Tagged Questions

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

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1answer
33 views

Current overlap in Inductive Smoothing?

I have the following circuit implemented in the lab : And the output was : Can anyone explain why the current overlaps here ? I can't make sense of this.
0
votes
1answer
50 views

Is accelerometer taking as much power (current) as it needs? [on hold]

I want to connect accelerometer to an oscilloscope. I have 3x AA rechargable batteries (2550mAh). I was told that e.g. microcontroller knows how much amps should it take and it wont burn if I ...
1
vote
2answers
126 views

Current capacity of wires

So this question stems from a previous question. Here Where from several tables one can see that the maximum current (Imax) is proportional to \$1/R\$ where \$R\$ is the resistance. (Or that ...
-2
votes
1answer
33 views

CT and ADC interfacing [on hold]

How to interface a CT (Current Transformer) with an A/D converter ? I have searched but could not find perfect solution, Are some possible solutions: CT + Burden Resistor + Rectifier + filter ...
0
votes
0answers
21 views

Datasheet for Keyes IR Transmitter (KY-005) wanted

Can someone help me find the datasheet for the Keyes IR Transmitter (KY-005)? I know how the pins work, I just need to figure out its voltage drop and how much current should go through it. Thanks! ...
3
votes
1answer
73 views

What external factor could cause increased current draw?

I have a metal cased device powered by 2x 1.5v AA batteries with a standby current draw of 19.7 microAmps. If I then cause a build up of static by shuffling across a synthetic floor and touch the ...
-1
votes
0answers
36 views

Need 2.1 Amps from a USB wire for my lighthing conector [duplicate]

I have been working into an ipad Conector, that seems to work FINE its plugged to a 5v 12A switching power supply, this goes to my PCB where it has up to 4 outputs, each output for 1 ipad Air, up to ...
0
votes
3answers
54 views

Current Source Circuit Internal Impedance

So I've been learning about current source circuits - this one in particular. I'm told that an ideal current source should give out the current no matter what happens to the load. But it should also ...
0
votes
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 ...
0
votes
1answer
71 views

What is the path taken by the back emf current?

! Where will the current flow through? If ON current(back emf "current") will loop through A B and C If OFF current will(back emf "current") loop through x y and z
0
votes
0answers
55 views

Calculate current in an series RC circuit with a DC square wave source?

Am still a noob in electronics so bare with me, In the image bellow how is the voltage drops found and the current in the meters, what is the formula? and if instead of a capacitor an inductor is used ...
1
vote
1answer
48 views

LEDs in parallel, strange current consumption

I just wired a blue LED on a breadboard with the anode to an Arduino Uno's 3.3V rail and the cathode to a 220 ohm resistor to ground. Then I measured the current consumption using my Fluke 87-V and it ...
1
vote
1answer
36 views

Current Leakage calculations regarding shock hazard. A complete picture?

There is a quantity called current leakage which has always confused me. By reading various definitions, it seems to be the current flowing through the ground circuit of a device (whether this be an ...
0
votes
2answers
89 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
votes
1answer
43 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
votes
1answer
45 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 ...
0
votes
1answer
65 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: ...
1
vote
3answers
181 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
votes
1answer
32 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
vote
2answers
116 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
78 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
votes
1answer
62 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
votes
1answer
53 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
32 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
57 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
votes
1answer
58 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 ...
0
votes
2answers
74 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. ...
0
votes
2answers
36 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
votes
0answers
41 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
votes
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
88 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 ...
-1
votes
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
votes
1answer
46 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
225 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
76 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
votes
1answer
82 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
votes
1answer
71 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
vote
3answers
139 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
votes
1answer
40 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
48 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 ...
0
votes
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
vote
3answers
188 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
vote
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
vote
4answers
121 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
votes
2answers
77 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
75 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
vote
3answers
133 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 + ...