Diode Definition and 571 Threads

Why doesn't the voltage vary beyond breakdown voltage in zener diode?

Lately I've been rediscovering my old interest in electronics and in my own time I've been looking through some tutorials on various things I decided to go ahead and build one, an H bridge circuit for a 5 volt DC motor. My question is I'm not clear on which diode I should use as flyback diodes...

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...

Determine the reverse saturation current for the diode below, given that VS = 5V, R = 360Ω produces a diode current of 10mA. Use h = 1.3 and VT = kT/q = 25mV. I believe this is the formula needed. Id = Is(e^(VD/(h*25mV))-1) The problem I had was I've done several questions similar to this but...

Hello, When the diode is in forward bias phase and suddenly we apply a reverse bias voltage, the diode takes time to be fully blocked because of the excess of minority charges that are stored in P and N region. Thus a reverse current appears in the diode for a short time before it is blocked...

here is the manual http://www.axis.com/en/files/manuals/um_p1355_49956_en_1303.pdf see page 61 Notes: i have seen this thread https://www.physicsforums.com/threads/axis-camera-with-i-o-and-relay-to-turn-on-lights.538043/ but this camera is a bit different i think as it has digital inputs and...

Homework Statement Can someone explain me what are high field domain or can give me a source from where I can understand it.It will be very helpful. Homework EquationsThe Attempt at a Solution

Homework Statement What is the current flow when a diode is connected in series with a resistor and battery.The cathode of the diode indicated as A is connected to the positive battery terminal.The Anode of the diode indicated as B is connected to the one leg of the resistor and the other is...

Hello, Capacitor When a capacitor is connected to a voltage source, electrons will move from one plate and accumulate in the other in accordance to Q=CV. Due to the imbalance of charges (positive and negative ions) between the plates, an electric field exists that flow in the direction of the...

Homework Statement Homework Equations Whenever assuming a diode is "on", replace that diode with a 0.7 voltage source. Whenever assuming a diode is "off", replace that diode with an open circuit. The Attempt at a Solution The problem is pretty straightforward but the format of the circuit...

I'm trying to understand how a diode works and for this I've used(among other resources) the book written by Albert Malvino, Electronic Principles. Everywhere I read about this topic, it says that when the N-type and P-type semiconductors are joined together, the free electrons from the N-type...

So I was reading about magnetic semiconductors and I got confused so can you please clarify I will ask a question that is made up of two parts. Magnetic semiconductors are ... a) devices that alter or switch on/off electric current flow depending on the magnetic field strength etc applied OR b)...

Hello all Textbooks teaches us that in the formation of Pn junction in between P and N type semiconductor a region is formed where free electrons of N diffused in P side and exhaust by the holes of P near the junction. Such a region becomes devoit of free charge careers and their are only ions...

Homework Statement Homework Equations Model diode in reverse direction as an open, model diode in forward direction as a short. The Attempt at a Solution In part e of the question, does the circuit stay in state 1 after it gets into state one or does it change states?

Homework Statement Find the currents and voltages indicated for the circuits given: Homework EquationsThe Attempt at a Solution I needed some practice, and I want to ensure I understand for the harder problems later. (a) The diode is going to behave like a short circuit, so the current...

Homework Statement Design the circuit in the following figure so that ##V_o = 3V## when ##I_L = 0## and ##V_o## changes by ##20mV## per ##1mA## of load current. (a) Use the small-signal model of the diode to find the value of ##R##. (b) Specify the value of ##I_S## (saturation current) of...

Homework Statement :[/B] I don't know how to do connections.I just know how to do it in specific type of zener diode because i have learn this.I don't understand these connections.Within 30 minutes i have to leave for my exams please help.Homework Equations [/B]The Attempt at a Solution -[/B]...

Homework Statement This diode zener has breakdown voltage equal to Vz=8.2V for currents: 75mA<=iz<=1A.If RL=9 Ω,how much must Rs be,so that VL=Vz=8.2V,while Vb changes at about _+10% in relation with the nomimal operating current,displayed in the data sheet which is 12V? The Attempt at a...

As far as I know, Compact Fluorescent Lamp (CFL) is an inductive load. I understand that inductive load doesn't allow an immediate change in current. When the circuit was initially open (through open switch) then became close, the inductive load was energized. So opening again the circuit after...

hi, On a diode datsheet, is the value quoted as the forward voltage the same as the cut-in voltage?

I understand the process of rectification but just only in theory. But I still have questions that I guess will be answered if I can experience or has experience about it (but sadly I don't have). Please kindly answer these questions: 1. Does the waveform of Vout can be considered as DC (...

When pn and zener diode is connected according to the circuit diagram(manual not diode box,ie, by connecting wires) it shows great fluctuations and readings can't be able to take. What may be the reason for this and how can i rectify?

Hi, For a PN junction diode, am I correct in thinking that the barrier potential (due to depletion region and hole-electron recombination etc.) is the same as the 'forward voltage' quoted on datasheets? Also, when a forward bias condition is created and the applied voltage is greater than the...

Homework Statement We have the circuit in the figure.I have to find the output graphically if the input is Vi=15sinwt. Homework Equations This type of exercise doesn't have any equations The Attempt at a Solution Heres the circuit http://i.imgur.com/ivixWzH.jpg For Vi<= -10 the diode is ON...

what happens to the minor charge carriers in p-n junction diode when forward biased?

What is meant by diode polarity. If we do connect anode to positive and cathode to negative then its means it works on Forward Bias mode. I think positive means higher potential than negative, in other words, if positive terminal which is Anode is to be at 5 volts and negative terminal which is...

I am not getting why there can't be (or very negligible )current in reverse diode.According to this image positive terminal of battery would suck electrons from n-type and pass them to negative terminal of battery.And Negative terminal would provide electrons to p type and from there we can see...

The question is to solve the current through a resistor after a pn junction. (photo attached) As far as I'm aware the voltage source in the pn junction is (in this orientation) of opposite polarity to that of the 0.8V voltage source. From my understanding the answer goes like: V=IR I=V/R...

Hello, When a Voltage is applied to a diode, how the electric field is established inside the diode? Is it the same as a resistor which surface charges density establish electric field inside it? Thanks

< Mentor Note -- Thread moved to Homework Help from EE forum > hi guys I am studying on diode circuit but i cannot really analyse a circuit with a diode. I understand that the question is asking minimum Vout so the current source input should be -2.5mA but i cannot go beyond that. Can anyone...

Is it advisable to use an LED instead of a PN-junction diode and what is the resistance of each (or do they vary)? The only reason I'm asking is LEDs are easier and cheaper to get. P.S. What I need it for, only needs a PN-junction diode.

Homework Statement http://prntscr.com/51us65 the diode is ideal.What i need to find is the Vout-t Homework EquationsThe Attempt at a Solution check my solution in pdf and guide me if you can... ***In my approach,in the circuit i forgot to draw the line.It is supposed to be a short circuit,not...

Just joined and looking for information on which diode to use to protect a 12V battery charger circuitry connected to a battery. it is charging. Should the mains supply fail ie battery charger has no forward current, the battery may apply voltage and current to the circuitry damaging the LM338...

Homework Statement 1a) Use an ideal diode model and find V in both cases. Show your work. (I would assume an ideal diode model means with a "perfect" u-i characteristics?) A diode circuit is as shown: 1b) If V1 = 2.8sin(t), sketch to periods of V1 and V0 in the same graph. Use an idea...

Homework Statement I need to find the current, but not sure how to rearrange the equation because of the I in the exp. Homework Equations The Attempt at a Solution Thanks, just need to be pointed in the right direction. Seems like I will either be in ln or exp.

Hey guys, I'm trying to wrap my head around this electronic schematics of a PLC, because I've started ladder-programming it. Can anyone explain to me why are there TWO diodes before the transistor? I get that one diode shows an "active" or "inactive" state when it's turned on or not. But why...

Homework Statement Homework Equations r_d= V_T/I_D, V_T=25mV The Attempt at a Solution i alreayd find the operation of diodes, D1 off and D2 on (2nd circuit). the current through this diode i also calculate as 34mA, also r_d=0.7353 ohm. I am having trouble using incremental model, in my book...

Homework Statement (circuit attached) If the circuit shown, D2 has 10 times the junction area of D1. What value of V results? To obtain V=50mV, what current I2 is needed? Homework Equations I = I_S * (e^(V/V_T) - 1), V_T=25mV I(D2)/I(D1) = e^((VD2-VD1)/V_T) The Attempt at a Solution If D2 has...

The Q-point for the Zener diode in the figure given is ?

The Diode in the circuit shown below has the non linear terminal characteristics as shown in the figure.Let the voltage be "coswt" V . Question 3.1.33 and my attempt is shown in the figure.

Homework Statement We have Vz=6.8 V and Iz=5 mA,rz=20 Ohm,Izk=0.2 mA, R=200 Ohm and the source V= 9 volt a)Find the output voltage when we have the input voltage with the nominal value of 9 Volt. b)Find for the nominal value of the voltage,which is the maximum load current for which the...

I understand there is some "leakage" current in a reversed biased diode but I don't understand why there is significantly less current in a reversed biased diode. I've seen the band diagrams and if all the electrons were only on the n-side of the diode, I would understand why the electrons can't...

Please Help. I am not getting the concept of ripple factor in half wave rectification with the help of diode.The derivation done by our lecturer is not clear.Someone please explain the concept and its derivation. Also it seems from the derivation given by our lecturer that there are two types...

Hi all. I started a thread a while back about RF mixer design. I didn't know what to do or what design to choose. You guys laid some options for me and after some research and time I have finally decided that I will go for a double balanced, ring diode topology. Here is a schematic from google...

What is the order of the reverse saturation current before breakdown in a zener diode ?

In the given circuit we have to find the output voltage , the voltage drop across resistance RL (RL = 10KΩ) and the current through the zener diode having zener voltage VZ = 50V By this question I want to be clear about the way to solve circuits with zener diode...please explain the...

So I am currently using TB6612FNG motor driver (see https://www.sparkfun.com/products/9457) to drive two dc motors. Now I wanted to connect a flyback diode (1n4001) to prevent any potential damage to the motor driver that may occur from the back voltage of the dc motors after I terminate the...

As I have studied that when the reverse voltage across zener diode is less thsan the zener voltage it is replaced by open circuit..now in the given fig. (input voltage 100V & zener voltage=50V) we are not knowing the voltage across the reverse voltage across the diode..but in its solution it is...

Homework Statement DC analysis is required for the question in attachment. Vz=6V B=100 Vbe=0.7V Homework Equations The Attempt at a Solution I tried to find the result using the currents that were defined by the transistor. I found a result that was nonsense, the base current...

A new spintronic LED was invented by Utah physicists. http://unews.utah.edu/news_releases/utah-physicists-invent-spintronic-led/ I thought that electron and hole suppose to recombine if electron is in exited state which means electron-hole pair is not in thermodynamic equilibrium with...