Questions tagged [current]

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

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Battery Charger and Load Current

I'd like to use this Battery Charger. I need to charge a 4.2V Lipo battery and this charger IC can also power the system load simultaneously. I've two questions. This battery charger IC (from the OUT ...
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Finding IC for use in V/I converter [closed]

I'm trying to find an IC for use in my master thesis project. The IC I need must have these specs: Input is voltage (-5 to 5 V) Output is current (less than 10 mA, like -5mA to 5mA)
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Torque to FOC Iq current conversion

I am controlling the quadrature current (Iq) of this BLDC using the TMC4671 FOC controller. The FOC control seems to work fine, but the end goal is to control the real torque produced by the motor. I ...
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Output current/voltage for PIC12F675

I want to get some clarification about output current and output voltage from a PIC12F675. As I read in datasheet, max. current for an output pin is 25 mA. Is it always 25 mA, or will it depend in ...
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How to implement TYPE_C VBUS status LED?

On my custom PCB I have a type-C connector with PD option. I want a visual indication on my board when someone has plugged a cable in. I was thinking of connecting an LED to the VBUS pins in the type-...
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Working of this protection circuit battery

I'm going through this application note - because it is said that the MCP73833 device does not allow to charge the battery and drive the load simultaneously. Hence, they've given the below circuit in ...
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Understanding the function of Boost capacitor

I'm going through this MOSFET Driver IC - MIC5021. Since this is a high side switch, the gate voltage should be higher than the source voltage, which would be the Source voltage, Vdd. According to the ...
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Question regarding MOSFET driver

I'm going through the datasheet of this MOSFET driver IC - MIC5021 to understand the pins and the terms better. In the first page, it is mentioned as, The MIC5021 high-side MOSFET driver is designed ...
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What is the name of this specific method used to solve for the step response of a circuit?

I'm entering the third year of a degree in Electrical Engineering and we're just now getting to the step/transient response of circuits. My professor is enamored with a particular method for solving ...
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My IRL540N is smoking

I am using an IRL540N MOSFET to drive a 12 V pump (about 6 A) and a 12 V solenoid valve (about 1 A max). It's smoking after just two uses. I need to know two things. Is it still alright? It's still ...
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Understanding battery charger terminology

I've a few questions regarding this charge management controller IC. On page 11, section 3.0, they mention Charge Status Outputs (STAT1, STAT2) and Timer Enable and in section 4.3, page 14, they ...
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Why are my transistors failing?

I'm trying to make this supposedly simple motor controller. Here's a brief history of past events, though I'm not sure they're related to what I'm facing now. I've built the schematic half on ...
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Choosing a resistor value for a microcontroller controlling multiple LEDs

I have circuit controlled by a PIC16f18076 microcontroller that simply powers and turns on some LEDs. I am having a lot of difficulty figuring out how I can prevent my circuit from frying any of my ...
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How to find the input injection current of this device? [duplicate]

In this device, no information is given regarding the maximum input injection current. How to find the maximum input injection current from this datasheet? I'd like to know the current for the device'...
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How to check current rating of an adapter? [duplicate]

I have this old adapter, which I checked through multimeter shows 12 V. I need to power up the circuit with a power rating of 12 V and 2 A. Is there a way to check the current rating of this adapter?...
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Difference between Safe Operating Area (SOA) of two MOSFETs

I want to compare the Safe Operating Areas of two MOSFETs based on the graphs given by the manufacturers in the datasheets. Our application is a 24 V inverter. What I concluded based on the ...
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Is it possible to limit circuit and protect to 5 V whilst having a 5 V USB power in? I need around 1A current

I have a USB-powered circuit and would like to limit the voltage to 5 V for overvoltage protection. I also require around 1 A for potential current draw. Is this possible? Most solutions I find have ...
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12 V vehicle power distribution question

I am trying to find a solution where I need to add a connection to power a device that is expected to draw 50 A. The car has a DC-DC converter which has a current limit of 160 A which is also used to ...
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Protection current

How to find the maximum injection current that the internal (clamping) diode can withstand? It is not mentioned in this datasheet
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Why is the current through the DIAC in the given circuit very low and how can I increase the current through the diode? [closed]

[![circuit to trigger triac using diac][1]][1] Why, even though the voltage accross the DIAC is enough for it to go to the conducting state, is the current through it too low to trigger the TRIAC? How ...
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How much soil does it take to make a viable earth ground?

My device lives in the soil, in a flower pot, or other garden container. It is about 16" long, has a 40-50mm diameter and runs on 5VDC. My question, how much soil does it take to develop a viable ...
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1 answer
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Current source circuit components

I want to make a constant current driver for a laser diode (500 mA max.) based on the circuit shown below: Here is my version: In my case D2 and D3 represent the laser diode. There is a NC relay and ...
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How can I boost the output current of this pulse generator (LF353, supplied with ±15 V) to above 25 mA?

I have a pulse generator design. Everything works fine, but it is required that the output current is above 25 mA. (The 9.69 kΩ is just a variable resistance to modify the output frequency.) ...
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What is the maximum output current for this op-amp (OPA4227)?

Usually in an op-amp datasheet I see that the op-amp output current's min, max, and typical values are stated. But for the OPA4227 op-amp one finds two sections about currents: Signal input terminals ...
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Current flow through the diode in the picture below

Power Electronics by Ned Mohan, Chapter 5 In Fig 5-3 (b), how can there be a current i in the circuit when source voltage Vs becomes neagtive? Wouldn't the diode be reverse biased?
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Trying to understand a phase shift oscillator diagram

I can't fully understand this circuit below "Phase Shift Oscillator," especially the part about the three capacitors in the transistor base line and the three resistors. I know that there is ...
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ACS712 active and reactive current

I am planning to use ACS712 5A current sensor in my project an I was wondering if anyone knows if this sensor measures just the Active Current or also the Reactive Current. The datasheet doesn't say ...
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How can an analog multimeter have a combined mV and µA scale?

Looking at analog multimeters on Amazon I came across several that have one switch position that appears combined for the lowest V and µA settings. I've used various analog multimeters over many years ...
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How to find the differential equation of the current i₁?

I am trying to find the differential equation of this circuit: I tried to use KVL at the left mesh which gave me \$E=R\cdot i+V_c\$ From \$V_c\$ I can calculate \$i_1\$, but then I didn't know how to ...
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How to calculate the maximum current a wire can handle?

Is there a formula for calculating the maximum current a wire can conduct without melting? I found one: I = αd^(3/2) in which I = fusing current, d = wire diameter in inches, and α = a constant ...
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Three-phase, 480 V, 200 A supply, 480 V, 30 A load/charger compatible? [closed]

I have a 480 V, 30 A charger for a large JLG/lift. The power cord for the unit says it is only rated for 30 A. Could I still use this unit with my 480 V, 200 A source/disconnect? Would I need a ...
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6 votes
3 answers
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Does the LM317 voltage regulator have a minimum current output of 1.5 A?

The LM317 voltage regulator is supposed to have a minimum current output of 1.5 A. What does that mean? I am only familiar with the idea of a maximum current output. With this minimum current, will ...
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Increasing only current using LM317

For the LM317 there is a precision current regulator circuit. This circuit uses an LM317 and only one resistor between the out and adjust pins. The operation of this circuit completely satisfies me, ...
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USB meter does not detect current in very basic USB circuit

I have a USB LED light (for plants) that draws 5 V @ 1.16 A when I plug it in, as measured by my USB volt/amp meter. EDIT: The problem was caused by the specific USB tester model KWS-MX18L. See answer ...
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Excessive noise in stepper current

I am currently utilizing the TMC5160-BOB module to operate a stepper motor with a current rating of 2.4 amperes via the SPI interface. The supply voltage for this system is 29 volts. I am ...
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Can someone tell me about the current transients that the device can withstand

In this device, VSC8531, I see the information about the transients that the device can handle on page 67, table 5.4. It is for ESD/ lightning transients. I just want to understand about the current ...
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Can LEDs be powered from a power supply instead of batteries without getting too much current?

I'm very used to powering individual LEDs with a battery and I'm not usually concerned about putting too much current into them, however, I worry that using power from an outlet that can do 1 A DC ...
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Open-loop simulation of a voltage-controlled current source

Short summary: V3 decides the current going through R2. If V3 is 0 V then no current is going through R2. If V3 is 10 V, it will be approximately 50 mA. I want to do an open-loop simulation of this ...
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Difference in amperage at the plug vs at the source (three-phase wye, 120 V and 208 V loads)

I'm trying to understand the difference between how my work calculates power at the load vs how we calculate the sum at the source. We run temporary power and plug in several hundred industrial ...
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How to calibrate a shunt with a MM and another shunt

I had noticed someone in my lab calibrated a shunt with a MM and another shunt, was wondering how they went about this? Thank You
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Load current from two lithium-ion parallel cells

How do I calculate the current flowing from V2 into V1? I have two lithium-ion cells that are connected in parallel to a load R3. Let's say R3 draws 200 A. How much current will flow through NODE 1 ...
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How does a wireless charger transmitter detect the power required by the receiver?

The image above shows a 20W phone charger wireless transmitter. The transmitter details stated Charging power: 5W/7.5W/10W/15W/20W automatic identification on its receiver coil) How does the ...
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2 answers
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Maximum current through PCB traces

I am currently looking at a layout and I have a trace which has to sustain this current waveform (single pulse) according to the simulation: As you can see, the current is passing through the trace ...
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How does the electric field inside a conductor remain zero?

I'm learning about current in conductors, and came across the statement that "The electric field inside a perfect conductor is zero", this is frequently explained used Gauss´s Law by saying ...
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How was the highlighted value obtained?

I'm currently calculating the excitation current for a transformer but I keep getting the wrong answer. I tried converting the highlighted values to rectangular form (first highlighted value) but ...
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Power cable rating: amps vs. wattage [duplicate]

I have a very weird science experiment, where I need to provide 50 A over a cable. The requirement is independent of voltage (for a Hall-effect sensor). My plan was to use a 5 V, 100 A power supply ...
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Replacing current shunt resistor with different value. Is there a problem?

I have Nitecore UM2 (2 slot) battery charger whose current sense/shunt resistor of 0.1 ohms R100 (package 1206) blown. I replaced with working slot to see if everything works good and it is. I am ...
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Is Ohm's law really accurate?

Say I had a component with a resistance of 100 Ω, and I attached a 12 V power supply across its terminals using: a thin wire a thick wire Would the component in both cases really draw (12 V/100 Ω) A?...
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How to stabilize an op-amp with a MOSFET in the feedback loop

I am modifying a current source/sink and there are three circuits that are relevant which are shown below, all using a MOSFET and an op-amp to stabilize a voltage across a sense resistor. My questions ...
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What does the usable range depend on in this current sink circuit?

I'm trying to build a controllable constant current sink circuit. I have found a circuit that I liked and tried a simulation. I wanted to get 0-20mA of current using a 0-2V control signal. Everything ...

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