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

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38 views

How do I detect servo stall with an Arduino?

I am controlling a standard 5-volt servo with an Arduino with PWM. My objective is to rotate the servo until it physically gets stalled (feels resistance) and then stop. Then I want the Arduino to ...
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3answers
45 views

Limiting current draw on a camera battery charger

I have a camera battery charger which is driven from a 12V (measured 12.2) switched mode wall wart rated at 1A. All three items (charger circuit, wall wart and battery) are stock, but all three heat ...
0
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1answer
56 views

How to calculate electric current in this electric circuit?

Ok here is the problem. I have this circuit ( picture below ) and I need to design buck converter for it. I was told by my mentor that I should calculate electric current this circuit will consume. ...
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1answer
35 views

How would I properly develop a current rating for this system…?

I have a system that I have recently developed for in house (manufacturing) equipment testing. Transformers rated for 80VA (264V, .303A) are used in series and rectified using a full-wave diode ...
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2answers
33 views

Can different sources with same voltage output can drive different amount of current through the circuit

I started experimenting with electronic devices. While I was doing that I connected a DC motor to output of arduino which provides 5V. It could not provide enough amount of current. But when I ...
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2answers
51 views

Can output current be higher than what the input source can provide

One basic question.Am controlling a group of LEDs (connected in series and parallel) through a MOSFET switch.The input voltage is provided by a battery @ 5V,2A rating. The total current consumption of ...
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1answer
33 views

how to calculate the frequancy and impulse response of the photodiode-detector

can you help me to do the problem ( some hints how to solve those problems based on experimental method course)
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3answers
68 views

Why does the current waveform become non-linear in a bridge rectifier?

This is my bridge rectifier circuit, and I'm trying to understand why the current waveform of the source deforms the way it does when you approach an ideal capacitor. Source V1 is 9VAC. I simulated ...
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3answers
97 views

Voltage current relationship

I'm studying cert 3 in Electrotechnology as an electrical apprentice. My tafe lecturer is insisting that in an ac circuit, and increase in voltage will cause a decrease in current. I'm aware that it ...
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4answers
104 views

Whats the point in conserving electricity if the AC current produced cannot be stored?

If we cannot save the ac current produced in a battery or some device like the DC current there is no point in conserving it because current once produced should be consumed somehow!! My faculty said ...
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3answers
79 views

How does a constant current (CC) power supply regulate voltage (V) in parallel circuits?

I see that some power supplies provide a wide range of output voltages meanwhile maintaining the current. For example: 2.7 A, 20-36 V output. I understand that the voltage rate will depend on the ...
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1answer
102 views
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1answer
31 views

How to implement a current controlled voltage source, or a comparator that trips once a certain current is reached?

I have current flowing through a CCVS, once 10A is reached, the CCVS puts out 10V, which takes a comparator's output high. The current that goes through the CCVS continuous to the load. Is there a way ...
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0answers
55 views

System design with 5 Halogen lamps [closed]

In a system with 5 halogen lamps that are rated at 120 V, 800 W each. The inrush of these lamps are 1200 W each. You have one 120 V, 20 A powers buss available to you. a. Can all the lamps operate ...
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1answer
29 views

ATX power supply shuts down

I'm working on a power supply for my camera (powershot SX150IS) in order to leave it on for long periods of time. So I took an old power ATX power supply and connected the 3.3V output to the camera, ...
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0answers
34 views

Atx to bench power supply

I am trying to convert an ATX power supply to a bench power supply. I wired all yellow and black wires together. The problem is that at 12 volts I get max 3 amps instead of 18 amps as written on its ...
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3answers
46 views

Why is current going towards the voltage source in this circuit?

You can see that Is was labeled as going towards the voltage source when doing KCL at node a. Can someone tell me why? Is it not supposed to go into the node?
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0answers
12 views

What's the current-vs-bias difference between a conductor and a semiconductor with free charge carriers in its conduction band?

What are the electrical differences between a piece of metal and a piece of a (heavily) doped n-Si? How would the difference in charge carrier concentration affect current flow under low-to-breakdown ...
0
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1answer
34 views

Per coil vs. per phase current

I'm working on a project using this stepper motor it is rated at 1.5 A/Phase current. Initially I planed of using this driver, so I checked if it can provide enough current for the motor. The website ...
1
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1answer
46 views

Increasing the current to a solid-state relay?

I've got two strings of LED Christmas lights that operate at 120 V / 0.04 A (4.8 W). I'd like to connect them to this 5V solid-state relay: Unfortunately, there's one small problem. According to ...
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2answers
75 views

AC vs DC and ELF - extremely low frequency

given : How do static fields differ from time-varying fields ? A static field does not vary over time. A direct current (DC) is an electric current flowing in one direction only. In any ...
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1answer
53 views

Termination resistors in Ethernet in Kilo-Ohms instead of Ohms?

When working with Ethernet, whether copper or optical fiber, why are the termination resistors always in a few ohms and never in kilo-ohms? Example: 49.9R on transmit & receive pair of PHY in ...
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1answer
57 views

How to picture sinusioidal wave in transmission line(electrical circuit in general) ?

I have a friend who keeps asking how does a sine wave flow in transmission line. I've tried explaning him that it is the folw of charges in either directions but he isn't convinced yet . Can somebody ...
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1answer
58 views

Charging phones with lots of current [duplicate]

My question is, what if I want to charge my iphone that uses 5volts via USB, however what if I had a powersupply that could deliver 5volts upto 10amps, if I used this to charge my phone would it ruin ...
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1answer
51 views

Dot convention in Magnetically coupled circuits

The book says that the for loop 2, the KVL is \$-j3 I_{1} + (12+j6)I_{2}=0\$ , but the loop 2 leaves the dot in its coil. Isn't it supposed to be \$-j3I_{1} + (12-j6)I_{2} =0\$ ?
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1answer
95 views

How can I store energy from short pulses of current?

BACKGROUND: I am an intern with a local company. We have a powerful 60 KW Engine that runs throughout the day. We have a two Machineries that are powered off the Engine directly (using clutches and ...
2
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2answers
65 views

What Does Rated Load of a Tactile Switch Mean?

I want to connect a tactile switch to an GPIO pin of MSP430 (which runs on 3.3 volts). The datasheet of the micro-controller says that IO pins can withstand max current of 6mA. The tactile switch I ...
2
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2answers
70 views

Controlling an electric motor through labview without knowing its speed

I'm having a little trouble running my final bachelor experiment. My group and I are to find out what exactly causes extreme high frictional forces when pulling a steel cable through wet sand by ...
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1answer
32 views

Replace a Solar Panel with a charging brick

I have a small solar lamp with a messed up solar panel. Now i want to replace the solar panel with a charging brick in order to charge my lamp. The question is what specification of charging brick ...
6
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2answers
304 views

Does an electrocardiography recorder put current/voltage on its electrodes?

(I do hope my question is not off-topic) Currently learning about ECG recorders (Our 7-months old daughter has to have one during her sleep), I wonder whether this is a pure "passive" measuring ...
2
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1answer
66 views

Determine the maximum load of a power supply

I am trying to upcycle an old bit of tech I had lying about. The main part I am looking to recycle is the power supply however I do not have specs of the power supply itself. I have measured an output ...
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2answers
78 views

Electric current of inductor

I have a homework problem that was solved by our instructor: "Calculate the electric current of the inductor at \$t=0^+\$." He calculated \$1/30\$ but the answer sheet was says \$-1/30\$. Which ...
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1answer
88 views

Current flow in AC vs DC

If a live wire is taken from AC and connected to a bulb, while the other terminal of the bulb is connected to ground, the bulb glows; but if I take the positive terminal of a battery (DC source) ...
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2answers
56 views

Current regulator static analysis

I'm trying to make (and try to learn something better) about a simple current regulator. I need to make a complete static analisys before starting with the frequency one. But I've some thoughts about ...
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0answers
45 views

How to estimate max current draw from an unknown PSU? [closed]

I have a couple of PSU boards from Sony PS2 consoles. They convert 230VAC to 12VDC and would be useful in a couple of my future projects. Unfortunately there's no information how much current they ...
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3answers
294 views

what is this current source

When we connect a resistor to current source a finite amount of current flows through it right? Okay but how is a closed path complete?I mean the current source has infinite resistance(I'm talking ...
0
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2answers
45 views

Constant current power supply and 2 LED - series or parellel?

I have a very limited understanding of how current works in parallel or in series. I am trying to connect a pair of LEDs to a constant current power supply (1200ma) in which the power supply ...
1
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1answer
151 views

What is meant by output Leakage Current?

Is output Leakage Current= Output Current - Input Current? I encountered the term in a datasheet of the L9938 driver.
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2answers
45 views

calculating the input current that can be taken by an Operational amplifier

Is there a way to calculate the input current that can be taken by an Operational amplifier, if we know its input Bias and input offset current?
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2answers
83 views

Transformer core maximum power

so i am an EE undergrad, and i am wondering if and how exactly does a transformer core limit its power capacity. From my understanding, the rated power of a transformer is due to the current carrying ...
2
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1answer
46 views

Standing Wave ratio vs frequency in power transmission lines?

What is the relationship between Voltage Standing Wave Ratio (VSWR) and frequency in context of transmission lines?
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1answer
39 views

Solar cells, current limited by smallest cell?

I've read on a bunch of different sites that: "You also do not want to mix different sized cells together because the current or AMPS of your solar panel will be limited by the smallest cell in the ...
1
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4answers
296 views

what could be the visualization equivalent of the resistors in series?

Why do resistors in series add-up? Is there any visualization equivalent of that? I have in mind electrons as cars driving on the highway, now a resistor could be a narrow spot (R1) where cars are ...
5
votes
3answers
166 views

How to tackle regenerative current in my H-bridge

I am using 2 of the following H-Bridge to control 2 x 24V 350W electric scooter DC motors. The power is from 2 x 12V 12AH SLA batteries in series. EDIT: These are the entire schematic and PCB ...
0
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2answers
68 views

What is max current for goldpin connectors? [closed]

I'm designing a circuit which consists of two blocks on the same PCB. For testing I'd like to have an option of bypassing the second block and connect the first one to the output. The standard ...
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2answers
75 views

Separating the currents [closed]

I got a big problem that I have to put these to motors together like this but they have same working voltage but different currents and that's what makes the second motor doesn't work correctly ...
2
votes
3answers
277 views

Current calculation in circuit

Please show me the steps to calculate current going through R1, R2 and D1 Led (Green color LED), when I tested this circuit through a multimeter it showed as 2.5ma across R1 and R2 but 0ma across D1, ...
0
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1answer
47 views

Minimum limit for current and maximum limit for voltage while calculating power

I have a brushless Motor then i am using in conjunction with a ESC, powered by a Lithium Polymer Battery(3S 1300mah). I just got a new Lithium Polymer battery (6S 15000mah) from a friend and am ...
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2answers
102 views

How can I work out if a cable can take a momentary current spike?

In this video here, almost 1000A is being run through a 10mm steel bar, and after a minute or so, it melts. https://www.youtube.com/watch?v=YzZ3aJqmT-M So in terms of charge, 60,000C applied for 1 ...
1
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3answers
188 views

Why can't different current sources connect in series?

I've posted different question similar to this, yet still struggling to understand the theory. So here is another attempt to understand as to way two power sources(with different currents) connected ...