Capacitance is the ability of a body to store an electrical charge

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43 views

DC/DC converter/eFuse maximum output capacitance

I have some doubts about the design of this DC/DC converter circuit/PCB circuit: On the left side there is a 400V to 12V DC/DC converter (Vicorpower DC/DC Mini, 300W). The maximum output ...
2
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1answer
106 views

Why is the capacitance changing while measuring?

I have 2 different 100nF capacitors. Let's call them A and B. My dad told me that B is "better" than A. I've tried measuring their capacitance using a Metex multimeter which has the option of ...
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1answer
51 views

ACS758KCB Wiring Diagram

I am using the ACS758KCB Hall Effect sensor for a project. On the front page of the Datasheet it list a .1uF capacitor between Vcc and GND, in addition it lists a capacitor, Cf, between GND and ...
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36 views

Capacitance value - AC RC Circuit - Impedance Method

Here is the circuit: simulate this circuit – Schematic created using CircuitLab \$ V_i = \frac{8}{\sqrt 2} \angle0° V\\ V_c = \frac{6}{\sqrt 2} \angle45° V\\ R = 1000\space\Omega \$ ...
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70 views

How to select capacitor for my rectifier circuit

I had designed a rectifier circuit, in that I don't know how to choose capacitor. for example if I'm get in input supply as 9 V, now I want change it for 10 V, then how should I choose capacitor.
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33 views

Capacitor Units For Power Factor Correction

I have got the assignment to improve power factor of an industry. I have worked it out and found capacitance in K Vars and Micro Farads but need to know about the capacitor representation in volts?
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1answer
302 views

Crystal Oscillator not giving correct frequency

I have a 48MHz Crystal Oscillator (see here) that I am using as a clock for my microcontroller (EFM32GG332F1024). Looking at the datasheet for this crystal it seemed to me that the load capacitance is ...
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1answer
56 views

How is a reed switch used to charge/discharge a capacitor?

Ok, so there's no way to disguise this; I admit this is a question I've been set for homework but I can't find a full answer to. I know that, in brief, a reed switch consists of two metal contacts ...
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1answer
35 views

Capacitor with n electrodes

In my book it says that the capacitance in a capacitor with n electrodes is (n-1)*Co, Co is a capacitance of a two parallel plates capacitor. I know how to distribute charge when there are 3 parallel ...
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2answers
139 views

Does current flow stop when a capacitor is fully charged?

If I take a 1V battery and a 1 farad capacitor and a bulb and connect them in a circuit. Then will after the capacitor gets charged (not fully charged as that is impossible) will the bulb gradually ...
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0answers
63 views

Self tuning 125khz RFID reader

I have a RFID reader based on the EM4095 IC. I would like to make the reader self-tuning so it can handle varying inductance in the antenna due to reading tags near metal. I had thought of using a ...
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2answers
84 views

Capacitance - Voltage characteristic diagram in a Schottky diode

I 've searched the web for that diagram with no satisfactory result. Does a schottky diode has capacitance or not because of very tiny depletion (almost none) zone ?
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58 views

Do we ever use the pin capacitance of a digital circuit component (e.g ASIC, FPGA) in doing timing or data integrity analysis

As far as I understand, the pin capacitance on say an ASIC or FPGA effects the rise and fall time of the signal on it. It is also possible that the impedance offered by this capacitance to a very high ...
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2answers
230 views

How to make LC tank circuits oscillate continuously?

An LC tank circuit produces oscillations, when the capacitor is charged and connected to the inductor, but the oscillations decay gradually. How to make it continue, i.e. oscillate continuously? I ...
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0answers
74 views

How long of a wire and how big of a load can I have for SPI bus?

I have a system where I will connect up to 128 identical magnometer ICs up to an FPGA. I am trying to decide between SPI and I2C for comms. If I use SPI the setup will require 128 + 3 wires IF all ...
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0answers
88 views

Finding the value of capacitance for a given circuit

How would you know how much capacitance you should use in your circuit or is there any formula to compute on the desired capacitance you should use on your circuit? I have this circuit (figure shown ...
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1answer
57 views

Where does the power absorbed of this capacitor come from?

In my circuits book, the voltage across a capacitor is given as \$v(t)=100\cos({2\pi60t})\$. Because \$i_{ab}=C\frac{d}{dt}v_{ab}\$, we naturally compute the current as ...
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3answers
407 views

What happens to the capacitance of a system if capacitors are charged in parallel and then put into a series circiut

If you have 2 capacitors 2V, 2F each. When you charge them in parallel, the system will have 2V and 4F when you attach a load to it. If you take the charged capacitors and then put them in series, ...
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3answers
185 views

What does an inductor's current stabilize to in DC?

As you can see from the below graph, after an inductor is turned on, the current is stabilized to approximately 6.5mA. My question is: what does the 6.5mA represent? Where did that number come from? ...
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2answers
82 views

What's the definition of “signal to ground capacitance” of a coaxial cable? What's the difference between it and normal capacitance?

What is the definition of "signal to ground capacitance" of a coaxial cable. I know what capacitance is, but I'm not sure whether it is just the same thing.
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1answer
90 views

Application of charge conservation

I don't know how to start formulating equations or finding equations for this circuit, I have to prove this by mathematical equation. My adviser told me by charge conservation but I don't know how to. ...
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52 views

Charge conservation

How can I apply the theory of charge conservation for this charge pump circuit. Specifically on the pump circuit. How do I get the charges on the capacitors?
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230 views

How to design an square wave Oscillator Circuit with 1-20 MHz range?

I need a circuit that will generate square waves in a range of 1 to 20MHz. The circuit also should be adjustable in a scale of 0.05MHz for each step. There is no need for adjustments during the ...
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0answers
49 views

Diffusion capacitance

As far as I know, capacitance is created by two conductive plate with an insulation between them as they can store charges. When a diode is in reverse bias, it shows a capacitance because the n and p ...
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1answer
194 views

Solid State Relay Capacitance Bad for Audio?

Regarding MOSFET optocoupler relays like the Panasonic AQW212, am I correct in understanding that the capcitance between the terminals and ground when the switch is open ("off") is around 100pF when ...
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245 views

What is the role of the capacitor within the assembly

I have some questions regarding my assembly and especially on the role of the capacitor within the circuit. Before I added the capacitor I encountered 2 issues: when the piezo was squeezed (a ...
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1answer
116 views

Minimum number of capacitors

I require a capacitance of 2×10^-6 F in a circuit across a potential difference of 1kV . I have a large number of 1×10^-6 F is available which can each withstand a potential of 400V. Suggest a ...
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128 views

how to select capacitor for a crystal oscillator

Here is a 32 MHz crystal from one of TI's reference design The BOM list defines the crystal as ...
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2answers
116 views

Dielectric can be insulators?

People say that dielectric should be an insulator so that it can decrease net electric field increasing capacitance.. My question is if the object is a insulator how does the object get polarized ...
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1answer
261 views

What capacitors do when it is connected in Series and parallel to a AC input

I have seen in many circuits the capacitors are connected in series and parallel with the AC line. What the capacitor actually does when it is in series and parallel. I know capacitors passes AC ...
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2answers
132 views

Replace motherboard capacitor with lower capacitance?

Is it possible and safe to replace a motherboard capacitor of 1800uF, 6.3V with a capacitor of slightly lower capacitance 1500uF and the same voltage 6.3V? My motherboard does work, but it tends to ...
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72 views

Capacitive reactance

I'm doing AC theory as an electrical apprentice now, and my lecturer said that inductive reactance and capacitive reactance both work with Faraday's law, or back-EMF, is this correct for capacitive ...
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1answer
82 views

Measurement and characterization of a non-linear capacitance

Background I am studying a device that is a non-linear capacitance. In fact, structurally it is two parallel plates with a charged fluid in between the plates. The charged species of the fluid can ...
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1answer
150 views

Two-port network: find fundamental parameters

What is the easiest method to find the ABCD parameters? I tried replacing the middle part of the circuit (R2,L,C) with an equivalent impedance and then finding U2 depending on U1, but it is very ...
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137 views

How do capacitors maintain their charge?

If a capacitor is connected to a copper circuit and a battery, electrons would travel to one point of the capacitor plate, then a negative charge will build up because of the presence of excess ...
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2answers
107 views

Why are the values I'm getting through a capacitive sensor decreasing as the resistance gets lower?

I'm currently messing around with "capacitive sensors" by trying to light an LED using an Arduino. My capacitive sensor that I am using is just made up of an Arduino, three wires and a resistor. My ...
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3answers
141 views

Communicating with the moon via capacitance

In the question Capacitance between Earth and Moon, several answers gave a value for the capacitance between the earth and the moon at tens or hundreds of µF. Since capacitors are conductive to AC, ...
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3answers
2k views

Capacitance between Earth and Moon

Is there a capacitance between the Earth and the Moon, and if there was enough potential difference, could a discharge strike occur?
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1answer
160 views

Large photodiode capacitance

I'm working with an avalanche photodiode with a 320 pF capacitance. What exactly are the downsides of suc a photodiode with large capacitance values? I assume they would be slower due to the narrower ...
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2answers
130 views

Capacitance and Inductance properties of coaxial transmission lines

I'm interested to understand what affect the capacitance (between cable core and shielding) and the inductance have on a signal transmitting down a coaxial cable.
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1answer
86 views

Is to possible to measure electric signals using a capacitive touchscreen?

Thanks to a very good explanation by Mr. Ghosh, I found that a capacitive touchscreen measures the change in capacity, induced by contact with a conductive material, along a grid. I have two ...
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1answer
58 views

Calculate the capactance [closed]

If RV=22000 R=2200, how to calculated the C and what is the value?
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201 views

How to create a touch switch to use with a Raspberry Pi

I'm trying to make my own wakeup lamp. I have a lamp with a large metal base to hide all the components in. I also have a Velleman K8064 DC Controlled Dimmer Kit which I have put together and is ...
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1answer
94 views

LED only lighting up when my hand is hovering over it

I've got a pretty basic circuit, running an 10-segment LED bar graph through two TI HC595 shift registers. The very strange thing is that when I run the whole setup, and turn on a few of the LEDs, ...
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1answer
91 views

Find the capacitance of this rectangular slab of two films of metal virtually 0 thickness and 2 sheets of plastic. Then it is rolled into a cylinder

this question may be pretty simple for some people on this forum. Here's a basic image to go with the question. (also here) Two films of metal, virtually 0 thickness and 2 sheets of plastic. Find ...
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3answers
701 views

If MOSFET is a voltage-controlled device, then why do we need to supply it with high current when using in an H-bridge?

I might be confusing myself, but from what I am reading so far, a BJT is a current-controlled device and a MOSFET is a voltage-controlled device, which to me implies that a MOSFET requires very low ...
3
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1answer
82 views

Resistivity and resistance. Permittivity and?

We know that resistance is dependent on both the materials resistivity and the geometry of the material. For a cylindrical or rectangular material the resistance is: $$R=\rho*\frac{l}{A}$$ where l ...
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1answer
152 views

Capacitance of two wires with a grounded wire between

I have measured the capacitance between wires number, say, 1 and 3. With the wiree #2 just floating, the result was 390 pF. But after i have grounded the wiree #2, the capacitance was 220 pF. What is ...
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2answers
326 views

Making a grounded object capacitive

I am trying to make a copper pipe which is placed in a natural park capacitive. It is placed in the soil meaning that it is already grounded. I am using a basic arduino and their capacitive sensing ...
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1answer
74 views

load switch capacitance constraint

Considering using a Load Switch like DigiKey FDC6330LDKR-ND for powering on and off a device at the far end of a cable. The voltage and current requirements are well within spec however load ...