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

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2
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1answer
81 views

Measuring Remaining Battery Life

I am working on a project testing alkaline batteries and need a way to quickly measure remaining battery life. I would like to be able to estimate mA-h remaining in the battery. If I measure mA-h over ...
1
vote
1answer
78 views

Is this current measurement solution okay?

One wishes to measure the RMS current (12A max.) drawn by an AC motor using a PIC16F887 at intervals of 1 second. One cost effective solution I am considering is using a current transformer, a bridge ...
0
votes
1answer
42 views

Can an amplifier deliver a higher power for a short burst as opposed to continuously using the same circuit

I am struggling to understand the fundamental power requirements for an amplifier. If I want to deliver 56 V rms to a 7.5 Ohm load I can use P = V^2/R and find that I need 418 W rms. Requiring a ...
1
vote
3answers
77 views

Paralleling power supplies for higher current

I am looking at using two Cincon (CFM80S240 and CFM60S240) power supplies in parallel to achieve a higher current output. Is this possible? If so, can I just hook them up in parallel, or is there some ...
2
votes
0answers
99 views

Current capacity of copper wires in vacuum

I’d like to know the current carrying capacity of copper wires in vacuum. The current plan (NPI) calls for sending ~3 amps through the vacuum space of a cryostat. Has anyone done this? Have any ...
0
votes
1answer
119 views

Current draw at digital output pin differences in two equally coded segments -probable cause?

I measured the current output of an Arduino Duemilanove (with an ATmega168) in two cases and found out that the currents differ strongly. The following code creates an output of 72mA at pin 13 ...
0
votes
3answers
90 views

Voltage decreases on higher current

I have a circuit composed of Arduino Mini Pro 3.3V and GY-GPS6MV2 (GPS Ublox NEO-6M). I have tried to power it with 3 different sources: 3xAA NiMH in serie connected to RAW pin of Arduino and using ...
9
votes
6answers
3k views

How is the internet able to transmit data so fast?

I'm not sure if I'm in the right place or not, but I figured someone here could maybe provide a good answer. I want to know how electricity is able to flow so fast. For example videos games nowadays, ...
10
votes
4answers
850 views

SCR in this circuit exploded - why?

Some of our boards have a damaged SCR. I just witnessed one in person today. The SCR actually exploded upon power-on. A part of its packaging material just flew off along with an exploding sound. ...
1
vote
1answer
53 views

How many inputs can a single mcu output drive?

I am planning a project that will have many ATTiny chips connected together. The idea is that a master node will send various control signals that every slave node will listen to. My system could ...
0
votes
2answers
95 views

Power Supply Current is very low

I made a power supply from a diy site, the schematics are above. The site showed the project as 2amps output but I'm not getting even close to that. I'm getting around .14A or less. Does anyone know ...
0
votes
3answers
58 views

Current pulse detection circuit

I'm trying to recover a signal that is encoded and then modulated as 1mA current load pulses on the supply line. What's the best way to do this? 250us long 1mA current increase on each edge of ...
0
votes
1answer
59 views

2N7002 Continuous drain current?

I'm currently looking for some MOSFET's to do some RGB LED lighting with using PWM. I found the 2N7002 in SOT-23 packaging (datasheet). According to the datasheet the MOSFET can handle a continuous ...
-1
votes
4answers
74 views

30A power connector

I've never really used power connectors before. I am working on a project and saw there are power connectors in it. We had some issues and changed the manufactured power connector to a 30A power ...
0
votes
1answer
41 views

Strobe light failiure detection

I am trying to make an alarm system (audible and visual) using a siren and 3 strobe lights. I am using 12v battery like the one used in cars. Now I would like to detect when any of the alarms have ...
-2
votes
2answers
58 views

What is current forward (if) of an IR LED

I see a lot current forward on datasheet, but I don´t know the difference from the "normal" current. EDIT On this datasheet, I saw a If (current forward) of 100mA and then on page 3 it states about ...
0
votes
0answers
35 views

Buck converter effect on amp draw

It was my understanding that the circuit will only draw the current thats needed - a 1A servo will only draw 1A. I have a rather large project so I am using a 24V 5A rated wall adapter, and using ...
1
vote
2answers
116 views

PCB Track Width for High Current

Let's say I need a 20mm wide trace in 1oz copper to handle some high current. Could I just have a 10mm trace on one side and another on the other side, connected by a plated hole to handle the same ...
1
vote
6answers
166 views

Why do cables and batteries have a positive and a negative side?

I am a beginner in electronics, mostly self-taught. If electrons are negatively charged and are the reason for electric current why is there a 'positive' side on a battery and negative one? Don't ...
0
votes
0answers
51 views

Inducing Eddy current in wet clothes

Is it possible to induce eddy current in wet clothes and dry them using the resistance heat generated? I don't want to connect any wires to the clothes.
1
vote
1answer
49 views

Current source for boost converter

I'm designing a boost converter to boost 3.3 V to ~25-30 V. I have successfully simulated it in SPICE, but the current draw for converter is enormous - about 8-9 A. How can I handle this nuisance? ...
0
votes
1answer
35 views

how to read current from sense pins of UWS-5/10-Q48 muRata chip with arduino

I have a muRata UWS-5/10-Q48 DC-DC converter chip which has sense pins and I hope to read the current draw of the load which is connected to the arduino and print out the current draw. I am not sure ...
0
votes
1answer
60 views

Current transformer saturation

I have a current transformer from this page. I tried to measure the secondary voltage Vs when I apply Vp=230 V and I change the Ip, like this: But at some point the voltage Vs is not changing ...
1
vote
1answer
142 views

How much current can Solderless Breadboards handle?

I'm working on a project with a few stepper motors. I want to breadboard them so I know the circuit works well before creating a physical PCB. Each of the three motors is rated 2A, but I'll be ...
0
votes
1answer
17 views

Displacement current generation in dielectric and in vacuum? How is it different?

I understand how the displacement current work in dielectric such as in parallel plate capacitors but don't know how they would work in a vacuum where there is no dielectric present. Can someone ...
1
vote
2answers
72 views

How do phones charge their battery at seemingly any rate with no issues? 500mA or 1A or 1.2A depending on the charger?

If most use some sort of li-ion battery, and those batteries like to be charged in CCCV format how can my phone charge just fine at 5V, 500mA or 5V, 1A or 5V, 1.2A just fine (actual current delivered, ...
0
votes
6answers
76 views

How do I figure out the exact voltage and current needed for a part?

Whenever I look for parts in my local electronics store, I come across parts(e.g a speaker), that have just a power rating stated(e.g 2W). While I know how to calculate power,voltage, resistance etc, ...
0
votes
2answers
62 views

What influences capacitor maximum current handling?

In this answer it is said that the maximum capacitor current handling is "largely a mater of losses", what I can understand that is a factor for maximum dissipation. So, what is the thermal ...
1
vote
1answer
42 views

Finding the Current in a Series RLC Circuit

Question : If the input to an RLC serise circuit is \$V=V_{in}\cos(wt)\$, what is the current I in the circuit in terms of \$V_{in}, w, t,R,L,C,\theta\$? Answer : $$I = ...
0
votes
1answer
70 views

Constant current LED driver min / max current rating explanation

I currently have a 150-1500mA led driver that I sue to power a 30W LED. Driver has adjustable maximum current pins that I can use to change to match the maximum current. I have it set to 1050mA. I am ...
0
votes
1answer
32 views

Current of a circuit with regulator

When the specification of a regulator says that output is 1A for example the whole current of the circuit will be 1A? For example I have a regulator in series with a 100Ω resistor and a 7V source.The ...
1
vote
0answers
87 views

Current through Capacitor, how is it possible? How does it relate to displacement current? [duplicate]

What my professor is telling us that there is no conduction current through a parallel plate capacitor but the current that is passing through capacitor is the displacement current and this phenomena ...
0
votes
0answers
35 views

DIY Power bank for router? [duplicate]

I'm an electronics enthusiast living in a country with a lot of power cuts, especially through the summer. I want to build a 9V <1A DC power bank for my internet router running on a AC->DC power ...
0
votes
1answer
29 views

Finding the Current I1 using Polar Notation

For the circuit in Figure Q3. Convert all voltages and currents to the form X sin(t + φ ). You need only find the stead-state solutions. Solution My Steps ... It seems that I am going along ...
2
votes
2answers
111 views

What actually happens in a RC circuit?

I'm currently working my way through a beginner's electronics book(electronics for dummies) where i am introduced to RC circuits as shown in the schematic below. simulate this circuit – ...
2
votes
1answer
124 views

How exactly does a capacitor discharge its charge?

When an empty (discharged) capacitor is connected to a battery, it slowly charges up as one plate fills up with electrons, while the other plate has electrons drawn away from it towards the positive ...
3
votes
4answers
245 views

How exactly does a series voltage divider work?

I apologize if this comes down to a lack of fundamental understanding of electrical flow, which it probably does. When I look at this: I don't understand why Z2 is factored into Vout - as far as I ...
0
votes
2answers
80 views

Convert DC generator to variable AC

Is there a way to convert a DC generator signal to AC and be able to control the frequency and current? Ultimately, I would like to use this signal to measure the impedance of a battery.
1
vote
1answer
42 views

How to monitor produced energy?

I want to monitor energy produced by 250W solar panel. But I need some hints. Does anyone knows something? Is it possible using ACS758 chip or better I have to use current transformator? Finally I ...
2
votes
1answer
41 views

Amount of output current needed by voltage regulator?

I am trying to choose a voltage regulator. One of the metrics I keep seeing is output current, e.g. "Output current up to 800 mA". Does that mean the sum of current that the rest of my circuit ...
3
votes
1answer
58 views

Higher current output from transformer?

I just received a battery charger in the mail, but I forgot to purchase the power supply. I was wondering if it was possible to use a transformer from an old lamp to supply the charger instead: The ...
-1
votes
1answer
75 views

Back EMF and Source EMF, stabilizing current?

In a circuit where there is change in a magnetic flux, Back EMF is induced. When back EMF is increases it reduces the source EMF( or oppose it) and therefore, the current is reduced, in order to ...
0
votes
3answers
83 views

Maximum current for a single-core cable?

I want to connect the cables of a LiPo 7.4 V 2200 mAh battery, to a breadboard. However, the only way to make this happens is to solder the ends of the battery cables with a single-core cable with ...
0
votes
1answer
102 views

220V AC power cable max current

I installed 1mm2 copper AC power cable across house for video surveillance (8 cameras, Power Consumption for each camera is Max 4W, 12V). For each camera has its own 220V->12V converter rated 3A. ...
2
votes
1answer
214 views

Reducing Undershoot and Overshoot in a custom voltage regulator?

I'm trying to build a voltage regulator that takes in a reference voltage and an unregulated voltage (to power the components, and this voltage is always greater than the reference voltage) and ...
2
votes
2answers
68 views

Why does the “top” transistor in a cascode not set the current?

This has been bothering me for some time. Why is it that the overdrive voltage of the bottom transistor in a cascode controls the DC current, and not the Vgs of the top transistor? Similarly, in an ...
2
votes
2answers
428 views

What is CV & CC in power supplies?

In many power supplies, there's CV & CC indicators. What does they mean?
0
votes
1answer
204 views

How to calculate the resistance of a complicated circuit?

I learned in high school the basic rules of how to compute resistance between two points, given a network of resistors. You try to rearrange the circuit so into parallel parts and series parts, then ...
1
vote
3answers
128 views

Simple high-side current change to digital output

I am trying to read OUTPUT 1 and OUTPUT 2 to digital pins with pull-down resistors on a micro controller but they will always read HIGH. How would you detect the change in current so that when SW1 is ...
0
votes
0answers
47 views

Drawing 2A from 1.5A source. What are the risks? [duplicate]

I have 220V to 12V converter with 1.5A output. My simple motor draws 12V and 2A. Are there any potential risks, when the difference is so small (besides motor being slower)? I cant figure out if ...