Tagged Questions

Diodes are semiconductor components made from a P-type and N-type silicon material, that allows current to only flow in one direction.

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2answers
46 views

Zener Diode Minimum Input Voltage

My question is with regard to establishing regulation using values taken off the characteristic curve. I have \$I_{kn}\$ = 1.8mA and \$V_z\$ = -8.2V. How can I determine the minimum input voltage for ...
1
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0answers
24 views

555 timing formula when the diode forward voltage drop is not neglected

(Image Sources) In this modified astable multivibrator circuit the forward voltage drop of the diode D1 is always ignored, and the timing formulas are given as $$ t_1 = \ln(2)R_1C_1, \quad t_2 = ...
2
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1answer
57 views

Using diodes to mix 2 audio signals into one set of speakers

I have the audio output of 2 computers connected to only one set of speakers. Each computer uses one of these external USB sound cards: And I use this splitter cable to wire the signals together: ...
6
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1answer
494 views

Do serially connected diodes share equal reverse current?

If I place three cheap 200 V rated diodes across a 500 V supply instead of one expensive diode, is the system guarantied to work correctly? My worry is the situation at which two of the diodes share ...
0
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1answer
41 views

Correct use of diodes in car stereo

Could I check my use of diodes in the following circuit? I'm wiring a new car stereo head unit into my motorhome (RV). I'm going to use most of the standard radio harness connections. However I ...
2
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3answers
58 views

Which diode to use on my RC switch debounce circuit?

I am choosing parts to build an analog RC switch debounce circuit. I plan to implement the circuit described here: http://www.ganssle.com/debouncing-pt2.htm (see "An RC Debouncer"). These are the ...
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1answer
29 views

Analyzing input/output characteristics of a diode circuit

In "Fundamentals of Microelectronics" textbook. The question number 27 of chapter 3 is: The part b of the question is: And the solution of b from the solution manual of this textbook is: Can ...
0
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1answer
47 views

How will the diode act after its junction is penetrated?

Above is a circuit diagram with 2 sources V1 and V2, a switch SW, a diode D1 and a resistor R1. The points X,Y,A,B,C,D,E,F are terminals of the components indicated with red dots. If the switch is ...
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3answers
81 views

Diodes block voltage?

I understand the basics of a diode, a diode allows current to flow in only one direction, but how? By blocking any opposing voltages source so that no current can flow in opposition? And of course, a ...
-1
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2answers
105 views

Will the current flow through the diode?

This question originates from a difficulty to understand fly-back diode current in DC motors. In the above figure which logic is ok: 1) 9V-2V = 7V, so diode is reverse biased and current will not ...
3
votes
1answer
145 views

Analyzing circuits with diodes

In "Fundamentals of Microelectronics" textbook. The question number 25 of chapter 3 is: This is part c of the question: And this is the solution of part c from the solution manual: For the ...
0
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0answers
58 views

Input/output characteristics for this diode circuit

Given this circuit: Assume VB = 2V, constant-voltage drop model, and VDo = 0.7V. How to plot input/output characteristics? Here is my try: When the diode is on, we replace the diode with a ...
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2answers
58 views

Getting square impulses from square wave input

I can't get this problem right... This problem was given by my professor as a possible exam question. I took a considerable amount of time thinking in it, but I'm yet unable to solve it. The problem ...
3
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1answer
60 views

Metal semiconductor contacts

I’m headed back to the CNF (http://www.cnf.cornell.edu/) shortly. It’s a user clean room facility for semiconductor processing. My goal is to make some very simple samples, for use in student teaching ...
1
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1answer
103 views

Specification Requirements for a TVS Diode

I want to add a transient-voltage-suppression (TVS) diode to my design, but am getting confused about the specifics around Maximum Clamping Voltage, Maximum Peak Pulse Current and Minimum Breakdown ...
1
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2answers
145 views

Voltage not dropping in circuit

This schematic shows the circuit that I'm trying to build. At the moment I'm not using V2, as I'm having a problem with V1. From my understanding the diode should drop the voltage by about 0.7V, and ...
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0answers
41 views

Max peak to peak swing across ES without any clipping distortion?

This is an exam problem in which my instructor gave the answers but no work. Any one has an idea of how to solve it;FOM(figure of merit)= 25/125, RL=15 ohms, Rx=250 ohms, r1,r2,vee,vcc, are not given. ...
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3answers
55 views

Analyzing a circuit with diodes

In this circuit: Assuming ideal diodes We have 8 combinations of assumptions. I have proved that 5 of them are wrong. The three remaining assumptions are: All diodes are on. D1 is on, D2 is off, ...
2
votes
4answers
174 views

How to calculate Vx in this circuit?

In this circuit: Assuming ideal diodes We are required to calculate VD1, VD2, ID1, and ID2. If I assume that D1 is off and D2 is on which is a wrong assumption (as I think). How I prove that it ...
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6answers
143 views

How to calculate Vo in this circuit?

In this circuit: The diode is an ideal diode The diode is on since V(anode) > V(cathode) and then we replace it by a short circuit. Now, how to calculate Vo when two sources are existed? I = (10 ...
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3answers
314 views

How do I analyze this circuit with diodes?

If diodes in this circuit are ideal diodes: I'm making assumptions to solve this circuit for I and Vo but I have some questions: 1. What is the voltage at the cathode of the upper diode if the ...
0
votes
1answer
48 views

How do you determine graded versus abrupt diode junction types?

The problem When a diode is reverse biased with 8V, it has a junction capacitance of 15pF. When the reverse biased is increased to 12V, the capacitance drops to 13.05pF. Find whether it's abrupt or ...
3
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1answer
47 views

Sedra and Smith Example 3.2

Problem: Assuming that diodes are ideal, find I and V. This is a worked example in the textbook and it says that if you assume both diodes to be conducting then V=0 and VB=0 (nodal voltage at B). ...
5
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1answer
278 views

Zener diode circuit

When I tried to find current flowing through 1.2k ohm resistor, I am finding 8.33 mA but there comes the problem: I am finding the current through the 1k ohm resistor is 6 mA. What am I doing wrong? ...
3
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1answer
163 views

Can a photodiode emit light?

I read that an LED (primarily emits light) can also be used as a photodiode (primarily detects light). Is this true in reverse? I mean, can a photodiode also emit light?
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3answers
97 views

Compensating input impedance

I'm trying to measure the reverse leakage current of some diodes with the method proposed HERE - the diode is connected in reverse bias to 5V through 1 megaohm and voltage is measured across the ...
1
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1answer
67 views

Why does it take several seconds of time for the photodiodes to come out of saturation?

I am currently studying about photodiodes and came across this fact that photodiodes take quite a bit of time to come out of the saturation. What really happens during this time (after it is saturated ...
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2answers
80 views

Design help for my 1A variable power supply

In a 1A Variable Power Supply circuit given below is it possible to use a 2A transformer and 1A bridge diodes.
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2answers
62 views

Problem with a circuit of an controlled variable voltage source

I have this circuit, it should regulate the output voltage between 15V and 0V. But the output I get when I simulate it is between 2V and 3V, and when I implemented, I burned zener diode 1N4734A. ...
0
votes
1answer
51 views

Selecting diodes for HV full bridge rectifier

I'm using a current-fed Royer self resonant circuit to generate 1kV DC output voltage. The transformer is producing a sine wave of 100kHz/2kVpp (Cap-Royer = 100nF). At the output of the transformer I ...
0
votes
1answer
73 views

Zener diodes comparison 12V vs 6V2

12V zener diode has the same series as 6V2. It also has same wattage of 500 watt but VZ of 12V. Will it handle the same maximum current IZT as the 6V2? Any proof?
5
votes
2answers
350 views

Switching between battery and USB using diode OR logic

I have a Raspberry Pi that is powered by a USB cable from a Samsung charger. Now since my college has frequent power cuts, I designed a basic switch to automatically switch between a portable mobile ...
2
votes
4answers
113 views

Anti-wind up scheme in the implementation of PID controller

I want to implement designed PID controller. But I am facing the problem of how to limit the saturation limit in both positive and negative direction? I tried using zener diode, but I would like to ...
1
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1answer
49 views

Flyback converter current flow?

If you look at the flyback converter circuit above, the current only flows in one of the coils at any instant of time. What stops the magnetic field generated by the coil in series with the MOSFET ...
0
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2answers
49 views

Meaning of zero load and full load in circuits

This might be straightforward but it has been tough to grasp for me. When a question says to calcualate the power dissipated by the Zener diode under zero load and full load. What exactly does the ...
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3answers
82 views

voltage change inn diodes [closed]

voltage relation diodes of rectification process related to electronics
0
votes
1answer
47 views

PSpice OrCAD Adding Diode and Unknown Source

On the PSPice OrCAD, how do you add a diode with a 0.7V forward bias and a unknown voltage source?
0
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2answers
59 views

Why is the Vbe threshold of a Si NPN transistor 0.7V and not -0.7V?

In case of an n-p-n transistor, the Vbe is more like voltage across a p-n diode. Now, since the direction of electric field in the depletion-region is from n to p, how come the voltage across the p-n ...
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votes
1answer
45 views

Diode equation.Needs understanding [duplicate]

Kindly explain this equation for me.I do not understand what it means and from where this equation comes out?it's a diode equation $$ r^{\prime}_d = \dfrac{26\mathrm{mV}}{I_D} + r_B $$
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votes
2answers
150 views

What are the use of these diodes?

I have a circuit diagram which is for a circuit used for testing batteries under a load, only one of the batteries can be tested at a time and I was just wondering what the point of the diodes in the ...
0
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2answers
69 views

For the circuit shown, use exponential model of diode to find value of R for which v=80mv

I know how to do this if the diodes were ideal, however here, they aren't. I've tried. Please help out. I've gone this far: log (iL/i1) = (v/vT) i2/i1 = e^3.345 (assuming vT = 25.4mv) i2/i1 = 23.31 ...
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1answer
87 views

Explain the equation [closed]

Explain the following equation... $$ r^{\prime}_d = \dfrac{26\mathrm{mV}}{I_D} + r_B $$ Explain from where and how this equation comes out . Also elaborate the terms used in above mentioned ...
0
votes
3answers
124 views

Precision half wave rectifier

How does a precision half wave rectifier work? The one with a single diode. When the input goes positive, the output of the op-amp is a large positive signal which turns on the diode and completes ...
0
votes
0answers
24 views

Find the Output curve for the given Input Curve

For the circuit given below find the output wave form for the given input wave. The following are the answer choices for the curve of Vout. The answer choice selected in my book is (3) Please ...
0
votes
1answer
49 views

Cutoff and Conducting diodes

Why is D1 considered cutoff and D2 considered conducting ? Note : I am working with constant voltage model where the diode voltage is 0.7v and I need to figure out I and V. Please explain why D1 is ...
0
votes
1answer
83 views

What is the purpose of the following configuration of diodes on an RF line?

I've been told that these are disconnect diodes. However, I am unsure as to what purpose they serve. They are used on the line that sends a signal to a piezoelectric, the return signal from the ...
1
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0answers
35 views

Graph of the output Vo for a given Vi in a diode circuit explanation [duplicate]

We have the following diode circuit: We have found when the diode is on and off. I perfectly understand this. Now the teacher gave an extra question that I don't understand. What is the output ...
0
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1answer
71 views

Diodes circuit question please help?

We have the exercise in the figure.I understand the answer.Now my question is: Whatis the output going to be if we put an input of V=10sinwt? Can you draw it for me? Not totally accurate,just so I ...
1
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3answers
200 views

Where to put freewheeling diode in relay circuit?

I am building a circuit to lock/unlock a door using a standard electromagnetic door lock (http://www.amazon.com/Seco-Larm-E-941SA-600-Enforcer-Electromagnetic-Holding/dp/B00196YB5Y) and controlling it ...
2
votes
5answers
429 views

Diode circuit with parallel voltage source

What will be voltage V if all diodes are considered ideal simulate this circuit – Schematic created using CircuitLab