Diode Definition and 555 Threads
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Need help with PIN diode selection in RF switching circuit
I have a project that calls for activating a passive RFID tag by applying a few volts, and a PIN diode seems to be what I need. I can insert it into the antenna loop, where it would prevent an RF signal from being sent unless a forward DC voltage was present. I only know enough about...- James Demers
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- Diode Rf Rfid
- Replies: 2
- Forum: Electrical Engineering
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Doubts on Diodes: Circuit Solving
What do i need to do for transfer characteristics for the first problem (B)? I plotted the ##V_1## and ##V_2## plot on the same graph: Is it correct? For the second problem , i guess the capacitor ##C_1## is just there to ensure AC flow . But really unsure how to approach this .- Bling Fizikst
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- Circuit Diode transfer
- Replies: 10
- Forum: Introductory Physics Homework Help
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Doubts on Diodes -- Why is voltage shifted by 0.7V?
I have just started diodes . What's ##V_{ON}## here? Could anyone explain what's going on in the graph? It seems like the one from the definition of half wave rectifier but shifted below the x axis by ##0.7##- Bling Fizikst
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- Diode Graph
- Replies: 7
- Forum: Introductory Physics Homework Help
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Find V-I characteristic for this circuit with ideal diode
This circuit has an ideal diode, which is modeled as That is, when the potential difference across the diode is ##\leq 0## then we replace the diode with an open circuit and no current flows through it; when the potential difference is ##\geq 0## we replace the diode with a short circuit...- zenterix
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- Diode Electric circuits
- Replies: 2
- Forum: Introductory Physics Homework Help
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Engineering Variation of parameters in this Diode-Resistor circuit
Circuit diagram- mazeem
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- Diode Electronics engineering Physics
- Replies: 1
- Forum: Engineering and Comp Sci Homework Help
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Why is Reverse Saturation Current Included in the Forward Bias Diode Equation?
Hi all, This is not homework help or something, it is my general query. I read that ideal diode equation is given as in above equation Is is the reverse saturation current or dark saturation current (According to this website). And according to most of the study which I did this reverse...- Muhammad Usman
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- Diode
- Replies: 2
- Forum: General Engineering
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I have a question about diodes and the PN junction
Is the PN junction inside a diode what makes the electrical current only flow in one direction and not in the opposite direction? If this is so, why does it happen? Also Why is the P-type material said to have empty holes and the N-type material to have free electrons?- Etherealist
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- Circuit Current electricity Current flow Diode Pn junction
- Replies: 2
- Forum: Electrical Engineering
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Engineering Power dissipation of 2 diodes (1 is a Zener diode)
Are my equations correct? And my process of how I should solved this problem?- Edy56
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- Diode equations Power
- Replies: 7
- Forum: Engineering and Comp Sci Homework Help
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Engineering Optimizing Diode Performance: Load Line Analysis
I have drawn the I-V characteristic graph of the diode. I am facing problems with drawing the load line. For what value of E (Source Voltage), should I draw the Load Line? To get the I-V graph, I had to continuously change E.- ARoyC
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- Analysis Diode Electronics Line Load load line source voltage
- Replies: 12
- Forum: Engineering and Comp Sci Homework Help
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Experiment about diode related to temperature and potential difference
(a) I know some of the apparatus needed for the experiment, such as DC power supply, ammeter, voltmeter, maybe rheostat. But I don't know how to change the temperature of diode. What is the correct and safe way to change the temperature of diode? Thanks- songoku
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- Difference Diode Experiment Potential Potential difference Temperature
- Replies: 11
- Forum: Introductory Physics Homework Help
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Why Does My Varactor Diode Test Circuit Behave Differently on a Breadboard?
In the circuit simulator there is no voltage at the Varactor cathodes when Vbias is zero, but depending on the Varactor I use on the breadboard it can be as high as 7.4 volts! There is minimal current through the series resistor when Vbias is applied in LTSPICE, but I always see a significant...- piepermd
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- Circuit Diode Test
- Replies: 93
- Forum: Electrical Engineering
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Understanding a heat sensor circuit?
What I understand is that the β parameter of the npn transistor is temperature dependent. Increasing the temperature increases the collector current and hence the LED turns ON. But I don't understand the resistor arrangement.Also I can see that the diode is keeping the Base-Emitter junction in...- Raihan amin
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- Circuit Diode Electronics Heat Sensor Transistor
- Replies: 3
- Forum: Electrical Engineering
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According to which criteria should I choose a laser diode?
Hello everyone, I don't know which laserdiode and lens system should I choose for my Project. It is all about AFM Microscopy with a cantilever ( Length= 450 um, width = 50 um and thickness= 2um). So as you see it is not a small cantilever. As far as I Know, the larger the cantilever is, a larger...- Aymangh994
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- Criteria Diode Laser Laser beam Laser diode Lens system
- Replies: 8
- Forum: Electrical Engineering
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Using delicate 5V IC to toggle 12V device with MOSFET, Diode, resistor
Hey all, I have a 5v IC that is triggered by a sensor to unlock the 12v lock, I am using a NPN transistor as a switch with the 5v VCC as the gate, I need it to sink back to the GND of the IC without blowing it, is this safe? If not what changes would you suggest, it has been years since I've had...- NotASmurf
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- 12v Device Diode Ic Logic gate Mosfet Resistor
- Replies: 8
- Forum: Electrical Engineering
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Two basic diode and capacitor circuits
Hi there! I have resolve this basic circuit, but, i have a little questions about. The first circuit its: The diode in all voltaje cases act like a switch, so, the courrent of all components and voltage of the resistance its zero. I graph the curve according my interpretation. My question its...- Noob of the Maths
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- Capacitor Circuits Diode Ohm's law
- Replies: 6
- Forum: Introductory Physics Homework Help
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Graph of waveform across diode shown by CRO
Option (A) and (B) is wrong because the waveform should be half-wave, not full-wave. But how to know whether it will be (C) or (D) based on the circuit given? Thanks- songoku
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- Diode Graph Waveform
- Replies: 11
- Forum: Introductory Physics Homework Help
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Troubleshooting Laser Diode Circuit with Arduino and PN2222a Transistor
Hi, all I have a circuit where the base transistor (PN2222a) leg is plugged into the pin 9 of the Arduino. When I power everything up and send the signal from the Arduino to the transistor base leg, the laser diode doesn’t light up, but my design strictly follows Complete Tech Guide to Laser...- Stonestreecty
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- Arduino Diode Laser Laser diode Transistor
- Replies: 10
- Forum: Electrical Engineering
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Can RF101 Diodes Be Used in Low-Frequency Recovery Circuits?
Hello! This is my first post. Problem to use RF101 Diode: There is little RF 101 diode that I can search for. And I have a project about the recovery circuit. but the frequency of the rectifier circuit is very low, it only has requirements for the withstand voltage. As long as the withstand...- GUOJINMIAO
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- Diode
- Replies: 7
- Forum: Electrical Engineering
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Space charge region of p-n junction diode
does np=ni^2 holds even the space charge region of a pn junction diode?- rkgjet
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- Charge Diode Junction P-n junction Space
- Replies: 1
- Forum: Electrical Engineering
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Understanding diode (LED) resistance at V=0
I'm working with some bare chip diodes for an application where I need extreme luminosity. These are the diodes here: https://www.irtronix.com/leuv-v625a6 I notice that some of the diodes have very significant resistance (on the order of megaohms) from anode to cathode and some have very small...- phillip_at_work
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- Diode Led Resistance
- Replies: 11
- Forum: Electrical Engineering
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Simulate Leakage Current - Reverse Bias Diode
hello I m Trying to simulate leakage current, say from a reverse bias diode I'm fairly how i can do it- cheniour oussama
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- Current Diode Leakage
- Replies: 7
- Forum: Electrical Engineering
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Calculate the voltage across a resistor using Thevenin's Theorem
I'm thinking I should apply Thevenin's Theorem to find the voltage, but I need to find I_D in order to be able to calculate U_S.- Andrei0408
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- Diode Electrical & electronic Resistor Theorem Thevenin Thevenin's theorem Voltage
- Replies: 4
- Forum: Introductory Physics Homework Help
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How to find the voltage threshold at which diode switches states?
I've attached pictures with the circuit and part of the attempted solution. I've replaced the diode with its offset model and obtained the equivalent circuit in the 2nd picture. After applying KVL, I've obtained that u_l=−u_D−i_D*R. Since U_D0 is greater than 0, I've deduced that the diode must...- Andrei0408
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- Diode States Switches Threshold Voltage
- Replies: 4
- Forum: Introductory Physics Homework Help
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Understanding PV Cell Modeling: Single vs Double Diode
I am looking at modeling a PV cell and I'm trying to understand the real difference between the single diode and double diode mode. I now realize that I don't fully understand the purpose of the diode in the model in the first place. I've just learned that it was there and went with it. I...- willDavidson
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- Cell Diode Modeling
- Replies: 11
- Forum: Electrical Engineering
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Diode Power Calculation: Understanding the Basics
Hello all, I've just started learning about diodes.. I believe I've done this problem correctly (question in black), although want to make certain I'm understanding the very basics before moving on. Thank you- WRS
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- Beginner Diode
- Replies: 4
- Forum: Introductory Physics Homework Help
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What type of diode is best for protecting batteries in a weather station?
It's a mod to a weather station which normally uses primary cells alone. There are four cells, connected as 2X2. I am providing dc power up there for another purpose so I thought it may as well supply the station as well. But I need to protect / isolate the batteries from the DC source with a...- sophiecentaur
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- Choice Diode
- Replies: 22
- Forum: Electrical Engineering
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B What Is the Physical Significance of Logarithmic IV Graphs in Diodes?
Hello there, I've been working through a task (that doesn't have an answer sheet or explanation) in which we plot I against V for three different diodes. Each has a different threshold voltage and displays the usual charcteristic curve. The final question is this: "It is suggested that the...- OwlsInATrenchcoat
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- Current Diode Diodes Graphs Logarithm Logarithmic
- Replies: 3
- Forum: Other Physics Topics
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Problem with this Laser diode circuit
I have dismantled an old DVDRW drive and taken a 4-pin laser diode from it. After connecting it to two 2A batteries (red with positive, and blue with negative), the light beam is diverging, and the brightness is even dimmer than another laser diode that I got from a presentation pen. Also...- tPS
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- Circuit Diode Diode circuit Laser Laser diode
- Replies: 8
- Forum: Electrical Engineering
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Semiconductor (Diode) Lasers and Properties
print ('Calculate threshold, power, slope efficiency for different lengths of SC Laser') g = 510 # The gain of the laser, arbitrary value of 510 m^-1 was picked I = np.linspace(0, 0.03,5) #DRIVE CURRENT; 100 values of current, 'I', between 0A and 0.03AV = 1.8 #INPUT VOLTAGE; arbitrary value of...- dalye13
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- Diode Lasers Properties Semiconductor
- Replies: 2
- Forum: Advanced Physics Homework Help
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Finding the potential difference of a diode
I've tried doing it but i haven't been able to find the resistance of the diode.- Ben1238
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- Circuits Difference Diode Physics Potential Potential difference Resistance
- Replies: 6
- Forum: Introductory Physics Homework Help
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Fundamentals of the PN Junction
Unbiased circuit (no driving voltage source) ************** Fig 1 The N-type material has a tendency to donate electrons to the P-type (i.e. absorb holes from) across the PN junction via diffusion current exclusively within the conduction band of both materials. It does so after those...- TJonline
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- Diode Fundamentals Junction Pn junction
- Replies: 12
- Forum: Electrical Engineering
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Why do people refer to the "fast axis" vs. "slow axis" of Diode Lasers?
This is really a nomenclature question. The radiation pattern of a typical laser diode has one axis with low divergence (the slow axis) compared to the other (the fast axis). I understand about antenna radiation patterns, spatial Fourier transforms (Fourier optics), etc. So I think I understand... -
B What is the purpose of the depletion region in P-N junction semiconductors?
I'm new to semiconductors. While I was studying types of biasing in semiconductors, here's what I read - 'In forward biasing, the width of the depletion region is reduced.' Here's what I thought - Since the potential barrier is reduced in the junction due to external potential, the diffusion...- Praveen1901
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- Diode Junction P-n junction Physics Pn junction Semiconductors
- Replies: 2
- Forum: Other Physics Topics
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Engineering Find the Thevenin Equivalent (Circuit with diode load)
- Rabeamoh
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- Diode Equivalent Load Thevenin Thevenin equivalent
- Replies: 4
- Forum: Engineering and Comp Sci Homework Help
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Engineering DC bias current and small-signal resistance
We are given that ##i_D = 8\cdot 10^{-12} (e^{v_D/20m} - 1)## Hence ##i_D' = e^{50 v_D}/2500000000## and ##i_D'' = e^{50 v_D}/50000000## Then I have that ##\delta i_D \approx\frac{ e^{50 v_D}}{2500000000} \cdot \delta v_D = \delta v_D / 5## Cancelling ##\delta v_D## from boh sides and solving...- JessicaHelena
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- Bias Current Dc Dc circuit Diode Diode circuit Nonlinear Resistance
- Replies: 3
- Forum: Engineering and Comp Sci Homework Help
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Diode passing voltage in both directions.
i connected a diode to a 4 volt battery. in 1 direction the diode passes 4 volts. in the other direction the diode passes 1.9 volts. is this normal? shouldn't the diode pass 0 volts in the other direction?- David lopez
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- Diode Voltage
- Replies: 20
- Forum: Electrical Engineering
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Schottky diode with the correct voltage and current rating
Non-isolated boost converter Input Voltage: DC8.5V to 50V Output Voltage: DC10V to 60V Max. Ouput Current: 12A Frequency: 150KHz- Sid55
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- Current Diode Voltage
- Replies: 9
- Forum: Electrical Engineering
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Engineering Calculating Voltage Drop Across Non-Ideal Diodes
So I have this circuit up above and I need to find the voltages across each of the diodes. The only info given is that they are identical silicon diodes at T = 300K. My first thought was that since the diodes are opposite, D2 would be in reverse bias and would act as an open. However, I realized...- marcadams267
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- Diode Drop Voltage Voltage drop
- Replies: 20
- Forum: Engineering and Comp Sci Homework Help
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I am confused -- how to bias the diode in a boost converter?
i have been researching how to build a boost converter. according to the articles i have read, when the switch is closed current flows through the switch to the negative terminal. when the switch is opened, the back emf from the inductor and input voltage add, which forward biases the diode. i...- David lopez
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- Bias Boost Boost converter Confused Converter Diode
- Replies: 23
- Forum: Electrical Engineering
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How does applying potential affect the energy band diagram for a diode?
Ref: http://hyperphysics.phy-astr.gsu.edu/hbase/Solids/pnjun2.html Hyperphysics Asstr Why does the band diagram shift up or down when I apply potential? Why does it shift down when positive potential is applied? Professor said it's because electron has negative charge and so we consider...- jaus tail
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- Band Diagram Diode Energy
- Replies: 3
- Forum: Electrical Engineering
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Engineering How Does a Capacitor Affect Ripple Voltage in a Diode Circuit?
Summary: Seek help with the working of a Capacitor in the presence of a DC & AC voltage source. I greatly appreciate this opportunity to submit a question. It's a homework problem and I only seek to clear my concepts. Problem: Find amplitude of the ripple voltage across the resistor...- wirefree
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- Capacitor Circuit Diode Diode circuit
- Replies: 15
- Forum: Engineering and Comp Sci Homework Help
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What is the design methodology of a Heatsink for a high-power diode?
In reference of Ned Mohan's book, I have designed a heatsink, firstly natural convection taken into account, but laboratory test results and theoretical calculations are not matching. The test results: For 40 A (means 62 W), 30 Celsius ambient temp, it raised up 51 Celsius. So, Rs-a =...- Ramazan Duzgun
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- Cooling Design Diode Heatsink Thermal resistance
- Replies: 5
- Forum: Electrical Engineering
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Novice question about Relays, Capacitors, and Diodes
Hello, In regards to this relay, TQ2SA-1.5V Panasonic 2 Form C AS Single side stable, 1.5VDC 2A DPDT NON-LATCHING SMD Relay https://www.mouser.com/ProductDetail/769-TQ2SA-1.5V PDF 1 of Relay PDF 2 of Relay (specifically pages 5-6) is attached at the bottom as a pdf file. I was previously told...- shushi
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- Capacitance Capacitor Capacitors Diode Diodes Relay
- Replies: 5
- Forum: Electrical Engineering
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A Is there a passive molecular flow 'diode'?
During high vacuum pumping, one sucks viscous gas out of a chamber down to just above the molecular flow density where viscous flow becomes absent, and then may employ a different sort of pump to start pulling in the remaining molecules: Molecular flow. I have been wondering for a while if...- cmb
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- Diode Flow Molecular
- Replies: 2
- Forum: Classical Physics
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Using a generator to charge 2 batteries
My project is to create a circuit for a stroller that can store the mechanical work into electrical while moving around and with the push of a switch, use the electrically stored energy to assist the movement of the stroller. I’ve tried capacitors but it ended up not being enough voltage and I...- Toeman123
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- Batteries Charge Circuit Dc motor Diode Electical Generator
- Replies: 58
- Forum: Electrical Engineering
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Is Ohmic Resistance Applicable to Diodes?
Well I was just wondering how ohmic resistance works in a diode . I mean let's take forward bias mode.In forward bias mode electrons are diffused from the n type region to the p type region.The depletion layer still exists but is very narrow.So according to Drude model of ohmic resistance...- CaptainMarvel1899
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- Diode Diode circuit Diodes Resistance
- Replies: 10
- Forum: Electromagnetism
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B What Happens When We Apply a 10V Source to a Diode in Reverse Bias?
Assume we have a diode . We connenct the negative terminal of the battery(anode) to the n type region and we connect the positive terminal of the battery to the p type region of the battery.The net force forces electrons to start flowing from the n type region to the p type region.As long as we...- CaptainMarvel1899
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- Confusion Diode Diode circuit Semiconductors
- Replies: 14
- Forum: Other Physics Topics
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Semiconductor physics: Voltage below forward voltage
Assume we have a diode closed circuit.We connect the p type region of the diode to the positive terminal of the battery(cathode).We connect the n type region of the diode to the negative terminal of the battery(anode).The voltage of the battery is 0.3V .The diode%s intristic se miconductor is...- CaptainMarvel1899
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- Diode Diode circuit Physics Semiconductor Semiconductor physics Voltage
- Replies: 4
- Forum: Electromagnetism
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Diode operation from reverse bias to zero bias
Assume we have a closed diode circuit .We connect the n type region of the diode to the positive terminal of the battery.We connect the p type region of the diode to the negative terminal of the battery.The depletion layer is increased.Now we open the circuit.Why the diode returns to its zero...- CaptainMarvel1899
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- Bias Diode Reverse Semiconductor Zero
- Replies: 7
- Forum: Electrical Engineering
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Load resistance in voltage regulator
Homework Statement [/B] I want to find the minimum resistance ##R_L## so as to maintain ##V_z##(voltage of the zener corresponding to the minimum current ##I_{z_0}##) across the same resistor ##R_L##. Homework Equations ##V_z##(voltage of the zener corresponding to the minimum current...- archaic
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- Diode Diode circuit Load Regulator Resistance Semiconductor Voltage Voltage regulator
- Replies: 3
- Forum: Introductory Physics Homework Help