A message from our CEO about the future of Stack Overflow and Stack Exchange. Read now.

Questions tagged [charge]

A fundamental physical property held by various particles, most notably electrons

Filter by
Sorted by
Tagged with
0
votes
0answers
51 views

Using Solar Charge Controller with AC Power instead of Panels

I'm working on a project here which needs to have a small SLA backup battery. I have a cheap PWM solar charge controller already and I want to use plugged into an AC power supply (48V DC out) in ...
0
votes
0answers
73 views

Lithium battery charger and balancer circuit (or IC)

I am working on a project which sould charge and balance 4 to 6 (maybe 8 in future) serial connected lithium cell batteries (~4000 mAh capacity) with about 4A of charge current. First I looked for IC ...
0
votes
0answers
25 views

Solving for the current/charge across the elements of this RLC circuit?

I have a circuit which is composed of an inductor (L), capacitor (C), and two identical resistors (R1=R2): This represents an equivalent electrical circuit to a guitar pick or piano hammer as an "...
1
vote
1answer
39 views

How to calculate the total charge of a sphere which has a none uniform charge distribution?

If I am given a certain funciton which describes the volume charge density within the sphere with respect to the radius (ρ(r)),how can I calculate the total charge within the sphere.My idea was by ...
1
vote
3answers
74 views

Are charge and voltage in a capacitor always directly proportional, regardless of structure?

Capacitance is said to be a constant, and is defined as \$C := \frac{q}{V}\$. I have been unable, however, to find an implementation-independent way to show that charge and voltage are directly ...
0
votes
0answers
16 views

Charge Distribution on a Microstrip Line

let's consider a microstrip line connected to a voltage source V0 (applied between the strip and GND plane). According to foundation for microwave engineering (collin) book, the surface charge density ...
1
vote
2answers
34 views

Energising Electrostatic Charge Into Nylon Ribbons? Is it possible?

Forgive me for how high level this is but this is the goal I'm trying to achieve here: I want to build a device that has dangling ribbons of a material (lets say nylon for now) that can be actuated ...
0
votes
0answers
18 views

Using a TP4056 with a 08570 Battery

Will a TP4056 (the ones with mini USB and no battery protection) charge a 08570 battery safely? From what I can tell the battery does have built in battery protection but I cannot find much ...
0
votes
0answers
25 views

Charging small capacity battery with TP4056

I need to charge a battery which has 20mAh capacity. I have TP4056, is it suitable for this work? There is a formula Ibat=Vprog/Rprog*1200. If i set Rprog to about 100kohm,can i charge a 1C battery ...
0
votes
0answers
34 views

lithium ion charge controller with data pins

I have a Samsung powerbot vr9000 vaccumme cleaner. It stopped working one day and I found that the battery terminals do not have any voltage. I opened it and doubled the battery count with the same ...
0
votes
2answers
79 views

Charging a battery without overloading the rest of the circuit

I have a charger circuit (BMS) V1 which charges my LiFePo4 V2 battery, the battery also attaches to a circuit which can take a little more than 3.3v, however if for what ever reason the battery fails ...
0
votes
1answer
66 views

Is there a minimum for charging current for lead acid battery?

I've recently bought a 9 V, 3 W solar panel that I wanted to use to make a small project in my balcony, then I bought a 6 V, 4000 mAh sealed lead acid battery, I want the solar panel to always charge ...
0
votes
0answers
22 views

Difference between charge-sharing and charge-redistrbution

I've come across these two phenonmenon in several places but I want to know - what's the difference between them in a general two capacitor circuit case (not related to SAR ADCs) Like if I have two ...
0
votes
0answers
39 views

Question about charge and discharge of a capacitor

Let's consider the following amplifier: and suppose that a capacitor is connected between the output node and ground. Let's suppose that the inverting terminal becomes much larger than the non-...
0
votes
1answer
67 views

Any reasons why my 18650s go very hot when I charge them?

I have some PanasonXX 18650 batteries the grey and the green one I charge them in 2.5A 4.3v but I found that the green battery is very hot after I charge it about an hour later, I don't know the ...
-2
votes
1answer
86 views

How can a resistor be given a positive and negative characteristic?

This question is not pertaining to a circuit, but to individual parts itself. If for any reason, i want to make a resistor have a positive and negative charge on its either ends, what would be the ...
2
votes
1answer
46 views

Solar panel and power bank

I would like to charge a 20,000mAh power bank with a 18V 20W solar panel. The power bank has 8*18650 batteries in parallel. I came out with 3 options. The first one is to use a buck DC-DC converter ...
6
votes
6answers
2k views

How can electricity be positive when electrons are negative?

I don't understand how can a for example a battery be positive charged when the electrons are negative charged? I've read that protons are positive but they can't move so are all electricity negative?
0
votes
1answer
54 views

Question about a charge injection compensation network for analog switches

I'm studying this kind of CMOS switch: With the switch in Fig. 2.17 in the on state, after a transient, we have Vout=Vin hence the drain to source voltage of M1 goes to zero. The MOS enters the ...
0
votes
5answers
143 views

Why does a capacitor charge and discharge?

I know that a capacitor would resist a change in the voltage across its two ends. Assume that the capacitor in the diagram is a fully discharged capacitor( 0v across its ends). Now if I connect this ...
1
vote
1answer
45 views

Inrush control circuit

I am analysing the an eval board circuit for a battery charger IC which has the following inrush control circuit. Question 1: I understand that C22 is used to "slow start" Q6 limit inrush current ...
0
votes
1answer
73 views

high current UPS ish design

This is my latest attempt to try building a ups ish system for my 3D printer the printer is custom-designed with 5 meters (no, it's not a typo) on each axis. we use MKS Gen v1.1 with custom marlin ...
2
votes
6answers
176 views

True or false: A capacitor stores energy for ½ a cycle and gives it up on the other half, the net energy is zero

I'm hoping someone can give me some more information so that I can confidently answer this question. . . True or false: A capacitor stores energy for ½ a cycle and gives it up on the other half, the ...
0
votes
1answer
47 views

Voltage Doubler - Charge Pump

The basic understanding of this that I have is that: Assume clock low is 0V, clock high is 3V and Vin is at a fixed 3V. Ignore diode drops Initially Clock is low (0V) and Vin is at 3V (always). ...
0
votes
1answer
38 views

charge capacitor in two phases

i want to charge two 25F Supercaps (in series) in two stages: while their total voltage is under 5v, i want to charge them slowly via a resistor R3 of around 100 Ohm. After they reach the desired ...
3
votes
2answers
119 views

Finding the voltage across a inductor in a charged RLC-circuit

Well, I've the following circuit: simulate this circuit – Schematic created using CircuitLab In the circuit I want to find the voltage \$\text{V}_{\text{Y}_1}\left(t\right)\$ as a function ...
0
votes
3answers
40 views

phone charger residual electric flow

Not actually sure if this is too simple a question for this exchange. Just now I picked up my phone charger and unplugged it to move somewhere and plugged my phone in to the recently unplugged (from ...
0
votes
2answers
86 views

Removing a charged coil from circuit

I have a question: If I charge a capacitor through a resistor and remove it from the circuit, the capacitor will be charged for a certain amount of time (eventually the voltage across the capacitor ...
0
votes
0answers
31 views

What does this ɣ constant relate to in the carrier motion of BJT

What does the constant ɣ represent in the following carrier motion of an PNP transistor? So I see three components for the base current. 1) According to the illustration I can see that some of the ...
0
votes
1answer
653 views

How to calculate gate charge time for a mosfet?

I am designing the circuit shown above using mosfet NDS355AN. MCU is 5 V. However, I have become stuck as I am unsure of how to calculate the gate charge time of the mosfet. Hence what is the formula ...
0
votes
0answers
35 views

Simplified eqn for inductor charge for short timeframe?

In a worked solution my professor has given me it says: I(load) = Io(1-e^(t/time constant)) and I(load) = Io * (t/time constant) (for a short time period) I don't understand how the second line can ...
0
votes
2answers
67 views

Calculating charge given current and capacitance over time

I it possible to calculate the charge on a capacitor when only having the current, time and capacitance value? I tried using this formula to first calculate the voltage and from there the charge. ...
0
votes
0answers
118 views

How to switch between charge and discharge?

I want to make my rpi 3 portable with adding a rechargeable battery pack to it. I have 6 Li-ION batteries that are packed together in 2 series rows of 3 batteries in parallel(each battery is a 3.7 ...
1
vote
2answers
155 views

Battery operation, charge and discharge processes misconceptions

I'm trying to elaborate a simple explanation (and conceptually correct) of how a battery charges and discharges, and why we say things like "the charge stored in the battery is x Ah". For now, I have ...
0
votes
1answer
89 views

Transfer charge from a battery to another battery storage

I am conducting a feasibility study and one of the features of our innovation is that the "charge" that has been stored in our "Li-Po battery" can be transfer to another "battery storage" I would ...
0
votes
1answer
51 views

Optimal Grounding for a PVC Dust Collection System?

It is common in woodworking (A hobby of mine) to make a dust collection system (Basically a tube hooked up to a vacuum to carry away dust created from automatic woodworking tools) out of PVC. We'll ...
3
votes
2answers
159 views

How to determine the steady state voltage across two capacitors in parallel

Say we have two capacitors C1 and C2, initially isolated from each other and each having an initial voltage Vc1 and Vc2 respectively, where Vc1>Vc2. When suddenly connected to each other in parallel, ...
2
votes
0answers
59 views

A conductive ball connected to a capacitor

I am not asking for a task solution, but rather how to solve a problem. Say I have a ball of radius R, charged to a voltage of U (relative to the ground). I also have a flat capacitor with a side ...
7
votes
3answers
2k views

If a lithium cell is said to have a capacity of 20 Ah, does that mean all 20 Ah can be used?

Toshiba's SCiB 20 Ah Lithium titanate cell is said to have a nominal capacity of 20 Ah. The cutoff voltages are 1.5 V and 2.7 V. Does this mean that all 20 Ah of charge exist between those two cutoff ...
0
votes
0answers
318 views

Connect backup battery pack with BMS HX-3S-01

I want to connect a LiPo 11.1V battery pack with HX-3S-01 BMS board to my circuit. I found some other boards with separate power input and and output. But this one has only one (Charge/Discharge P+-)....
2
votes
1answer
200 views

Charge Injection Confusion

I'm having some trouble understanding the effect that charge injection has on capacitors - more specifically, when there is unequal charge on a capacitor. Consider the following circuit: My ...
1
vote
0answers
34 views

Responsible Battery Reserve Capacity and Low voltage?

It's been asked here, but looking for clarity. How bad is it to undervoltage a 12-volt lead-acid battery? SLI automotive starter batteries list RC (reserve capacity), but I think this a usable ...
0
votes
1answer
35 views

Charge Measurement for Piezoelectric Sensor

I want to measure the charge displaced by a force acting on a piezoelectric sensor. The problem is I don't know the sensor so I have no idea how big the current generated by the sensor may be nor what ...
0
votes
4answers
177 views

Supercapacitor backup circuit - why seperate charge and discharge path?

I am learning about super capacitors in a backup power application. I see a lot of examples using diode networks or FETs to separate the charge and discharge paths. Why is there so much effort put ...
12
votes
3answers
684 views

How much do lithium polymer batteries expand in volume?

I'm designing a device with a small lithium polymer battery (4x12x30 mm, 120 mA-h). Looks like this: I've heard that there is a rule of thumb that the space left for the battery in a case should be ...
0
votes
2answers
306 views

How to charge two 18650s in series without a middle connection?

I have a battery pack of 2 18650 cells in series, so it is possible for me to charge it without connecting anything to the central 3.7v potential point as many answers mention? The battery in question ...
1
vote
2answers
48 views

Something wrong with open USB circuit, electrostatic problem

I faced a strange problem with the following circuit. I'm using some buck converters and an Arduino. The buck converter (Vout = 5.25v) is for a USB charger (up to 2 Amps). Well, I think the circuit ...
0
votes
0answers
57 views

If we're wearing a metal watch, do we get an electric shock on our wrist when we're charged and touch a conductor?

Or if the conductor itself is charged. As the charge would flow to/from the watch, assuming I'm insulated from the ground with rubber soles, or standing on glass.
0
votes
1answer
71 views

How does a camera pixel accumulate charge (colour)?

I refer to the Wikipedia entry for a CMOS camera sensor's individual pixel. There is a schematic like so:- and a statement that:- The read-out transistor, Msf, acts as a buffer (specifically, a ...
0
votes
4answers
281 views

What happens to the energy stored in a short-circuited capacitor?

Suppose we have an ideal capacitor with a certain voltage between its plates. We connect the two plates using an ideal (lossless) wire, so the capacitor discharges. Where has the energy having been ...