Questions tagged [current]

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

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How does the current drawn from a battery change when it is stepped down using a regulator?

I'm wondering what happens to the current when the voltage is stepped down using a regulator. here is the situation: I have a load which draws about 500mA at 3.3 volts, and I would like to regulate ...
85 views

Does Negligible Current Continuosly Leak into the Air from an Outlet?

Pursuing my goal to learn more about electricity, I stumbled upon this idea. As I've learned, a current will travel from a high voltage source to a low voltage destination. Since there's air between a ...
54 views

How does the current get distributed in a Serial-Parallel battery pack?

I was following a tutorial that tries to emulate the voltage drop in a battery pack with cells in parallel and series (in a 6s2p connection). The pack looks like this: Let's say that one applies 20A ...
73 views

Power bank's output current

I'm wondering what factor determines the maximum output current of a power bank. Is it limited by the internal battery's current or the output current of the voltage regulator? Also I'm not sure that ...
57 views

Current calculation dependant on Mbed PWM voltage

I'm looking at this question in a design exercise. By simple calculation the voltage is 9V, the impedance of the heater is 3ohms. So the current through R is 3A? OR Do I need to take into account the ...
74 views

Slew rate in a transmission line

Let's say I have a 3km long transmission line with a capacitance of C = 50pF/m, the resistance is 100Ohm. The inductance and the conductance per unit length are negligible. If I want to receive the ...
470 views

Energy of capacitor

Hi readers, since energy stored in capacitor is given by the above formula. Does it mean if i use a voltage multiplier connected to capacitor, it will help to increase the maximum amount of energy ...
185 views

Can I die from touching one capacitor lead?

Suppose I have a charged capacitor and I only touch one of the plates or leads. Will current start flowing through my body? I think yes, because there is an electric field between one plate and Earth/...
138 views

Can a 100W heating element heat up just as fast as a 300W heating element?

Say I have a 100W and 300W heating element that are both drawing 5A of current. The 100W heating element has an applied voltage of 20V, and the 300W heating element has an applied voltage of 60V. ...
75 views

Shunt current measurement on phase

I measure the current of two phases (directly phase current, not the low side MOSFET current) of a PMSM motor and on some hardwares (2 of 10) I have issues with the phase current measurements. As a ...
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Minimize the current spike

I have simulated a H-bridge PWM temperature controller for Peltier module. To smooth the PWM output I have added a LC low pass filter, the cutoff frequency of the low pass filter is 734 Hz. I am ...
90 views

4 to 20mA interface technologies [closed]

I'm researching solutions for reading the interface. 4 to 20 mA. Today I only know the ADS1115 schematic solution below: What are the solutions for reading this interface in a professional and ...
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How to calculate the discharged current of a capacitor from the discharge curve?

I observed the discharge of a capacitor on an energy harvester chip via an oscilloscope. The Output was used to power a BLE module. I know the capacitor value, discharge time, and the top and bottom ...
29 views

How to calculate current value for DOUT and RIN pin in MAX3221E texas IC?

Hi Im going to use ferrite bead in the Dout and Rin pin in MAX3221E IC of Texas. How to determine current rating of the pins , thereby i can choose the current rating of ferrite bead??
151 views

How can I find the current in this BJT & op-amp circuit?

I have a background in EE but am very rusty. I was given this as a problem to help me brush up on my skills. I'm supposed to solve for I3. What I've come up with so far is that the positive terminal ...
184 views

Why is this "fading" as if the current draw is too high?

I am attempting to build a "dice game" based upon an Arduino Uno. There will be 5 dice represented by LEDs. To manage the number of LEDs (7 for each die + 1 for an indicator) I have elected -...
54 views

Short circuited power supply still safe to use? [closed]

Last night I short-circuited a Samsung 5v 1A phone charger to see how much current it could deliver. With my multimeter I measured 1.2A, despite the fact it says 1A. Is it possible I have damaged my ...
39 views

Capacitor value on supply grid

I am using ATmega328p TQFP for application described in schematic. simulate this circuit – Schematic created using CircuitLab So there is plenty of load on output side (up to 500mA). I have ...
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Can I connect a 1A device to a USB 3 port?

All, If I were to connect 16 WS2182b LEDs in series (16*0.06=0.96A) and an Arduino to a USB 3 port on my PC (0.9A max I think), would my PC/USB controller get fried or would the LEDs just run dimmer? ...
143 views

What is the best and compact method for varying AC current between 1mA to 100mA for a 500VAC?

I am working on a testing project. The objective is to test an equipment which assures safety to personal when there is a certain current passing through earth wire. So, I must emulate an unsafe ...
136 views

Would ground fault cause breaker to trip if neutral not bonded to ground in main panel?

Suppose normal residential main breaker panel (not subpanel) is wired correctly except the neutral bar is not bonded to ground. Assume a 15A breaker in the panel powers an exterior light with a metal ...
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What effect in the current will have the change of the diameter of coil but same length of coil and same magnetic flux?

First image is one coil with the large diameter and a magnet rotating to create current in the coil. Second image is the same set but the diameter of coil is smaller.
63 views

Max a current tolerance of led strip and microcontroller

I am trying to hookup a led strip to a 5 V 40 A power supply and ESP8266 microcontroller. I know that the led strip and microcontroller can only draw as many amps as needed. I am concerned about the ...
59 views

AC to DC power calculations? [closed]

I have an ac to dc power supply and it measures at 244.0Vac on the primary side and the secondary side it is reading 21.34Vdc. I attached a load to the secondary side that is drawing 0.390amps and ...
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Can the electric pulse replace the mud pulse in logging during drilling signal transmission?

For LWD signal transmission, because the speed of mud pulse is too low to be compared with the speed of electrical signal in metal drill pipe, can wide pulse electrical current signal be transmitted ...
110 views

MOSFET current spike - Push-pull converter

I am simulating a 150W push-pull converter in LTSpice as shown below: I'm viewing the waveforms after 200mS which I believe is giving stabilized readings. I'm seeing huge current spikes on the drains ...
1k views

Getting the energy consumption in joules over a period when having current and voltage

I'm trying to calculate the energy consumption over a period of 1.3 seconds in joules (J). I have a sample every 100 ms (0.1 second) with the current and voltage (in volts) (in practice, the samples ...
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How can I determine the direction of current and how many different currents there are?

Whenever there are circuits with many batteries in parallel I get confused and I don't k now the direction of each current or whether it's the same current flowing or another.
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why current doesn't flow from separate +&- batteries

It might sound simple but I'm new to electronics. If I connect 2 batteries in series and the voltage adds up then why doesn't the current flow from -&+ of separate batteries. I mean, why do I need ...
41 views

Any experience with Current Sensor TLI4971

I'm looking to include current overload protection for a new application and wondering if anybody has experience with Infineon's range of TLI4971 devices. Datasheet here I like the fast over-current ...
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Is there a way to dim CCFL lamps in a monitor backlight?

I use 30 inch monitor Samsung 305t that uses 16 CCFL lamps as a direct backlight. The driver consists of 8 HV transformers, each of them running 2 lamps in series. Some info about the lamps: As you ...
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Near field probing technique

I am reading about the near field probing using Electric field probes and Magnetic field probes. I understand that E field probes would pickup voltage changes and the H field probes would pick up ...
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Can I create my own good reading in µA?

This multimeter is in between a Rpi0 3.3V pin and a BME280 sensor VCC. Most of the time the sensor is sleeping. You can see on the picture, the reading is 620µA, which seems high. Now if I use the ...
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Near field and far field EMI

I was reading this article on EMI near field vs far field. I am confused on how the Electric field and Magnetic field are separate within the near field and suddenly after a certain distance, these ...
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Calculate mAh from logged current samples

I have designed a system that spends most of it's time in sleep and then wakes up to accomplish a very short task so it can return to sleep. Using a CurrentRanger, I have logged the current ...
182 views

What is the maximum current that the Max10 FPGA would require?

I am currently working on a project where I use an FPGA Max10 from Intel. Is there any approximate value of what the maximum current is, that the FPGA Max10 requires? I know that this highly depends ...
52 views

Using more pins on connector to satisfy current ratings

I have a power brick that is rated at 20v and 12a. I will need connector between two wires, but I as unable to find one that is either not ugly, to much bulky and has a lock system. I thought to use ...
160 views

Current characteristics of ISO7421 isolator IC

I am using an ISO7421 IC for serial communication isolation. I have read the datasheet of the ISO7421. I am not able to understand the current characteristics given in the datasheet. My concern is if ...
112 views

Have I understood transistors correctly?

These are what I know and what I've concluded about transistors. Correct me if I'm wrong: It's all about current. When we have a determined voltage differential source, BJTs are used to boost the ...
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2.5V or 3.6V? for TDC application

My application is for Smart Water meter. The TDC-IC I'm using is MAX35103 https://datasheets.maximintegrated.com/en/ds/MAX35103.pdf. My device is battery powered and operating at 2.5V .Which is ...
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Are large currents from my motor killing my Arduino?

In my last question about the circuit below, it was mentioned that the motors can emit large amounts of current at peaks. I am worried that this large amount of current may be the reason I keep ...
61 views

How can this MOSFET steer the current of this LED driver?

I am powering a Charlieplexed LED array with this current source as shown in the first picture attached: One requirement was to be able to control the current so I decided to insert an array of ...
73 views

Dynamo connected to ceiling fan to charge a battery

Just a hypothetical scenario : I am thinking of connecting a dynamo to the ceiling fan to charge up a battery which might be later used to power some low power gadgets. Whether this would save my ...
54 views

connect impedance parallel to 3 phase load

Suppose we have a 3 phase load connected to a 3 phase voltage source and connect a capacitor parallel to one of the phase loads like in the image below. simulate this circuit – Schematic ...
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Response of mosfet in high frequency

I used two mosfets to control current passing through resistance 5ohm, shown in the circuit of the attached file. The simulation results show that the mosfet switching frequency higher than 10KHz ...
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How can I find the VBE of a common-emitter amplifier?

I have a common-emitter circuit as above. I need to find the value of Vbe and IC. The picture below is the equivalent large-DC analysis of the circuit. Applying KVl Ic = (VTH - VBE)/((1/B)RTH+(B+1/B)...
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What will happen to an LED if the forward voltage (Vf) is greater than its supply voltage?

For example, if the supply voltage is 3.3V, and the forward voltage of the LED is 3.5V with a forward current of 20mA, what will happen to the LED? I have already tested the circuit using a 220ohm ...
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MCU could not turn on transistor

I am using atmega328p and PNP transistor FMMT720. Goal is simple to switch on and off transistor with GPIO. For specification part: Datasheet says continuous collector current is 1.5 A and my ...