Transistor Definition and 494 Threads

Hi, I'm trying to set up a PNP switch that looks like the attached file. However, the only way I can have the load be completely off is if my 'chip output' is >>5v, only if it's = to Vs. I'm new to this, help would be appreciated. What should I look for when picking out a transistor so...

Homework Statement Find IB, IC, IE, VB and VC in Figure 7, where Bdc is 40.The Attempt at a Solution VCC-ICRC-VCE=0 IC=BdcIB VBB-IBRB-VBE=0 IE=IB+IC VBE=VB VCE=VC

In the circuit attached, when S1 is down, a sound is emitted from the speaker. When S3 is down(connected) a lower pitched sound is heard. When S3 is up and S1 is up, a high pitched sound is heard. I don't understand why the pitch changes in those settings, and I also don't understand the purpose...

I need some guidance on this question, and possibly a check over my attempts? I'm not exactly a star Physics student. Help is much appreciated. Homework Statement [PLAIN]http://img835.imageshack.us/img835/8124/ques.jpg 6) Label the above transistor. 7) If switch S is opened, the bulb only...

i am tring to use transistor tip 41c , and i want to calculate Ic ,,, knowing that ( Ic=B*Ib) but when i try to know BETA (B) from the data sheet of the transistor i found that it vary with the collector current (Ic) and the graph show the relation between (Ic) and beta in case Vce=4 volt...

[PLAIN]http://img256.imageshack.us/img256/2164/transistor.jpg i should find Re so that transistor works in saturation region also i should find Ib in saturation region Rc=2kΩ , R1=2kΩ , EB=5V, Vcc=10V, V1=3V, β=100 im really confused with R1 and V1 i don't know what is their function i...

hello friends. i my book its said that both these transistors are in parallel . but i didnt understand it... how can we say that they are in parallel ? thanks ...hopin for help.

Homework Statement Estimate the collector voltage VC when vin is +1, +2 and +3V. (assume IC/IB = 1000) Homework Equations IC/IB = 1000 The Attempt at a Solution I know that a transistor becomes saturated when VCE and RCE are reduced to 0 and when the maximum IB flows, but in...

how to understand each sub grap all those lines inside http://i46.tinypic.com/124j3hd.jpg

[PLAIN]http://img687.imageshack.us/img687/2164/transistor.jpg is this a pnp transistor? if yes, why does the current go from top to bottom? also, does this transistor work? I mean shouldn't there be 0 current going throuth the two resistors? i can't understand it at all

I am studying the design of an amplifier in common emitter configuration. I am studying from microelectronic circuits by sedra and smith. the author has described two terms for gain of a amplifier. one is the represented by Av and is called the voltage gain of that amplifier and the other is Gv...

why we over dope one side of the transistor why it lookes like N+ P N why not just N P N ?

Homework Statement revered members, in the following attachment, i could work out the path of current in pnp transistor, that is, from base through RB AND THE output is taken across RL. but i can't figure out the path of current in npn transistor. could u please help? Homework Equations...

I am having great trouble in understanding the operation of transistor in saturation region. This is how I understand the working of a transistor: In a bipolar junction transistor the width of base is very small therefore very small number of carrier undergo recombination inside base, whereas...

Homework Statement I have A transistor Circuit As shown in the figure. I want to find out the current in all branches that is I(b), I(c) and I(e). Homework Equations As far as I know, the equation I(c) = β * I(b) is only valid when I(b) is less than certain critical value called the...

in pnp transistor after some time on increasing voltage why the current become constant ?

I am looking for help on a schematic for a 12 transistor CMOS SRAM cell shown below. I understand how to implement the inverter and transmission gates and how a tri state inverter works, but I am confused when it comes to inverting the input of the buffer and how to tie it all together. Thanks...

Hello all, I have been trying to simulate a circuitry involving a transistor for the microphone line. I believe it was used for amplication of the external audio signal (not too sure, maybe can share the circuit). I am using the ADS to simulate my circuit. The problem I faced was the...

Hi, I am new here, I'm still in high school here in Melbourne Australia, so please excuse my stupidity. Theres a question come up on a massive project that has a large bearing on our end of year results, its got to do with clipping of an output signal, and relating it to the Supply voltage...

Would someone be kind enough to explain what happens to the operation of both transistors in both the positive cycle and the negative cycle of the input signal please? I'm having a hard time understanding how this works exactly. What I know is that with no input signal, both transistors have a...

I have a small problem regarding darlington transistor pairs. Lets say a source is connected to the coupling capacitor Ci and this source has an internal resistance of for example 10kOhms. When finding the Output resistance of the darlington, should the internal resistance of the source be...

Hello, Thanks ahead for fielding my amateurish question - I'm a math guy and circuits are new to me. I'm trying to design a quick & dirty (aka need-not-be-linear) RF amplifier circuit and was wondering the following stupid thing: A lot of the circuits I've found are configured for NPN - if...

What is the smallest switching time of a transistor ? ! :confused:

What would be the best configuration for amplifying output from 555 timer chip? No matter what transistor configuration I cannot get it higher than 30 mA (I am shooting for 200 mA). Thanks

http://img118.imageshack.us/img118/6515/circuitf.jpg Theres the circuit i have. Vdd = 10 V, Vtn = 2 V, Kn = .22 mA/V^2, Rg1 = 1.01 Mohm, Rg2 = 1.06 Mohm, Rd = 6kOhm, Rs = 5kOhm. Im trying to figure out how to compute the drain current Id. As well as the drain voltage Vd and the source voltage...

I've been doing transistor operation in college and I've got pretty confused in some places...please see if you can help me out... 1. The collector-emitter leakage current flows only in the common emitter configuration,when the base current is zero. Could anyone please tell me why the...

base current in transistor flows due to recombination of electrons and holes. Explain

Dear Experts, I am using a NPN transistor part number C33840 (i think aka BC338-40). The collector is tied to Vcc @ 12V. The emitter connects directly to the capacitor of 1000uF. The base is supplied with a small current of about 0.9mA (1 LED) from a 1k resistor (in series with the LED)...

Hello All, I have very basic questions with respect to what we mean when we say a Transistor is in "Saturation". As I have read almost everywhere, we need to Forward bias both the emitter-base junction and Collector-Base Junctions for transistor to go to Saturation. Before I post my...

i want to protect my transistor(working in saturation) from high incoming voltage... can a diode be used to protect it from the high voltage?

Does anybody happen to know what it is, or how to find out the voltage drop of a particular transistor?

Dear Experts, Hope all of you are enjoying the holidays so far. I am newbie dabbling with circuits to make something for myself. recently, i made a pulsing signal go into a NPN transistor trying to amplify the output required to drive some LEDs using the transistor as a switch. I know...

Hi, I'm learning Bipolar Junction Transistor and need help to confusion which arise so I will keep posting questions which I don't understand to this thread. Thank you in advance. So my questions start: When using hybrid pi model and t model, we determine the dc operating point first. In one...

I've got these two BJT circuits. I want to know if the result are the same. Are both circuits below same? Can the bottom left resistor be grounded and be same as the second circuit. http://img21.imageshack.us/img21/2886/bjtt.jpg

I'm designing a circuit for a nixie clock and I seem to have two options for how I want to turn on the nixie. http://img16.imageshack.us/img16/9181/circuit3l.th.jpg The circuit on the left is what I originally prototyped and it seems to work fine; however, my friend has suggested that I try...

Transistor AMPLifier HelP ! could some1 explain it entire circuit in terms of electron movement i.e how the voltage drops in each component in terms of electron flow 1)i can't understand the voltage divider bias i find it extremely difficult please explain it interms of electron movement in...

Im working on a project that involves me making a electrical circuit that will supply initially around .52 amps of current for and then drop the current to at least .40 amps of current to a actuating wire that uses current to cause wire to contract. The way i have my circuit made is that i have...

Transistor AMPLifier HelP ! i will start from the first please clarify my doubts i will post my other doubts as and when i get replies and answers my first doubt is what is meaning of Vbe base emitter voltage and also Vce collector emitter voltage what is the actual meaning of these...

this query was previously in electrical engg; later i found that it actually have to be solved as a solid state physics one. (as in books) In an n-p-n transistor, emitter grounded, electrons enter the emitter from ground , where 90-98% come out of collector, and rest go out of the base. In...

Homework Statement I'm interested in the difference between the way a transistor amplifier amplifies with DC and with AC. I know that a transistor amplifier connected to a DC voltage source will have a larger gain with a bypass capacitor than without. Is this also the case when connected to...

This is a homemade failure and i need to find out how is the transistor damaged after summited to these 3 tests: test 1. base: pump in correct Vbb emitter: grounded collector: open test 2. base: open emitter: open collector: pump in correct...

i can't understand the transistor completely i can understand how it works but this stupid conventional current is confusing me completely please can anyone give a lengthy explanation on working of transistor CE CB CC types. i don't understand all these types of transistor i.e how current...

If we make an NPN transistor and change the base doping level so that we get a higher consentration of holes will β increase or decrease? Why? I know β=IC/IB. Will more holes in the base make more electrons pass from the emitter to the collector increasing IC and thereby β? Or will IB...

I am an electrical engineer student at SIU and I'm working on an personal project where I am trying to use the following items to supply current between 450-600 mA: 555 timer 2N2222 transistor 4 AA batteries in series for 6V Resistors and capacitors on 555 timer while just resistors on...

Doesn't a transistor switch need a mechanical switch? Otherwise, how does the transistor switch turn on and off? Does the switch have a "mind" of it's own?

Hi, Anyone here can tell me how to control the saturation voltage of a pnp transistor? I was actually doing a project and my design using a pnp transistor to energize a 5V relay.Since I am using 5V supply,I can't afford to drop too much voltage at VCE of the transistor. The design was...

I want to know about the internal capacitance of transistor cbc and cbe

I am trying to find an 500 MHz uhf transistor for a project and I need one which is big enough that i can solder (i.e., not a mm wide) and it has to have the s parameters on the data sheet. If anyone can help me with what i am looking for that would help out a lot! Thanks

Problem Statement: 1. Given that the beta of a transistor is 36, Vcc=5v, Vbb= 3.6V, Rc=440 ohm, Rb=640 ohm, find Ic, and Ib. Also find power dissipated across transistor. Figure: http://yfrog.com/7hdiagram1j Assume silicon diode. [Ie vbe = 0.7] The attempt at a solution I applied voltage...

I got a electrical wiring diagram from my dads friend for a device that he wants me to build for him but the wiring diagram is from Ukraine and i can not seem to be able to find any of the transistors for the device, If anyone can help it would be great. The numbers are KT835, KT827, and a...