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

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19 views

Charge pulse to current conversion

I have a photodetector device that outputs charge pulses proportional to incident light. From the device's datasheet (here) and some infor provided by the manufacturer (here), I've understood that ...
3
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3answers
94 views

Are \$\frac{1}{4}\$watt 4x\$\Omega\$ Resistor and \$\frac{1}{2}\$watt x\$\Omega\$ Resistor equivalent?

We know Ohm`s law: $$\Omega = \frac{V}{I}$$ $$W=\frac{A}{t} \space\space\space\space\space\space V = \frac{A}{q} \space\space\space\space\space\space I = \frac{q}{t} \space\space\space ...
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0answers
10 views

Sensor analog output changes while using Xbee

We are using a adafruit noise sensor for activity detection. We have setup it with Arduino Promini. It works well. But when we attached Xbee Pro S2B with our setup, the analog reading of noise sensor ...
-1
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0answers
33 views

Erogation of current in Mosfet during saturation [duplicate]

When a nMOS transistor operates in the saturation region, its channel is pinched-off, as shown in this image and this image. So, the channel does no more connect the source with the drain, but a ...
0
votes
1answer
16 views

How do I design the maximum current curve for a stepper motor?

I want to drive a stepper motor (0.89V/5A) with the L6470H-controller. There I have to set different values for controlling the maximum voltage each for holding, running, speeding up and slowing down ...
0
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3answers
66 views

What happens when I use a battery with too much current?

I am working on creating a line-bot from a book and it calls for a 6v, 1AH battery. I have these NiMh AA batteries that are rated at 2.3AH, 1.2v. Is there a way to set these up safely for the bot? ...
0
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0answers
34 views

If a sensor has both voltage and current outputs, how to calculate Vgs of the E-MOSFET?

If a sensor has both voltage and current outputs and connected as the Vin at the gate of a EMOSFET, how do I calculate the Vgs of the E-MOSFET? The Vout goes as the input for a microcontroller, where ...
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votes
2answers
82 views

Voltage vs current vs resistance - did I understand them right?

I'm currently getting started to learn about electrical engineering, and I'm having some difficulty separating voltage from current. I have seen a couple of times that a battery is compared to two ...
0
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0answers
31 views

Why does a photosensor affect the power factor of an LED

Using a kill-a-watt meter I measured the power factor of my LED light bulb to be 0.60. I then screwed the light bulb into a photosensor that turns the light on at dusk and off at dawn. I re-measured ...
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2answers
49 views

Differences between current sources transistor and current mirror

In this configuration simulate this circuit – Schematic created using CircuitLab if the two pMOS are equal, they provide the same drain current to both the branches: suppose that Vbias ...
1
vote
1answer
170 views

What is the input current of the 74HC595?

I need to calculate the power consumption of my circuit, but I can't find any information about the input current of the 74HC595. I drive the 74HC595 with the atmega8 on 5v, but what is the input ...
11
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4answers
2k views

Is current flowing backwards a bad thing?

In the circuit below: I find it awkward that the direction of the current on the 2V power supply is running opposite to the direction of the current on the 5V power supply. In the 5V power supply ...
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0answers
42 views

How do I calculated total current on each line with an even number of circuits (unbalanced)

In the first example I was calculating the current each line would see for the purpose of sizing wire. An EE told me my calculation was wrong and that phase A would see 74A not 64A. I'm wondering ...
0
votes
1answer
51 views

How can I calculate the maximum current a circuit needs?

I want to add a fuse to a self-designed circuit, but for that I need the maximum current of the circuit. In this circuit I have some ICs, some resistors, some LEDs and some capacitors. When I want to ...
0
votes
2answers
88 views

Fuse: why does it connect in parrallel with resistor?

I have a wire in normal condition runs 4A. The device I am using is auto-transformer, and its data sheet recommend to use fuse of 10A. So I went to buy the 10A fuse, and mount it onto a fuse holder. ...
1
vote
1answer
46 views

How switch 20A AC between 2 wires

I'm trying to translate a circuit I made from breadboard to PCB and need some help finding out what components I should be looking for. Basically, so far I have a very simple circuit running 12V AC, ...
0
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1answer
33 views

Current loop transmission using 3 - wires

Is it possible to transmit 4-20mA signal using 3 wires without external power supply (using the loop power supply)?
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0answers
36 views

Merging Current and Voltage sources - How can I do this?

I wish to power a +-12vdc pump which needs 300mA to drive the motor using a National Instruments USB-6009 data acquisition unit. The output of this device is limited to 5V and 5mA. I have two ...
0
votes
3answers
45 views

Switch current rating AC vs DC

I'm looking for a high current DC switch (able to switch something like 5V@30A) and I've encountered several DPDT that might do what I need, however they are only rated for AC applications (3A@250VAC ...
5
votes
3answers
581 views

How to deal with low space and high current?

In my circuit I am using a stepper motor driver, providing me up to 3 A current per trace. Thus I calculated the required trace width with a trace calculator, which told me to use a trace width of ...
0
votes
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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votes
1answer
36 views
0
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1answer
58 views

AC current terminals

I have a question that has really been eating up my mind since High School on Ac current and voltages, If its really true and i know it is that Ac current terminals keep alternating at a rate of 50 Hz ...
1
vote
1answer
33 views

discharge of capacitor through a current source

Assume we have a cap connected to a current source that draws a current \$I_0\$. What time would it take to discharge the cap by a voltage \$V_t\$? $$t=\frac{C \times V_t}{I_0}$$ Is this correct ...
0
votes
2answers
57 views

how to compensate power drains in dc circuits?

This has been on my mind for a while. Lets just take any electronics device. Lets say a mobile phone or a laptop. They have fixed voltage and current, but some components needs higher voltage/current ...
0
votes
1answer
41 views

Current output of a solar panel when connected to battery and load

I am trying to build a microgrid (final year project) where a 100-250 W 48V solar array will charge a 24V battery bank and a couple of 24V loads (40W lights, 60W fan). Batteries used (7 of this in ...
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2answers
33 views

Help with sensor output and data sheet

Here is all the circuitry I have. I only found thisdata sheet which may be for this anemometer: http://www.synchrodan.hu/letoltes/kriwan/kulsoerzekelok/szel/N292_INT10K_69000248_e.pdf What I ...
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0answers
56 views

RGB LED array without current limiting resistors but PWM

I found this blog post, where it says: Alternatives to using current limiting resistors: Resistors are a simple way to limit current, but they are not efficient. Excess power is wasted as ...
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0answers
114 views

Why output current shoots up by 10x

Here is my hand cranked generator for charging a high voltage capacitor. How the system is designed to work is shown in the following image: It is designed to charge the 10 mF capacitor to upto 50 V ...
0
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0answers
37 views

YHDC current sensor generats inaccurate values after hours , arduino

I am using YHDC SCT013 current sensor with arduino for monitoring the current profile of washing machines and using adafruit datalogging shield for the SD card and for the Real Time Clock. The ...
0
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0answers
20 views

What proved Conventional sense wrong? [migrated]

What fact proved for the first time that the conventional sense of current was wrong? And when it did happen? As a corollary of this question, why do we say that electrons have negative charge? Is it ...
1
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2answers
66 views

Does a hole through small gauge wire affect current and voltage to the source?

I put a hole with a staple trough a small wire (with the black stripe). The line is coming from a solar panel, so not sure if that changes things....? How will this effect current and voltage?
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2answers
46 views

Hot ENC28J60 Chip

I need some help figuring out why my ENC28J60 Chip is running hot. This is my first time using the chip and I'm not sure if I have everything right schematic-wise. I'm working on a prototype pcb I ...
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2answers
41 views

What would be the voltage across a load at a junction point where two current sources are connected in series?

If two current sources are connected in series,then what would be the voltage at their junction point across a load?
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votes
0answers
34 views

230 v to 24 v transformer mac load and cable size and length

I have 230 to 24 v toroidal transformer (500VA, 24 A) i need supply for our electronic calculator 24 v , now i saw some document which is saying i can take three parallel out put from transformer each ...
0
votes
2answers
31 views

Need help reading mosfet Safe Operating Area graph

Im trying to figure out the current limitations of a mosfet(SISA18ADN) I'm planning to use to check how much headroom I have. The datasheet states Continuous Drain Current that it can handle as ...
0
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0answers
48 views

Calculating capacitance at resonance

Could someone help me please asap, New to this ! Thank you! working out for the first one , could someone confirm? first question has been confirmed thanks Second question confirmation? thanks
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1answer
54 views

How do current spikes effect component lifetime?

My Master's thesis project works with a system that mechanically prevents a DC motor from stalling and effectively thresholds the amount of current the motor draws and removes large current spikes ...
2
votes
2answers
70 views

Modelling current to remain in particular range for fixed simulation time

I am a novice in SystemVerilog. I wish to know how to model a 8-bit signal X to attain four levels for certain ranges of time. For example,let the legal values of X be from 40 to 80(40 < X < 80) ...
0
votes
1answer
69 views

Explain currrent and voltage in this circuit?

Please help me to understand.According to me if there is no voltage drop across an element the voltage at its trailing end must be same as the supply voltage. 1: http://i.stack.imgur.com/LW32B.png ...
3
votes
1answer
38 views

How to select a DC cable connection type based on current?

I have a battery and DC-DC converter solution that I've ordered. The solution will output 20A continuously at 5V, and will sometimes pulse up to 30A for durations up to 10 seconds. I believe voltage ...
0
votes
2answers
51 views

How do I determine terminal characteristics of a dc motor with known torque and angular velocity?

How do I determine the terminal voltages and currents that will be produced by turning a dc motor at a known angular velocity and a known torque? I know that for a dc motor, the load torque has a ...
0
votes
1answer
60 views

Power Supply For CNC Setup

I can't quite wrap my head around the power requirements for a CNC setup i'm building. I'm using 3 x Easydriver 4.4 for driving the Sparkfun Stepper Motors. I previously used a 22 V 800ma Power ...
-1
votes
3answers
110 views

Efficiency of high-voltage power lines

If it is more efficient to have high voltage, low current power lines, why aren't homes and appliances adapted to accept high voltage and low current (and remove the need for transformers)?
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votes
2answers
70 views

How to calculate power requirements of LED matrix, per row or per LED?

I have built an LED matrix (9x9) and want to run it with Arduino. I am using technique of scanning, lighting up 1 LED at 1 time. The more I am reading about power requirements of a matrix the more I ...
-1
votes
1answer
76 views

“Sort the volts and the amps will sort themselves” [closed]

I once heard this quote: Sort the volts and the amps will sort themselves. Obviously there is much more to electricity than this, and you cannot just ignore current, but is there any element of ...
0
votes
1answer
53 views

Adding phasers in a parallel circuit problem

Below is a practice question that I am having trouble progressing further with. The (abbreviated) question and progress as follows: A circuit of 90V's supply is in parallel with two branches. Branch ...
0
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2answers
110 views

Current divider and capacitor

I have this circuit which looks like a current divider but with an extra capacitor. I want to know how Ia , Ib, Ic change as the capacitor begin to charge, i do know one thing after a time of 5 RC the ...
2
votes
9answers
2k views

How is it possible to have high voltage and low current? It seems to contradict the relationship between current and voltage in E=IR

I have read different forums and watched a few youtubes (in addition to my textbook readings) and the explanations seem to fall short. The issue seems to be how we are first taught about a direct ...
0
votes
3answers
52 views

Flexible long wire for high currents

I have an ATX power supply which has got multiple 5v outputs (at a maximum 40 amp current). I am willing to use it to power up a moving mechanical system 5-10 meters away. The problem is that since ...