Diode Definition and 555 Threads

Homework Statement Homework Equations The Attempt at a Solution Just want to know whether I have the right idea: so to determine the reverse saturation current (IS), I just determine it for each value of VD that was given? So finding IS for 0.6, 0.65, 0.7 etc? The question...

Homework Statement Design a full-wave regulated power supply using a 5:1 center-tapped transformer and a 7.5 V, 1 W Zener diode. The power supply must provide a constant 7.5 V to a load varying from 120 to 450 . The input voltage is 120 V(rms), 60HZ.Homework Equations The Attempt at a Solution...

Hi all. A transformer is driven with a square wave pulse. The transformer has three secondary coils all in series, a diode is placed between two of them which is forward biased during the on time. The coils are used to charge a capacitor and limit current. When the transformer is pulsed...

Homework Statement http://img198.imageshack.us/img198/1421/vintm.jpg Given that k = 2 A) Draw in a qualitative manner the following letters Vin, VP, Vs, Uxy, UR1, UR2, UD B) Calculate the power in R2 C) Calculate the average current through R1 The Attempt at a SolutionI'll start with a...

What is the BJT base current if the base is connected to a zener diode like in the circuit here - http://www.satcure-focus.com/tutor/page5.htm With a voltage divider it's thevenin's equivalent. But with zener, should I consider it as a voltage source?

hello!...I'd like to ask what are the importance of a clipper in a series circuit with diode.What is an input signal because I've read it in the book of boylestad and still i don't understand what is it.what part of the circuit that is being clip?please...it would be helpful for my report.

in diode why there is creation of depletion region? advanced thanks.

Hello :) , Does anyone know some good paper or book from were it's possible to learn physics behind of work of resonant tunneling diode(RTD)? In last semester I had course in ˝microelectronics and nanoelectronics˝ and we studied basic principle on which RTD works, and it was very interesting...

It's pretty straightforward. I built a circuit to energize a coil and connected a diode in parallel to make sure the discharge won't harm the transistor. The diode is in working order, I've tested it with a multimeter and found that it has a high resistor value when forward-biased and it doesn't...

Ok, so let's say I have a simple half-wave rectifier like the one shown in the image below: http://img585.imageshack.us/img585/1904/unledmwc.jpg When it comes to the analysis of the circuit, during the positive cycle of the input voltage, the diode is forward biased and the output voltage...

Homework Statement [PLAIN]http://dl.dropbox.com/u/14490370/bjt.png Homework Equations beta=Ic/Ib By 'ON' I think the lecturer means the saturation region and by 'OFF' he means cut off. The Attempt at a Solution a. My reasoning is Ib= (Vs-Vbase...

Homework Statement The following is a diagram of dc power supply with a Zener diode regulator. For what load current is the power dissipation of the Zener diode maximum? How would you find the approximate value of this maximum power dissipation...

EDIT: I was being stupid and forgot the first diode would turn off after i worked out stuff for diode C, thanks anyway, solution found!Hi I'm having some trouble getting the correct output voltage when i model the diodes using a voltage ofset and resistors. A = 4V, B = 2V, C = 3V Using Voltage...

i have an assignment on PF vs frequency in 3phase diode rectifier the DR want me to draw a graph and stuff but I am not sure how 2 do it or if it does affect the PF. thank you

As we know the potential barrier of silicon diode is 0.7V at "Normal Temperature" But if the Temperature is 120 degree Centigrade then what will happen? 1) the Potential Barrier will increase 2) Decrease 3) Remain Same Please Explain also!

http://img847.imageshack.us/img847/1922/capturevq.jpg I need help starting this. So far I am getting Voh = +10V from the zener diode, and Vol = -10V, the upper and lower saturation limits based on the zener diodes Then for threshold values I am getting an upper threshold Vth = -R1/R2 * Vol =...

Dear Experts, I am looking for some rf vhf diodes. could you recommend a particular model for me? I am quite new to this diode. Are these synonymously called microwave diode / MOSFET / rectifiers / field effect transistor? I am confused what should be the right diode to amplify gsm...

I am trying to understand when clamping diode (at TTL gate input) works and when it does not. The voltage is -2v at cathode and 0v at anode. Fwd bias condition, but the diode does not condut, until the current is reduced. Why so? Initially I thought it was because of the fast rise/fall times...

Hi i wonder if the diode I-V characteristics will be as usual at it is operated at high frequency? Some one told me that it will be not the same. There will be a some kind of hysteresis loop will appear in the curve. Can anyone ensure me about that or give me a useful link about that topics?

hello everyone, i am in disagree with someone over the calculations in the circuits i will discuss with you. circuit #1: here is the diagram:- http://img156.imageshack.us/img156/2734/diodecircuit.jpg do you find it correct? please check it carefully. the circuit will only conduct...

Homework Statement For the circuit shown in Fig. 4.26 both diodes are identical. Find the value of R for which V=80mV Homework Equations I'm not quite sure what equation to use here. If you look at the wiki page on diodes http://en.wikipedia.org/wiki/Diode it might be Shockleys...

Homework Statement Design a rectifier with a zener diode that satisfies the following: Primary voltage = 120V @ 60Hz VDC = 12V IR2 = 100 mA (R2 being the load) Vr(R2) <= .3V Homework Equations C=IDC/(2fVr) IDC=IR3 + IR1 The Attempt at a Solution I tried calculating the...

I am a little unsure about why the ideal diode can't have positive voltage drop... Looking back at my notes, it just simply says that "It's not a feasible solution" and that only when voltage drop is zero or negative can there be a solution.

hi everyone, please see fig 42.25 a and b on this google doc:--- https://docs.google.com/viewer?a=v&pid=explorer&chrome=true&srcid=0B_XrsbDdR9NEMDNhNzVhZTktNzZhMy00ZGI0LWEyZGYtM2RmMTA3MDQxMTlm&hl=en&authkey=CKP-7OsD i can understand the fig 42.25a and why the current flows. but i have...

Homework Statement The absolute max voltage rating for the base-emitter voltage is the lowest of all values. This low value means the B-E junction must be protected from a high reverse voltage. A diode is used for an npn transistor. Explain its function and conditions under which...

Hello Forum, trivial questions: physics phenomena are usually explained via simple models. In DC electronics the water analogy is often adopted but breaks down when we move to AC. When a simple diode is forward biased DC current is able to flow in the circuit powered by a constant voltage...

Homework Statement I have been doing an experiment, and I needed to calculate the value of η for a diode. The value should be between 0.5 and 1.0... The value for alpha obtained is 20. Homework Equations αV=ηeV/kT Where k is Boltzmann’s constant, eV is the electron volt, T is...

So I'm trying to understand the relationship between current & voltage as well as the basic electricity laws and Diode operation. Attached are 2 circuit diagrams for reference. Assume that Diodes can withstand against whatever voltage/current the circuit generates. Can Anyone explain me what...

Homework Statement What would happen if the load resistor was short-circuited. What would happen if the load resister was removed? -see attached diagram- Homework Equations P=Iin^2*R Pz=IzVz =(Iin-Iout)Vz=[((Vin-Vz)/R)-Iout]Vz The Attempt at a Solution I'm not sure about...

Homework Statement ok i was doing an experiment on p-n diodes i was asked to plot graph of voltage across resistor VS voltage of diode with a DC source varying from 0 to 30V resistor 1k ohm The Attempt at a Solution i understand the forward bias where the graph shows that the voltage across...

fastest modulation: laser diode vs LED... Hello Forum, in the telecomm industry, the most common and economical form of modulation is direct modulation, acting on the current operating LEDs or diode lasers. Using an external intensity modulator (OOK), like a super fast chopper, the...

I have found a circuit that uses a BAS16 small signal diode to level shift a 5V (or 3.3V) TTL signal down to a 1.8V TTL signal. The cathode of the diode is on the high voltage side and the anode is on the low voltage side, so it looks like it is backwards compared to the direction of current...

Hi What could be the band diagram of pn-junction diode at very low temperature where dopant ionzation is completely frozen out? Would it still be like the band diagram at room temperature?

A series LC circuit at resonance has a higher total voltage than the applied voltage due to voltage magnification. If a diode were inserted between L and C it would prevent the back and forth oscillation of energy, But would it prevent voltage magnification if the circuit were driven at...

Hi, I am new to EE. On this page - http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/diodgate.html#c1" - the very first circuit shows a diode-resistor AND gate. How does that work? I understand the OR gate shown right below it, but... the two inputs on this AND gate are connected to reversed...

Note: This is a past paper, I'm simply revising for an exam. But I thought that this was the best forum to stick it in. Homework Statement http://exampapers.cf.ac.uk/papers/engin/en1051/en1051a09.pdf Section A, Q1 c http://img684.imageshack.us/img684/9695/questionm.jpg Homework Equations...

Hey, I'm trying to find a suitable diode to protect against some back EMF in my circuit, but I don't know much about them and so I'm having a really hard time finding one. If someone could look at what i need and then possibly send me a link i'd be so grateful. Requirements: back EMF = 137mV...

The attached circuit is not my design but I need to understand it completely. This is a circuit that supplies power to a sensor. When S1 is closed the power is removed from RL. What is the purpose of D1? In General, what happens if R1 were to short? I know the base would be subjected to the...

I'm trying to figure out what the IV characteristic curves are of some simple diode circuits. A) Diode and resistor in series. B) Diode and resistor in parallel C) Diode and resistor in parallel, and this combo in series with another diode reversed wrt. first diode. Its been a while...

Hi. A circuit has two zener diodes connected in series. The voltage reaches the diode's reverse breakdown voltage (VzDiode1 and VZDiode2 are the same = 10V). The Vi of the all circuit is 8 V. / / 8v -----|<|----|<|---- Ground / / +...

I am trying to build a simple laser diode driver problem is, I built the circuit without taking the diode into consideration, and am getting the right current outputs (45mA for 0 bit and 90mA for a 1 bit) but every time I insert an LED just to kind of simulate the laser diode, I get some...

Hi everyone, I've been looking at the data sheet for a pulsed laser diode driver that I've been using, and I've managed to convince myself that there's a mistake. I was hoping that if I post my explanation of how the circuit shown in the data sheet works, that you guys can either confirm that...

Homework Statement [PLAIN]http://img27.imageshack.us/img27/4475/q12r.png Homework Equations KCL/KVL Mesh current, node voltage ohm's law The Attempt at a Solution for b) I understand how diodes work, and i'v deduced that diode 2 is definitely not conducting as the voltage on it's anode is...

two ideal diodes are are connected in parallel. this combination is connected across an ac source. the diodes r such that if one of them is forward biased other is reverse biased. now in the positive half cycle let us take that 1st diode if forward biased and the second reverse biased. if the...

diode and retifier application?? i have a question are diode and rectifiers used in electrical transformers?

Homework Statement The dc reistance of a silicon diode for a current of 10 mA is closest to: Homework Equations Really not sure. The Attempt at a Solution Not sure where to start, this goes with a lab I just completed but not sure if this problem directly correlates to it.

I am going to be pulsing a laser diode at around 2 Watt (room temperature) with a frequency of around 1-10 MHz. Right now I'm planning on using 26 AWG wire. Anyone have any thoughts on whether this is okay? Is the gauge okay? Since it's pulsed I assume I don't have to worry as much about heat...

Homework Statement Determine the diode current with Is=50nA and an applied forward bias of 0.6V Homework Equations Id = Is ( e ^ (kVd/Tk) - 1) The Attempt at a Solution So my teacher is horrible and this is what I have been able to collect on my own. Is = 50 and Vd = 0.6v I'm...

Homework Statement Find values of I and V for the circuits of figure; assuming that the diodes are ideal. http://yfrog.com/081034op Picture: http://img8.imageshack.us/img8/3026/1034o.png Homework Equations I can use KVL/KCL. And have a rough knowledge of finding wheather a diode is on or...

Hello, I am designing a motor controller, and I was curious about the MOSFETs I'm using that have an internal body diode zener for Vds protection that is common in a lot of datasheets. I am switching the coils of the inductor with these MOSFETs, and I would like to know if its unwise to...