Podcast #128: We chat with Kent C Dodds about why he loves React and discuss what life was like in the dark days before Git. Listen now.

Questions tagged [current]

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

Filter by
Sorted by
Tagged with
0
votes
1answer
46 views

Minimum Current for Zener to Clamp Vgs of Mosfet?

simulate this circuit – Schematic created using CircuitLab When it comes to zener diodes I find it hard to get information about minimal currents needed for it to breakdown so I thought I would ...
1
vote
1answer
43 views

Question about feedback in a current reference

I'm studying the following Vbe-based current reference: The author of my book says: Observe that the circuit has two feedback paths around the gain stage. One positive, the other negative. ...
0
votes
0answers
33 views

Question about current reference

I'm studying this thermal-voltage-based current reference: The working principle is simple: M1 and M2 form a current mirror which generates two equal currents I1 and I2 (assuming M1 and M2 equal). M4 ...
0
votes
1answer
65 views

Current Source Biasing with Diode Load

I am trying to replicate a circuit I found in the Art of Electronics (3rd Ed, page 229) but I am having issues. My load is a LED (Vf=~2.5V) and using a BC237 as the PNP (measured Vbe=~.675V). Using R=...
0
votes
1answer
24 views

Current on each winding of a solenoid and wire selection

While I was reading an article about inductors and air core solenoids in general, I came across the term voltage per turn. Until then I thought that all of the windings of a coil are a continuous wire ...
0
votes
1answer
42 views

Is that any best way to measure High side mosfet drain current?

To be specific, I am using 6 MosFETs (for ex. PSMN030-60YS) to drive an inductive load. I want to measure drain current of High-Side MosFETs. The way I am doing right now is by lifting the MosFET ...
0
votes
1answer
44 views

Polarity of the voltage drop on inductance

We know from the Lenz's law that the induced voltage on an inductance has the polarity that determines an oppisition to the variation that has generated it. But in circuit theory the inductance is ...
2
votes
1answer
68 views

Self Biased Current Reference

I'm studying this circuit: The author of my book says that the purpose of this circuit, called "Self Biased Current Reference", is to generate a current almost independently of the supply voltage. He ...
3
votes
5answers
674 views

Why is it not possible to create electricity by forcibly putting electrons into the system and closing the loop?

Why is it not possible to make a device operate by forcibly putting electrons into the system, closing the loop, and having electron repulsion do the job of making charge flow? Making electrons flow ...
0
votes
2answers
78 views

Is the direction of an electric field opposite to the direction of a current?

I consider electricity to be an observation of the property of electron mobility. If electrons go the opposite way of the electric field, what is the connection between the electric field and an ...
0
votes
2answers
96 views

Increasing output current of DAC

I have an application where my Arduino is controlling a mcp4725 DAC for a design replacing a sensor on an old car. The DAC provides the analog output voltage, .25V to 4.9V to the computer. I recently ...
0
votes
0answers
30 views

Charging a device with a power bank [duplicate]

So my device has an input of 5V 0.7A, but the cable isn't detachable from the plug so I need to use a different USB to micro-USB cable. My power bank can output on 2 ports, DC 5V 1A and 5V 2.4A If I ...
0
votes
2answers
72 views

Electric current in mic

For a typical mic a singer uses in a concert, how much current is generated when the singer sings? The current transmitted from the diaphragm into the wire. What does the following specification tell ...
4
votes
2answers
68 views

Current Mirror Gain 1.5 with discrete components

I was trying to simulate the circuit mentioned in https://wiki.analog.com/university/courses/electronics/text/chapter-11 under paragraph 11.4.1. I need to make a current amplifier with a current gain ...
0
votes
3answers
58 views

current drawn by led increase with more leds you put in parallel??against V=IR?

current drawn by led increase with more leds you put which i saw in a video about thyristor ,but more leds means more resistance which means lesser current which is not true as per the video(https://...
13
votes
2answers
2k views

What is wrong about this application of Kirchhoffs Current Law?

At a recent exam I had this very simple problem concerning Kirchhoffs Laws: I am concerned with problem c Now my understanding of this is: I can combine both nodes, and since all currents in the ...
43
votes
2answers
6k views

Why don't electrons take the shorter path in coils?

Below is a copper coil, presumably forming an electromagnet. From my understanding the electrons travel around the coil to produce a magnetic field. But why don't the electrons jump the wires and take ...
0
votes
1answer
71 views

Water as a conductor and bubbles

I tried putting two extremities of a 6 volts battery into water. With salty water, bubbles appear close to the positive end. With unsalted water, what looks like a thin white foam starts to squirt ...
0
votes
2answers
47 views

What is the value of the opposing voltage created by the inductor?

Assume I've connected an inductor to a DC or AC source. The voltage across the inductor due to the source current would be L di/dt. But we know that the inductor induces/creates a voltage to oppose ...
0
votes
1answer
74 views

Why MOSFETs in Battery Management System are connected to negative terminal?

I have seen that the MOSFETs and current shunt resistors are connected to the negative terminals of the battery or the BMS. Is there any specific reason for this? Why aren't they connected to the ...
0
votes
3answers
137 views

Parallel Capacitors with different voltages

Let's consider a capacitor precharged to 5V. Now immagine to put it in parallel with a capacitor which has no charge. What does it happen? They reach a voltage in the middle? Does it depend on their ...
0
votes
2answers
76 views

Where does the sum current of the three currents flow?

In the following star and delta connections, if each individual current enters via Phases R, Y and B, where does the sum of the three currents (that is Ia+Ib+Ic) flow after meeting at the common point ...
0
votes
2answers
69 views

Coil Voltage Rating of Relay

I have seen many relays with same current and voltage rating (like 10A 230VAC or 5A 30V ) but the coil rating (I am not sure, I am using the right word) are different. Some are 5V some are 12V and so ...
0
votes
2answers
65 views

Can a trim-pot wiper or contact point gets oxidized over time?

Can a trim-pot wiper or contact point gets oxidized over time? For example when a potential (high) current is flowing and the contact point of the wiper on the resistive element heats up a little. I ...
2
votes
3answers
119 views

What does “DC Current VCC and GND Pins” in ATmega8 datasheet mean?

I'm using for some DIY project ATmega8-16PU, during the reading of the datasheet (Datasheet Revision 2486AA–AVR–02/2013 ) I've encountered in section "Electrical Characteristics – TA = -40°C to 85°...
0
votes
1answer
119 views

Relays drawing too much current?

I have a problem with my circuit. It's an audio mixer with a PFL module - I've decided to send pre-fade signals via relays. The transformer in +/- power supply is rated 400 mA for each rail. There ...
-1
votes
2answers
122 views

For power loss, P=I^2R, why can't I use I=V/R to find I and put it into P=I^2R [closed]

To calculate power loss using P=I^2R, we cannot use I=V/R, to find current and plug it into P=I^2R, instead we must use P=IV to find current, is there a reason why?
0
votes
3answers
94 views

What is v in p=IV if I want to use p=IV to calculate power loss

I know that we generally use p=I^2R to calculate power loss and if we want to use p=V^2/R, the v is voltage drop. Is it true that the v in p=IV, when calculating power loss is also voltage drop? ...
1
vote
3answers
99 views

If energy is drained from a capacitor linearly, does capacitor voltage decrease linearly as well?

If a charged capacitor is connected to a current source and resistor as shown above, the resistor is constantly consuming 0.001J/s. If you were to make an energy-time graph of the capacitor, you would ...
0
votes
1answer
59 views

Determine total current in a darlington transistor

I'm trying to figure out what will be the total current consumption of a TIP120. Looking at the internal schematic I see that the second BJT's base is following the emitter of the first one so it ...
7
votes
2answers
387 views

How does current flow in this path when all points are at the same potential?

If the potentials at points A,B,C .. etc are at the same potential as the battery wrt the ground, how does current flow then? I'm lacking something fundamentally so it would be helpful if someone ...
1
vote
0answers
37 views

LTC3112 undefined behaviour when power supply reaches current limit

I am getting a behaviour of LTC3112 that I do not understand. I am using it very close to the schematic recommendations in the datasheet. It works perfectly fine until my power supply (TOE 7610-60) ...
1
vote
2answers
71 views

Current flowing in an open circuit to make it the same voltage

I've tried to research this answer for quite some time but i'm struggling to find a proper answer. I think my question falls between antenna theory and batteries. So in a dipole antenna we supply a ...
0
votes
1answer
107 views

How do I use a switch without current running through it?

So there have been plenty of occasions where I would like to use a switch or even potentiometer in simple circuits I make (just little at home hobbyist creations). But alot of the switches I try to ...
0
votes
2answers
104 views

Parallel Incandescent Bulbs and Resistors

I have built the circuit in LEDs and high currents and it works well - when the switch is open, the incandescent lamp lights up but the LED doesn't. When the switch is closed, the lamp goes out and ...
1
vote
3answers
52 views

Need help in cable temperature calculations

I am trying to calculate how hot will a 0.6m long 28AWG wire carrying a load of 12VDC, 0.2A get. I understand that are other factors such as environment cooling rate, thermal resistance between air ...
1
vote
1answer
81 views

current versus voltage supply

I have a power supply that is rated rated: Input: 100v-200v Output: 900 ma (constant) DC 6v-10v https://www.amazon.com/gp/product/B01N9UXZ4C I want to power a single 10Watt LED module, Input ...
0
votes
1answer
80 views

If I increase the number of motors in a parallel circuit, will my current increase? [closed]

I am new to electronics, and am looking to build my own quadcopter. Before I purchase anything, I want to make sure I can get an appropriate battery to power the motors. The battery I am looking at ...
0
votes
0answers
27 views

S-Domain Current Equation for Natural Response of LC Circuit

Problem Statement: In the following circuit, in the initial condition, K is closed and a steady state is reached. At t=0, the switch is opened. What is the current through the inductor? What I Think ...
0
votes
2answers
69 views

How to measure the current in different brands of alkaline batteries?

I need to measure the current in different brands of alkaline batteries - 1.5v AA and AAA, as well as 9v (6F22) - using a multimeter, and a resistor as load. How much resistance must the resistor have ...
0
votes
1answer
87 views

CPU fan connected to solar panel will run but wont start

I'm trying to run a 12V 0.09A CPU fan directly off a 5W solar panel (not ideal, I know). The panel runs the fan fine, even in morning and evening sun. However, the fan will not restart without a push ...
3
votes
2answers
563 views

Potentiometer overheating - is it due to current rating?

I need to get a pump running at different speeds so I ordered an electric motor, a potentiometer and a power supply adapter. I put them all together and they worked, however the potentiometer got ...
1
vote
7answers
152 views

Wire capacity - Total power or just current?

So I've gotten myself into a healthy, educational Facebook discussion. Link is here if you're a member of that group. When I thought about it, everyone defines wire capacity by current only. The ...
1
vote
2answers
164 views

How to build an electric rat trap / deterrent

I am looking to build an electric rat trap that acts like an electric fence, one that that can deter or block rats from climbing up a tree. Not interested in killing them. I have a large orange tree ...
0
votes
1answer
52 views

How many amperes can pass through drain-source of a FQPF9N50C if 3.3v are applied to gate-source?

I a playing around with this N-channel mosfet I found at home (FQPF9N50C). Using this simple circuit: I am able to turn on an off the 12v load using by connecting 3.3v to the mosfet. The load is a ...
0
votes
0answers
74 views

Calculating power from voltage (V) and amp (I) values

First of all I would like to say that I am not familiar with electronics at all. So we had an exercise during the lecture and the exam is soon. The professor calculated P value of 230V and 16A very ...
0
votes
1answer
57 views

Is this polygon pour, how much current can it carry?

On my attached picture, I draw battery pins, (red square) component that want to current, (blue square, a component want to about 4-6 ampere) and way of current (black line). I have a some questions. ...
0
votes
1answer
57 views

fault current through a person

Say a person touches the live wire as shown in the first attachment, the current will flow through him and dissipates into the ground as shown in the second attachment right? the fault current through ...
-3
votes
1answer
67 views

Determine the necessary values of v and i in the circuit

Determine the necessary values of v and i in the circuit. I want to know the working out of this problem please.
1
vote
2answers
118 views

Current capacity for Kanthal wire

I was given a Ceramics Kiln that is designed for 208V and I am trying to see if there is a way I can run it at 240V. It has 6 elements made of 16AWG Kanthal APM resistance heating wire. Each element ...