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

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2answers
102 views

Doesn't voltage on ground make it not ground anymore?

simulate this circuit – Schematic created using CircuitLab Beginner here, trying to learn enough to start using a microcontroller. If the I/O pins are internally high, wouldn't pressing ...
0
votes
2answers
63 views

How to measure current with an analog multimeter?

I need measuring the current through a dc motor with an analog multimeter, but I don't know how to select the correct function to that. The meter is a FT-360TR. I know it can measure currents of ...
0
votes
1answer
32 views

connecting 2 GNDs with relative voltage difference

I have USB ground and Lab Voltage Source ground, for which I need common reference. I thought I could just connect them together, but I found, that USB ground is relatively higher than Voltage Source ...
0
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1answer
62 views

by touching neutral why we are not getting shock

According to Benjamin Franklin,current flow from +ve to -ve terminal but after joseph thomson it is desided that current flows from -ve to +ve,so in ac also neutral provides return path but why its ...
0
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1answer
53 views

3A Current Distribution

simulate this circuit – Schematic created using CircuitLab I am using a 5V 3A wall adapter. I have stripped the output end and connected it to a terminal block. I am rerouting the current ...
0
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2answers
60 views

How much is the gain of this Op Amp?

I have a circuit like this. I want to calculate the gain of this circuit. If there is no R4 then it is easy to calculate.But now I have a problem. If I have a input current I=0.5A, then what is the ...
2
votes
1answer
40 views

Trouble calculating time to drain a capacitor

Introduction I'm having trouble producing an equation that involving my MAX756 boost chip, a load and my 1.5F capacitor. Basically I'm trying to find out how long it would take for a 1.5F capacitor ...
0
votes
1answer
43 views

Need help with gaining some basic intuition regarding transmission line traveling weaves?

I always thought about current traveling through a wire much the same way marvels would travel inside a hula-hoop (all moving at the same time from one end to the other). In this simple scenario, ...
1
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1answer
41 views

Magnetic contact circuit

Which is the best circuit for using a magnetic contact for turning on a LED strip? I would like to turn on a strip led with 12V 7A battery, but: 1 - if I use only the magnetic contact it will be ...
1
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2answers
63 views

How to read datasheets for TTL logic gates regarding maximum output current conditions [duplicate]

From what I have been reading, the input stages to BJT TTL logic gates are emitter terminals of transistors. As such, when the input to these gates is logic low the base-emitter junction of these ...
0
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0answers
46 views

Use an 800 ma stepper motor with a 500 ma uln2803

Is it possible for me to use this stepper with this IC? I am using the second schematic on this page. I do not want to use the transistors in series if I don't have to. Thanks.
1
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3answers
378 views

Does a given size wire have a maximum power or a maximum current that it can transmit?

I've lost my 'intuitive feel' for current, voltage and power in a conductor (like a 18 gauge copper wire)... The wire seems to be rated by maximum current rather than maximum power... Does that mean ...
0
votes
1answer
35 views

Is Motor KT Linear with current?

This may be a little basic for some. Sorry in advance... I would like to use a large 3ph motor to perform a fast, controlled, stop. The rated motor torque is 850Nm @ 242A. My inverter claims to ...
0
votes
0answers
11 views

PM Synchronous motor Id-Iq current control

I am trying to implement the current control (Id, Iq) of a four pole PM synchronous motor. I am having trouble in making the Iq current follow a set reference. I had also implemented a cascaded ...
0
votes
3answers
91 views

How can this circuit read a value for amps at 0 volts

I made a simple circuit using this: It can tell you the voltage and current along a wire if you mouse over it. The wire down the bottom reads 4.55mA and 0V (the little yellow dots actually move to ...
0
votes
4answers
169 views

How do I explain current and voltage to a lay man?

A man asked me this question in suburban train when I told him that I am an electrical engineer. Of course I replied him that current is the flow of electrons and in order for the current to flow ...
0
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2answers
72 views

Flow of electrons when two charged plates are connected by wire

I have kept two charged plates(one positive and one negative) in contact with one another.So excess electrons will flow from negative plate to positive plate.But then why the wire joining the plates ...
1
vote
1answer
42 views

MP3-25 flexible solar panel providing low current

I am working on a project where I need about 20 mA to come from a particular solar panel I am in possession of. The solar panel is an MP3-25 panel, I actually have 2 which I am trying to get to work. ...
3
votes
0answers
188 views

Positioning of a resistor [migrated]

Apologies in advance, my electronics knowledge is very poor. I've got myself a resistor that I believe is appropriate for the job I want to do on my vehicle. I'm replacing the factory sensor; there ...
1
vote
2answers
74 views

Are my zener concepts wrong?

If a battery of 60v with internal resistnace 4kohm (in series) is connected to a zener diode of v_z=10v in parallel and a load resistance of 2kohm in parallel too, what will be the currents in ...
1
vote
1answer
136 views

Weird voltage measurements on transistor

Just as an experiment, I decided to put together the following "circuit": I then went ahead and measured Vbe, Vbc and Vec and this yielded the following results: Vbe = 0.602 V Vbc = 0.589 V Vec ...
0
votes
1answer
51 views

Capacitor discharging dilemma!

Let us take a capacitor charged by a source voltage of 12 V d.c. supply. Having fully charged, the capacitor is now connected with a source voltage of 5 V d.c. supply. What will happen to the ...
0
votes
1answer
49 views

How to supply 5 to 12v amplifier LM386

I started electronics recently and I'm trying to make the most basic mp3 amplifier. First I tried to make the amp myself with reused electronic parts but I didn't succeed... Amplify speaker with 9v ...
0
votes
1answer
40 views

Voltage source connected to a MOSFET source

This circuit simulate this circuit – Schematic created using CircuitLab where M1 is an n-channel MOSFET, is said to be incorrect. If the voltage Vin should be imposed to the source ...
2
votes
3answers
120 views

Whats the effect on Voltage and Amps when 244 9v batteries are connected in a series?

There are many opinions about a stunt a guy did on youtube, where he connected 244 9v batteries together in series. Can someone clarify the magnitude of Current being limited by the chemical ...
0
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0answers
52 views

voltage and current amplifier

voltage amplifier does voltage amplification current amplifier does current amplification Is there something like power amplifier or power amplifier is just same as current amplifier?
1
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2answers
40 views

Combining voltages sources to increase current

So I know when current is divided among parallel wires, you can combine them to one current at the ends. My question is can I combine a circuit with 3 sources in parallel to get an increase current? ...
1
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1answer
38 views

Electrical continuity detection [Manufacturing Solution]

I am designing a testing box that has as a specification supplying power safely to a product range that requires the following voltages: 24Vdc, 24Vac, 110Vac and 230Vac. I am intending to use ...
0
votes
1answer
56 views

More Current from GPIO

I'm working on a project that uses a GPIO port extender, but I need the ability to sink more current on the GPIO pins. There are 24 GPIO pins. Each pin can either be input or output. The pins ...
0
votes
4answers
105 views

Confusion about current and voltage

I have been learning about electronics as a hobby. And I'm still confused about current and voltage. I've read many sites and watched many videos. But still have questions. Here is what I learned so ...
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votes
2answers
104 views

Is 20 watts of electricity dangerous?

I have a few circumstances which invlove someone being shocked with 20 watts of electricity and whether it would be deadly. So here they are: Would 1000 volts at 20 miliamperes of AC (2MHz ...
-3
votes
1answer
40 views

what is minimum amount of current to charge a battery, suppose if we connect 150 AH Battery to UPS? [closed]

This is anji, If we use a battery with ratting 12v C10 in UPS then what is the current value to charge the battery?
0
votes
1answer
35 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
votes
3answers
100 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 ...
0
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0answers
13 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
votes
0answers
38 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
20 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
votes
3answers
72 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
votes
0answers
38 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 ...
0
votes
2answers
87 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
36 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 ...
1
vote
2answers
68 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
179 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
votes
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 ...
0
votes
0answers
46 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
53 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 ...
1
vote
2answers
115 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
49 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
39 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)?
0
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0answers
40 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 ...