Flow of electric charge - typically movement of charge carriers, such as electrons. Measured in amperes (A).

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2answers
61 views

Does current flow stop when a capacitor is fully charged?

If I take a 1V battery and a 1 farad capacitor and a bulb and connect them in a circuit. Then will after the capacitor gets charged (not fully charged as that is impossible) will the bulb gradually ...
0
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1answer
30 views

Effects of C Rating on Battery Life

A polymer lithium ion battery is rated at 3.7v, 6600mAh and a maximum discharge current is specified at 3.3A. I take it this means the battery can be discharged at 3.3A and last for two hours since ...
0
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1answer
40 views

RGB LED Strip - several question from newbie

I've just bought 5 meters long 12V analog RGB LED strip and I'd like to turn it on! There're 60 LEDs per meter so, totally 300 LEDs and each LED consumes 20mA. Here're my questions. From internet ...
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1answer
54 views

Measuring Current in 12V DC Fan

I am trying to measure the current of a DC computer cooling fan (Intel E18764-001) at various volts. Its rated specs are: 12V 0.20A. Check it out here. So I am suspecting that this is telling me: ...
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3answers
177 views

Direction of current through a circuit with multiple batteries

So I've got a bit of a problem trying to understand this circuit in my physics book. If current flows in the direction of the three arrows (I1, I2 and I3, couldn't find a way to name them) how can ...
0
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1answer
31 views

What should my priorities be in designing a home generator?

I have a few basic electrical engineering questions. My purpose is a home wind/ hydro electric project to sell back to the grid. My questions are these: 1. Which generates greater power: running at a ...
1
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2answers
112 views

Is it possible to amplify near zero signals?

Is there an amplifier has an ability to amplify any signal down to -500 dBm? If there is not, can it be possible? If it is not possible, what is the weakest ever signal that can be amplified?
0
votes
1answer
67 views

Calculation of base current resistor resistance for a transistor operating in switch mode? [duplicate]

I have a 9V DC motor and I want to control its speed with an Arduino board with help of a power transistor TIP120. In one of the web-tutorials the writer explains how to calculate the resistor ...
0
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1answer
60 views

How to limit motor stall current?

I've run into a dilemma. I have two motors, both with a 2.2A stall current. I know that at start up, motors will draw their stall current because they are essentially stalled. However, my motor driver ...
0
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1answer
52 views

Current loop Converter

Is it possible to convert a 2 wires current loop to RS232, and from RS232 to current loop, I am trying to put an RS232 sniffer in the middle so I can see what they are communicating to each other. I ...
0
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0answers
31 views

Energy Monitor IC with built in Hall Sensor

I have looked at a couple of IC's which provide energy measurement(real power,apparent power), however these need to interfaced to a current transformer or a hall effect sensor since they cannot ...
3
votes
2answers
56 views

Options for higher current regulation in an aircraft strobe system

I've deployed a homemade strobe system using Cree 10W LEDs in my homebuilt aircraft. My implementation uses a simple PIC controller to do the flashing, an IRL2505 mosfet (driven by an NPN transistor) ...
0
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1answer
57 views

Multiple shunt resistor INA226

For a project I'm trying to build a measurement tool for USB where I can measure U, I and P using the INA226 from Texas Instruments. The shunt resistors all have a different value to measure a ...
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2answers
70 views

Do I use a 5V 2A or 3A DC adapter to power my 2m (6.5ft) WS2801 LED strip?

(Please excuse me if my English is bad) I recently purchased a 5m LED strip, but I only need to power approximately 2m (6.5ft) of the 5050 RGB LED WS2801 strip, but I'm afraid that a DC power adapter ...
2
votes
2answers
231 views

What determines a load's current requirements?

Apologies if this question has been asked before. I'm sure it has but hard to find as wording of question may not bring up the duplicate question. Let us say we have a 10 ohm resistor as a load. ...
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2answers
35 views

Joining a raspberry Pi to an external hard disk cage power supply

I have an external SATA hard drive enclosure that has its own power input. I would like to be able to run a Raspberry Pi from the same power input. The enclosure takes a 12VDC input (currently I'm ...
0
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0answers
40 views

Odd MOSFET behaviour (in Multisim)

I have this circuit that's behaving in a strange manner. I am getting a surprisingly low current value flowing through the inductor when the path includes the N-channel MOSFET. Please could someone ...
0
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2answers
53 views

Are all solenoids waterproof?

I have an application where I need a solenoid to control a valve at the bottom of a tank. For unimportant reasons the valve needs to be inside the tank at the bottom. I was wondering are all ...
0
votes
1answer
85 views

Solar panel and 120mm Computer fan

Just before I start description my question, I would like to let you know that I am new at this. I am working on a solar air heater for one of my window. I've been researching and reading up on a lot ...
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0answers
75 views

current of inductor, a nice challenge

My professor calculate current of inductor in t=0^+. he calculated -1/30, but i reach to +1/30. anyone could help me? Note: (IL(0-))=0
-5
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1answer
45 views

Calculate Current [closed]

how to i calculate current( Before Resistance ) from these parameters Voltage before Resistance Voltage after resistance Resistor Value Current After Resistance
5
votes
2answers
221 views

Transformer current peaks

So I am designing a power supply, got everything calculated, and decided to simulate it for a second to see if the smoothing caps keep the voltage above the regulator limit at max current draw. What I ...
0
votes
1answer
75 views

Series and parallel transformers?

I have two different transformers. The output of the first one is 15 volts and 1500 mA. The output of the second one is 5 volts and 500 mA. If I connected them in series (to get 20 volts) what will ...
0
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1answer
81 views

Relay that detects 240VAC and switches 12V DC

I'm wishing to detect the loss of AC power (in this case 240V) and when this event occurs have a 12V DC circuit go to earth. This will trigger an alarm for users to react to situation. Can anyone ...
0
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1answer
70 views

Graph of Second-Order Circuit

I know that a circuit is second-order circuit if there are two storage elements. I used pspice to simulate and I got this graph I feel like it is not correct. Please tell me my mistake. when there ...
1
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3answers
133 views

Sin signal from PWM

I wrote a program in order to use Pulse Width Modulation to simulate a sinusoidal signal. Added a low pass filter to get rid of the noise and the traces of it being a discrete signal. Added a half ...
0
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1answer
39 views

What is the current flowing through this switch?

I am looking at a circuit diagram like this: simulate this circuit – Schematic created using CircuitLab Switch 1 and switch 2 never are on at the same time (they alternate) I turn on S2 ...
0
votes
1answer
46 views

Calculating a voltage and power dissipated in a circuit after creating a supernode

I am looking at this circuit and I am trying to calculate Vx and power supplied by the 1A source. I believe my calculations for node V2 are correct but I am not too sure about my V1 and V3 supernode ...
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4answers
53 views

Voltage regulator (LM350) gives no current

I am trying to use a Fairchild LM350 to get 8 volt output. I am using basic circuit (page 5 of datasheet) to do that. I get the voltage I want but whenever I try to measure the current (by putting the ...
1
vote
2answers
67 views

Shape Memory Metal framed sail

I am working on a costume prop that utilizes a triangular cut sheet of emergency blanket spined with a single 12" long, .04" dia piece of nitinol wire that has a transistion temp of 115deg F. My plan ...
1
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3answers
187 views

How to calculate current going through an LED

I'm a beginner to electronics. I want to find out how to calculate the current in the following circuit. (I know how to calculate total resister value in serial and parallel resisters in order to ...
1
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1answer
211 views

Is there a good physical model for what happens when a light bulb suddenly goes out?

Sometimes a light bulb just stops working and goes dark for seemingly no reason. Can Dirac δ impulse to a light bulb serve as a mathematical model for what happens so we can assume that the electric ...
0
votes
1answer
28 views

Replacing an AC power supply that is 2 volts higher than the original but has the same current rating [duplicate]

I have an audio mixer that requires an AC 16 volt 1 amp external power adapter. I need to know if an 18 volt 1 amp AC external power adapter would work without damaging the audio mixer?
1
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4answers
119 views

Ohm's law clarification

I am slightly confused about Ohm's law. I understand V = IR, and I did a simple experiment on paper. The results are slightly confusing, so I was hoping someone could tell me if I'm right? First, I ...
-2
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2answers
76 views

Can we measure a electricity? Embedded System? [closed]

Checking if electricity is passing through a wire or not using embedded systems. I want to check if power is there or not. I am new to embedded system. If yes how can I check.
0
votes
1answer
71 views

Current over CAT6 ethernet cable

How much current can a CAT6 cable reliably handle? I want to use 3 of the cores for +5V and 3 cores for GND. I'm wondering at what current I need to think of another power solution.
-1
votes
0answers
66 views

Interface WCS2702 Hall-effect current sensor with Arduino

I am planning to use below current sensor WCS2702 (0~2A) rated measuring circuit. Since its sensitivity is very low. How to make detect by Arduino analog pin? Or how can I convert the low voltage to ...
1
vote
3answers
132 views

Simple Ohm's Law Question

Do I need a resistor if \$\frac{V}{I}=0\$? I am working on a simple circuit of an LED and a buzzer in series where the voltage drop would be 2 and 3 volts, so \$R=\frac{V}{I}=\frac{(5 - (3 + ...
2
votes
4answers
221 views

Current sensor measuring circuit

I am planning to design Rshunt basis current measuring. My current measuring range is 1A~2A. I need analog output of 0~5V analog with 1% accuracy. How can I do this? I found conversion circuit here. ...
1
vote
2answers
68 views

Emitter Follower Current Gain

I have two electronics textbooks and for some reason, both of them just gloss over configurations that are not "Common Emitter". Regarding the emitter follower, I understand that there's no voltage ...
-1
votes
1answer
74 views

Input 5V 100mA, output 200mA

I am new to electronics. I have come across a problem which I face. Will need some advice from here, as I am a student and would like to know: is there any way I can increase current in a circle. ...
0
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2answers
48 views

Unidirectional current and bi-directional voltage device

Which is that device which can take in current in one direction irrespective of the voltage polarity across it? ( We can rule solid state switches - diode, SCRs etc).
1
vote
1answer
73 views

How to draw constant current independent of voltage for capacitor testing

I have a 150 farad 2.7 volt super-capacitor. I want to test the cap under various loads, .1 amps, .5 amps, and 1 amp. I will be creating a graph of the voltage over time. How can I constantly draw ...
1
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3answers
76 views

Can't find the correct voltage and current source

I'm trying to self-study this problem but I got stuck. What I tried to do: The equivalent resistor R1 for the 12 and 4 ohm resistors is 3 (12x4/12+4). The equivalent resistor R2 for the 4 and 12 ...
0
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1answer
43 views

Max Current Output [duplicate]

Looking around at a couple of power supplies that I own such as a guitar pedal adapter that says it puts out 9V and 1700mA max, how does a power supply like this work so that it doesn't put out too ...
0
votes
2answers
66 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 ...
0
votes
4answers
124 views

Can voltage be controlled in a fixed DC circuit?

If resistance is fixed in a DC circuit, can voltage still be controlled and changed from one value to another? Imagine this circuit, that has a fixed resistance of 1 Ohm, and the desired current is ...
4
votes
5answers
635 views

How does this constant current sink actually work?

So I have implemented a constant current source and it works wonderfully, but I was just hoping to try and understand it a little bit more! Here is the circuit in question: I have tried doing some ...
3
votes
1answer
77 views

Continuous current capacity of this conductor?

How much current can a copper conductor that is 2 meters long, 0.003m thick, and 0.00045m wide continuously carry? Also, the resistance is about 0.02 Ohms.
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0answers
32 views

Problem with DAC with current mirrors

I'm trying to design curent steering DAC with binary weighted inputs - I'm using M4, M5, M6, M7 to copy the reference current flowing in M8 with coefficients of 1,2,4,8. The idea is to put either 0 or ...