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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Diodes in parallel circuit analysis

Could some please help me understand why D2 is on and not D1 on a) and why is D1 is on and not D2 for b). This is for ideal diodes
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40 views

Building a micro generator, I need to account for the pulsing DC after my 3 phase diode bridge

I wound my own motor, and tested it to be about 300 RPM per volt, and if my noob math is right, it should be able to handle about 1600 watts with a ~40 volt supply without burning my nice but thinly ...
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2answers
108 views

Why does my LED blink when too much voltage is applied?

I bought a set of simple light-emmiting diodes. Connecting one to Arduino's full 5V output (without a resistor) causes the diode to blink. However changing the duty cycle to a value below 80% causes ...
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1answer
64 views

Diodes question is this correct?

We have the diode circuit in the figure. The diodes are real and Vd=0.7 Volt I have to find the currents in the diodes and in the resistances R1 and R2 So I apply KVL in loop 1 and I have -20+ ...
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1answer
38 views

What Diode have I here?

I am trying to figure what is with my broken power adapter (230V AC -> 12V + 5V DC at both 2A). After checking the fuse, now I extracted two heavily cooled diodes, which could be the cause. But I ...
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2answers
57 views

Diode: reverse and forward bias current and voltage

The question asks : "Assume that diodes have voltage of 0.7 V and resistance 4Ω. Find the current through the forward and reverse bias of diodes. Draw the characteristic of diode through the given ...
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1answer
39 views

Wiring laser diodes in parallel [closed]

I'm a beginner, so please have mercy. I have a lasercap and notice that on the negative side of each laser diode, the negative wire TO the diode and the negative wire FROM that diode (to the negative ...
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2answers
52 views

How can I make a log amplifier's logarithmic region span across the range of 0-5V input instead just working close to 0V?

I need to implement a log amplifier. Currently I'm doing it using a diode in the negative feedback loop but it only really gives me the log response close to the zero input, with the amps output ...
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1answer
49 views

Is there a simple circuit which would behave similarly to a diode, but with a higher cut-in voltage?

I was wondering if there exist any relatively simple circuit which would have an I-V characteristic similar to that of a diode (i.e. exponential but small before the cut-in voltage) but with a higher ...
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1answer
79 views

Why diodes are made up with semiconductor?

I am little bit confuse about 'Why diodes are made of semiconductors'. I know the properties of semiconductor and also know the process of doping but still confuse to get the answer. Why the making of ...
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2answers
47 views

Use of MOSFETs body diode

I have an N-MOSFET array IC and I don't need to use all of them, but I do need to use a diode. Is it OK to use the body diode of one of the MOSFETs as a regular diode to decrease component count and ...
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2answers
64 views

How to design capacitance value for a given full wave rectifier [duplicate]

I have been searching for design equations for 5v regulated power supply but unable to figure it out. Please check the below circuit diagram Could anyone explain me why 470uf ? why not 2uf? how can ...
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1answer
57 views

DC motor working on Arduino but not Attiny with batteries [duplicate]

I have a simple working circuit to control a DC motor with an Arduino as indicated in the Arduino examples. For instance, ...
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0answers
26 views

ideal/non ideal diode design using Multisim

I am design the following circuit using Multisim, but I came across a problem. I used 1N4004 for ideal model, but I have no idea what would be the model for non-ideal ( ideal + 0.7 V). or I just ...
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2answers
75 views

BJT Switch with a Diode from Base to Emitter

In this circuit, the diode is supposed to force a higher input voltage to turn the LED on, however when I created it on a breadboard I measured about the same input voltage (without the diode) to turn ...
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1answer
51 views

Trying to understand flyback diodes and general diode orientation

Let's start with this: I know the top image is of a flyback diode. I also get that its purpose is to protect the power supply from a voltage spike when the electromagnet releases. So I've gotten ...
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3answers
82 views

Calculating voltage in diode circiut

Could you explain to me why U_out is -4,4V and only 3rd diode is open in the following example? Given that R is 10kOhm. My physics resistant brain tell me that voltage at each anode is is 10,15 and ...
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4answers
65 views

LED Voltage Drop Confusion

Please take a moment to checkout the simple circuit below: simulate this circuit – Schematic created using CircuitLab As you can see, this is a simple circuit consisting of three LEDs in ...
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1answer
91 views

Reduce power supply voltage

I'm trying to build the power supply described here. R1: 1K8 1/4W Resistor C1,C2: 4700µF 25V Electrolytic Capacitors D1: Diode bridge 100 to 400V, 1.5 to 4A D2: LED Any type ...
3
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2answers
98 views

Precision high speed peak detector

As a follow-up to my previous question, where I seek to determine the amplitude of a 2 MHz sine wave, I've settled for an op amp based solution. To recall, my input has a maximum 240 mV amplitude -- ...
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1answer
62 views

How does Multisim calculate voltages?

If I rectify 10Vac (rms) by diodes without a voltage drop to a full wave pulsating dc, the peak voltage would be Vrms x square root of 2 = 14.142135V The dc (average) voltage would be 2V peak/pi = ...
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5answers
72 views

Diode homework: How is Vo calculated?

For this circuit we're asked to calculate Vo using the 0.7V diode model. simulate this circuit – Schematic created using CircuitLab I understand that when the potential is higher at the ...
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1answer
167 views

Does reverse biasing hold any meaning in case if both terminals are n type semiconductors?

When we talk about an n-p-n transistor in common emitter configuration, we often say that emitter-collector circuit (the one towards right) is reverse biased. In what sense it is reverse biased? Here, ...
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4answers
158 views

Why can't I get a output lower than 0V in this diode and capacitor circuit?

In the image above green is my input (node left side capacitor) and blue is my output (node right side of the capacitor). I would expect that the blue signal would follow the input, but it does not ...
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4answers
362 views

Forward biasing a diode past built-in voltage

Why can't we forward biase a diode past its built-in voltage/potential? What's the problem in doing so?
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1answer
73 views

Does back to back connection of PN diode works exactly as transistor? [duplicate]

I have a doubt related to back to back connection of PN diode.... Does back to back connection of PN diode works exactly as transistor? It looks like a small doubt... But I want detailed information ...
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2answers
1k views

Half-wave diode rectifier - is textbook wrong?

I've noticed that in all resources on diodes and rectifiers, they show the output voltage as the positive half-wave of the input signal. However, that seems wrong. I understand that there's a voltage ...
2
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2answers
86 views

I-V characteristic of Diodes

I need to develop mathematical equations (models) to represent the I-V characteristics of a Zener Diode, Signal Diode and Rectifier Diode. I have done research and I've only been able to come up with ...
2
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1answer
129 views

Using a capacitor to keep circuit powered for 1s after battery disconnected?

I am planning on using a 3.3V GPS module which draws 22mA. The module has a requirement that a shutdown sequence be initiated 1s before power is removed from the IC. If power is removed without ...
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3answers
329 views

Transistor Protection without Diode

I wanted to know if there is a way to protect the circuit from a relay. Usually you add a backwards diode for protection, because when you turn off the relay, the magnetic field in the coil collapses ...
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1answer
64 views

What to expect when i place a diode in magnetic field

I am designing a PCB that senses basic NTC values and converts it into digital format. The problem is the entire PCB is above a magnet(about 70mT at the board) that is moving. Hence i want to know ...
2
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1answer
76 views

Help with Wiring LED Parking Light/Turn Signal using manufactured Bolt LED

In my search to find the best way to complete this pet project on my truck, I found this site. I've searched but as I am using a manufactured flush mounted bolt LED lighting unit I still have some ...
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1answer
40 views

Deciphering the identifier for a diode

I need to replace a burned-out diode. It is marked P6KE16A 240K. What do these numbers mean? Is there any information encoded? (e.g. 16A, 240K-Ohm) Is this information sufficient for sourcing a ...
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1answer
44 views

ideal diode resitance

the questions goes like this: model ideal diode (0.75V battery and 100 Ohms resistance) and then calculate the average V0. I know how to add the 0.75V but how can I add the resistance to the diode? ...
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1answer
160 views

Plotting Vout vs. Vin Curves for an Ideal Diode / Resistor Circuit

I am trying to plot the Vout vs. Vin for the following circuit, assuming both D1 and D2 are ideal, the forward voltages are V(D1,on) = 0 and V(D2,on) = 0.7V, R1 = R3 = 1 kOhm, R2 = 4K, and E = 3.3V. ...
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1answer
84 views

Alternative to diode [duplicate]

I have this electronics that uses 3V rechargeable coin cell battery (ML2032) to power the RTC when the system is off. When the system is powered on it'll trickle charge the battery instead. I'm ...
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1answer
47 views

Current Activated Diode Switch

Ok so here's my situation. I have a custom board with a micro controller that has a 6 pin connector. If I plug in a device to the connector that requires power it should provide somewhere on the ...
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3answers
159 views

Electronics I problem

Suppose that Vin= -∞, that forces D1 to open(OFF) and D2 to close (ON). Given E is 2 , then Vout=-2. Then I applied KVL to find the equation for Vd1 ( Off). Now I know that I have to find the ...
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1answer
69 views

dynamic resistance of PN junction diode

I am lost here, I was wondering what voltages do I have to include in the equation that is asked for both v1 and v2? and how do I do that?
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1answer
89 views

Diode reverse recovery charge

I am trying to model a switched mode power supply and I'm working on semiconductor losses now. I discovered how switching looses are affected a lot for diode's reverse recovery charge. The problem now ...
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1answer
124 views

Why to double reverse diodes in parallel to MOSFET?

I am building an H-bridge by this article. In the H-bridge MOSFETs IRF9530 and IRF530 used. By datasheet of Vishay both of MOSFETs have reverse diode inside the package. So by proposed schematics ...
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1answer
37 views

Why is there a “ - 1” in the pn-junction current equation

I was studying the Ideal Current–Voltage Relationship and was wondering why there is a "-1" in the pn-junction current equation for a pn junction diode.  Thanks in advance!
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1answer
173 views

choosing diodes for a passive ethernet hub

I found several guidelines for building a passive ethernet hub, mostly quoting this. The guide specifies which diodes to use, but I cannot find them anywhere. What are the parameters I should search ...
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3answers
270 views

Max voltage vs current for LED

There's some basic flaw in my understanding of how LED's or diodes in general work so hope someone can help and forgive the simple question. So generally when one has an LED in series with a ...
4
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4answers
276 views

Floating diode in a Sot23 package

I have a schottky diode in a sot23 package that is composed by 2 schottky diodes with a common catode connection. I need to use one of them. Should I let the second floating with unconnected pin or ...
3
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4answers
568 views

Does it mean voltage across diode is zero?If yes, then is zero voltage across diode condition for forward bias?

When an ideal diode is forward biased, it is replaced by a connecting wire .Does it mean voltage across diode is zero?If yes, then is zero voltage across diode condition for forward bias?
4
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3answers
84 views

What is the voltage source and ground on an antenna?

I've seen a few diagrams relating to AM demodulation, and I can't for the life of me figure out where the voltage source and ground come from in an antenna. From what I understand, an antenna can ...
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1answer
79 views

Diode selection [duplicate]

I have a very simple circuit but have no idea on what or how to chose a diode for it. It is for a uni project and we are being marked on our justification for choosing the diodes. Is there such ...
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1answer
158 views

What is is an “M7” Diode

I know what it is in general terms of course. But I mean specifically what does the M7 mean. I certainly can't just go to digikey and order an M7 diode because such a part does not exist. I'm making a ...
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1answer
92 views

Choosing a correct diode

I am trying to find a suitable diode to place on the wire that connects c and e in the circuit, with the cathode on the right hand side. I need to justify why I chose the specific diode as well. ...