was looking at the TTL inverter and in that ckt, the collector of one transistor is connected to base of another transistor. How do you find out the voltage on the collector...

Hello everyone, I'm just getting started in studying radio frequency design and have a question about amplifiers with a tuned circuit as the load. When setting the operating point of a standard class A transistor amplifier with a resistive load, one uses the collector resistor to set the...

After doing some research, I am still confused is a transistor a switch or an amplifier. If it can be used as a switch how do I find the part that will work with the gate voltage that I give it. mouser.com wasn't really helping me in finding the right part.

I have been searching for a generic model of MOSFET/BJT transistors for Capture CIS. I would like something where I can easily edit K, V-Threshold, and B_f (beta-f) without messing with channel lengths and widths and such. Does anyone know where I can download such a thing?

Hello everybody, I'm currently taking Electrical Engineering as senior physics major at Fordham University and have decided to take on a little side project to gain a better understanding. What I'm attempting to create is my own Transistor Logic -> RS-232 (Rs-232 refers to the serial...

Can anyone explain to me what is the significance of a chopper transistor as opposed to a normal BJT? I read online that its used for square wave pulse generation, but I don't really understand what the mechanism is. Thanks

Hey guys. Can someone help me with this circuit? http://www.discovercircuits.com/H-Corner/secwireloop.htm Where it says "beeper" do they mean a speaker or do they mean a buzzer? And can I replace the 2N7000 transistor with a 2N3906?

"Transistor Action" Dear Forum, I have a question about what is often referred to as "transistor action". I understand how a transistor operates within a circuit, and the characteristics of such a circuit, but I would like to learn physically how the bipolar transistor is able to control...

In my circuits class we were talking about bipolar transistors and our prof. mentioned that every bipolar resistor has an intrinsic emitter resistor. So, I tried modeling a couple of circuits in SPICE to see if I can replace the transistor with another circuit (voltage source, current source...

Homework Statement Here's a crude description of the problem until my attachment is approved: it's essentially a voltage divided connected to a common-emitter amplifier (I think). There's a +10 V line connected via an 8.4 kOhm resistor to the base of the NPN transistor, and a 1.6 kOhm resistor...

Hi - I am looking for an NPN transistor with the lowest Vbe I can get. Any suggestions for specific transistors? (rather than a material class i.e. GaAs) I only have 3.1 volts on the collector and the emitter voltage has to be above 2.5 volts to get a circuit to trip. So 3.1v - 0.7v =...

Question about Walter Brattain’s “field-effect transistor principle”. The Wikipedia says “On 17 November 1947 John Bardeen and Walter Brattain observed that when electrical contacts were applied to a crystal of germanium the output power was larger than the input.“ Can someone please...

**Transistor radio/kWh problem** A transistor radio operates by means of a 10.0 V battery that supplies it with a 48 mA current. (a) If the cost of the battery is $0.55 and it lasts for 300 h, what is the cost per kWh to operate the radio in this manner? 3.819 dollars/kWh...

Hi Is there any one, that can explain how a potential effect transistor, PET, works? I would like to know how the current is controlled by changes in the potential. Thanks

Can anyone explain about or point me to any articles about using transistors as zener diodes ? Why not just use zeners, and what connections (c-b short or e-b short) and their pros and cons ?

Homework Statement Showing how to get: Z_{out} = \frac{Z_{in}}{h_F_E + 1} from \Delta I_E = \Delta V_B/R Homework Equations \Delta I_E = \Delta V_B/R Z_{out} = \frac{Z_{in}}{h_F_E + 1} \Delta V_E = \Delta V_B The Attempt at a Solution I am trying to prove...

A bit confused about how it works. Link - http://www.technologystudent.com/elec1/transis2.htm (3rd fig from top) The way I understand, transistor TR1's Base-emitter conducts, which fwd biases B-E junction of TR2. This in turn will turn on the lamp, but it won't be really bright. Once its...

Hey everyone, In my EET program we're going over AC equivalent transistor amplifiers. We've gone over how to do some of them in class but I can't seem to figure out how to find roe. I have the output characteristic of our 2N2222 transistor and made the DC load line but I'm not sure were to go...

Hey, I would like help understanding this scenario: (1) base-collector voltage, V_BC, is reverse-biased (2) base-emitter voltage, V_BE, is forward-biased (3) collector current, I_C, is negative Normally, if I_C was positive, I would assume the transistor to be in the forward-active...

Homework Statement http://img300.imageshack.us/img300/2640/17569077cy5.jpg The transistor is a N-P-N type. When the siren is functional, the resistance of thermistor is 120 ohm. R1 is 600 ohm. The question is "Calculate the collector current if the emitter current is 100mA". I know that...

Homework Statement hello guys I have an assignment to "Explain six transistor characteristic curves using the construction and operation of BJTs" I searched all over internet but couldn't find any article relevant.(i found lot of articles about characteristic curves but none of them...

Homework Statement In my electronics practical class, i assemble a ckt of amplitude modulation using BC107 transistor ,but the modulated wave always has the same phase up and above , there is no phase difference b/w the upper and lower part of the wave . My teacher also couldn't...

In the midband region the voltage is constant and is assumed to be unity and the transistor amplifier is always used in this region. Doesn’t that mean that there is no voltage gain??

I'm currently using this circuit, but without the rectifying portion,a audio source from mp3 player instead of a mic, and a 4V LED instead of a bulb. My power source is 12v. However, the voltage across the LED is only around 1-1.5V. How can i increase the voltage across the LED? Here is what i...

i have been trying to solve this problem for about 14 hours and have gotten nowhere, I am trying to figure out the voltage going into the base of an npn transistor, I am trying to build a circuit where i can take the current from the battery and build a circiut from 7npn transistors in a common...

ive been reading about transistors and i have a question i can't find answer to, maybe someone here knows the answer. how much current can a transistor amplify or create? for example, can you push 1 amp of current through the collector of a 15 amp 12 volt NPN transistor and would it boost the...

Homework Statement circuit diagram showing what has been identified as an NPN transistor with the collector and base connected to neg and emitter conected to pos. The base is also switched by a photodiode and the emitter is supplying a light bulb.Question asks when will the light come on.Can...

The question being referred to is question 3 on page 8: http://www.itute.com/physicsline/phys_trial_exam1_2008v2.pdf Answer referred to is Question 3 Area of Study 2: http://www.itute.com/physicsline/phys_trial_exam1_2008v2sol.pdf I don't understand why they get this answer. The answer I...

Is it the voltage divider and/or the Rc resistor that is responsible for biasing an NPN transistor. I am aware the role each play, but was just wondering which part actually biased the transistor, i wouldve thought both?

Sorry i couldn't get a copy and paste of the question, but it is as followed on the link: http://www.vcaa.vic.edu.au/vce/studies/physics/pastexams/2006/physics1w06.pdf Question 3 on the electronics section, page 13. I got no ideas how to solve this. I wouldve assumed that there would be...

i have to submit a report on the characteristics of a transistor. there's three zones blockage zone saturation zone and modulation zone i understand the first 2 but the modulation zone i couldn't find out what it is please help if you can thanks

Homework Statement What does a capacitor across the base and collector of the transistor do? Apparantly adding a cap (1uF) will slow it down. Can anyone explain how? Homework Equations The Attempt at a Solution

Hey guys, sorry to keep posting things about the NPN transistor but i think I am starting to understand it. I was just wondering if you could confirm these facts for me: 1. An external powersupply is needed to turn the transistor on (by forward-biasing the emitter-base junction), or by using a...

I want to amplify the current/voltage from a music source. Specifically, I want to use the varying signal to vary the light intensity of a system of LED's connected in parallel. Basically, I want to create pulsating LED's. What I'd thought of was using a sound signal from my ipod to do so. I...

Here is the problem: The PMOS transistor in the figure is conducting current. (a) Is V_TP > 0 or V_TP < 0 for this transistor? (b) Based on the value of V_TP, what type of transistor is in the circuit? (c) Is the proper symbol used in this circuit for this transistor? (d) If the symbol...

Just curious. For some odd reason, I don't seem to get it.

what is the impact of the temperature on the characteristics of NMOS transistors?

what base-emitter voltage is needed for a current to flow through the trasnsistor?

I use my computer a lot for watching movies and at night i really don't like getting up and having to manually hit the power switch, so i was thinking it could be possible to do it wireless. Now i have a general concept here, maybe an IR reciever going to the base, a line feeding from...

Greetings Can somebody please help me understand the use of transistor as a switch and that as an amplifier?

What's about this? Where a capacitor is between base and collector (NPN). I have formulated some of my own theories (it seems like this is totally unknown of on the internet, and the books I've looked at don't explain it), but I have thought of flaws to all my theories. Can anyone please...

Homework Statement an npn transistor is used to drive a constant current I through three ‘white’ LEDs, connected in series. If the required current value is I = 25 mA, and the current-gain of the transistor is β = 300, find the value of the resistor R, giving your answer to 3 significant...

Alright, I've been stuck on this problem for my electronics class for far too long. " Design a CE amplifier with a gain of 10 using a 2n3906 transistor and a 20 V power supply. Calculate the required resistor and capacitor values for the circuit, assuming a minimum frequency of 10 Hz." It...

Hi guys, I need to build a REALLY simple amp for a friend. I only want to use a resistor and a transistor plus the normal stuff(battery and speaker). Please help. Thanks in advance, Circuit Man

Homework Statement Consider a PNP Biploar Junction Transistor uniformly doped in each region. Sketch the energy ban ddiagram for the case when the transistor is biased in a)In thermal equilibrium b)biased in the active region c)biased in the cutoff (depletion) region Homework...