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

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3
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2answers
103 views

Finding the touching angle on a touch-screen?

I am wondering if it is possible to detect from which direction (or at which angle) a human touches a touchscreen. Imagine something like this: Is there any technology out there (e.g. special ...
0
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3answers
66 views

Capacitor rated for 100vdc on 5vdc board

As the title says, I have capacitors rated 100VDC 18pF. Can I use these on a board that uses 5V Max ? I can't really find any direct answer to that question. What I want to do is to put a crystal to ...
0
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0answers
18 views

On chip Interconnect : Coupling capacitance between bus lines

SoC interconnect lines have two sets of capacitance associated with them. The first being ground capacitance Cg(Capacitance between the interconnect line and ground plane) while the other being the ...
0
votes
0answers
35 views

How to prevent or slow down the discharging rate of capacitor once it has detected the peak values?

I have load cell-sensor that has a sensitivity of 2mV/V. I am using an instrumentation amplifier to amplify the sensor output depending on the load or force applied on the sensor. Followed by the ...
2
votes
0answers
35 views

Where can I find a good theoretical treatment of conductor shielding?

Suppose one has three current carrying cylinders lying on the same plane. Some of the electric field of the first conductor ends up on the second conductor, which creates capacitance \$C_{12}\$. But ...
0
votes
3answers
81 views

Why is the capacitor considered lossless, even if it can store/give out energy?

They say capacitor is lossless because average power is 0.But contradicting this is the fact that the energy stored/disipated by a capacitor is (1/2)CV^2.How and why is this?
2
votes
2answers
82 views

SPICE model for one terminal spherical capacitor

I have a circuit where at least some of the capacitance is coming from large, non-radiating, spherical conductors. I would like to model it in SPICE to better understand its operation-- is such a ...
0
votes
1answer
78 views

How would I measure an Ultracapacitor's Specific Capacitance using a PGSTAT128N?

I am building a capacitor using nanomaterial grown on a substrate. We are trying to figure out what our test fixture configuration should be when doing Cyclic Voltammetry on the cell. Our group would ...
0
votes
2answers
62 views

Resistors and capacitors calculation for 555 timer circuit

I am new to electronics and I want to try an experiment. I want to use a 555 timer to create an automatic food dispenser for my aquarium (something like opening a small door when the timer has ...
0
votes
2answers
56 views

How to calculte mosfet capacitors (Cgs Cds Cdg) knowing the charges Q

i need to use the best model fo the MOSFET in my circuit i'm simulation on PSIM, the MOSFET is Si4108-TI-GE3. But i am not given the parasitic capacitance values (Cgs Cds Cdg), i am only given this : ...
-2
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1answer
61 views

At what capacitance and voltage are capacitors harmful? [closed]

I'm currently building a taser from scratch and would like to know which capacitor to use.
0
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3answers
72 views

Series LCR experiment

i am doing a series LCR experiment for measuring the resonant frequency taking, R= 100 ohm; L= 40mH; C=0.1uF. I am using a 10KHz audio oscillator having 10V p-p as the input. I have fixed the input ...
0
votes
0answers
58 views

Measuring Capacitance using AVR

I am trying to make a capacitance meter with AVR Atmega16. I use of analog comparator inside micro. Means when negative pin(AIN1) of comparator reach to postive pin(AIN0) micro going to interrupt ...
1
vote
2answers
59 views

Capacitance of a single charged plate?

Lets say we have a single plate that has a charge of +Q on it. A plate with charge -Q is infinite distance away. Will the plate with +Q have a capacitance associated with it? Why or why not? I was ...
4
votes
3answers
269 views

Why are high values of capacitance in low pass active filters not recommended?

I am designing low pass active filter (Sallen-Key structure) and I have come to a point where I have to decide what should be the value of C (C1 = C2 = C) and then calculate values of resistances. I ...
-3
votes
1answer
100 views

Fundamental questions about capacitors? [closed]

I have read several chapters in several textbooks, watched several in-depth tutorials, etc. There are still somethings that were either not explained clearly enough for me, or not explained at all. ...
1
vote
1answer
46 views

If you put a MOSFET in backwards does the impedance change?

if I stick a MOSFET that should be going (S-D) to positive in backwards, and make it (D-S) to positive, all the current drops across the diode instead. This diode then approaches an impedance of 0. ...
0
votes
2answers
35 views

Power factor correction of predominantly inductive load component with capacitor

I started preparing for the college next year, and I came across this question: How can I express the capacitance of a capacitor which needs to be connected parallel to a predominantly inductive load ...
1
vote
2answers
39 views

How do I prevent a capacitive touch from registering?

I'm looking for a thin cloth-like material or something that I can treat materials with that will prevent a capacitive touch from occurring. Everything I've tried either is too thick, or still ...
0
votes
0answers
20 views

Rise time degradation by connecting to an input buffer

Suppose I have an imaginary 1.8V lvcmos output buffer and I know from the datasheet that it has an unloaded 10-90 rise time of 1ns. Now I'm going to hook up 6" of trace, to an input buffer who has an ...
0
votes
1answer
85 views

LC tank circuit feeding on op-amp, no oscillation?

Based on what I learned during this experiment I've built the following circuit using an op-amp configured as a buffer... simulate this circuit – Schematic created using CircuitLab The ...
0
votes
1answer
27 views

How to simulate parasitic reactances in a circuit

Does parasitic capacitance of a microstrip trace add to the value of a physical capacitor on the same trace? If one sees it as a series element, then it would seriously reduce the value of all ...
0
votes
0answers
28 views

Finding the input capacitance of this critical path

Hi so I'm trying to find the input capacitance of this critical path and then find the EF, Electrical Fanout, Cout/ Cin. Cout is given to be 10pF Okay here's my attempt at solving this. We know ...
1
vote
3answers
146 views

How to properly connect and drive varicap diodes?

can someone explain me how to connect and use varicap diodes? Please consider that I am a novice, so would be ok to use a clear and an exhaustive language/terms. Thank you. I often see these ...
1
vote
1answer
85 views

Measure I2C bus capacitance

We are trying to calculate how many I2C slaves we can hook up the I2C bus. We tried to run a square wave through a serial resistor and measure the rise time but we get a strange result. More nodes ...
0
votes
1answer
53 views

Related to varactor Diode?

I'm working on my project during this i face some problems... Here i mention my problem:- I required some variable capacitance whose range is C=0.05pF to C=0.5pF. So there is any variable ...
0
votes
2answers
33 views

reading capacitance on digital meter

So I bought this digital meter from radioshack because it tests capacitance. I have several caps on a TV power board, most of which are 47uf and 470uf with various voltages. when I check with the ...
0
votes
2answers
113 views

Understanding capacitive load conditions for a microcontroller

This is from a PIC24E microcontroller datasheet. My question is understand what does "load conditions for device timing" mean ? Does it mean in order to maintain timing (say for a high speed PWM ...
0
votes
1answer
56 views

Can two capacitors be used in series to get a equivalent capacitance in a circuit?

I am building a FM radio circuit and a 27pF capacitor(Ceramic) is required in that, but i don't have one. But i do have 56pF capacitors. So i was thinking that can i use two 56pF in series to get a ...
1
vote
1answer
43 views

Stray Capacitance in my load waveform?

I have just taken this trace of my Loadwave form for PWM controlled halogen dimmer. I was wondering if anyone could identify the cause of the transients below or above zero volts for each polarity. ...
2
votes
1answer
94 views

Trouble calculating time to drain a capacitor

Introduction I'm having trouble producing an equation that involving my MAX756 boost chip, a load and my 1.5F capacitor. Basically I'm trying to find out how long it would take for a 1.5F capacitor ...
4
votes
3answers
198 views

Simple ADC alternative by using a capacitor and digital Arduino pin

I'd like to measure a dozen potentiometers with an Arduino UNO. Unfortunately, the UNO only has 6 analog pins, but it does have about a dozen digital pins. Could I effectively measure an analog value ...
1
vote
1answer
109 views

How do I deal with different XTAL pin capacitance when selecting XTAL and load capacitors

I'm trying to select a 32kHz crystal and appropriate load capacitors for Atmega48A MCU. Atmega48A specifies different capacitances for Xtal1 and Xtal2 pins: 18pF for Xtal1 8pF for Xtal2 The ...
1
vote
1answer
84 views

What is power dissipation capacitance?

This question is derived from the answer to another question What is the input current of the 74HC595 The answer makes a note to the OP, that he should also consider power dissipation capacitance. ...
0
votes
0answers
48 views

How to switch on or off capacitance on a piece of conducting material?

I don't know if this is the right way of describing it, but I need to activate an area of capacitance on a touchscreen by applying some current to a piece of conducting material like tinfoil. I am ...
0
votes
2answers
106 views

Understanding to isolating sensor input capacitance

The circuit given above is pH sensor buffer circuit, picture taken from here. This circuit have pH sensor input and gives an output that can be read by multimeter which is U2's OUT_ pin . U1 is here ...
1
vote
2answers
200 views

How to calculate a electrolytic capacitor based on current and voltage to have the smallest ripple

I have built a circuit involving LEDs powered on 230V AC. The LED current driver that is powered on 30V and contains 10 LEDs of 1W each. 10 of these modules are linked in series and are ...
0
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1answer
45 views

Temperature Coefficient of Capacitance

How can I find the Temperature Coefficient of Capacitance of the following capacitor series: http://www.cde.com/resources/catalogs/TAS.pdf
0
votes
1answer
158 views

factors influencing capacitance of a cable

I am out of my depth here so I am looking for a simple explanation. If you have twisted pair cables of differing makeup, varying in conductive material, diameter of the conductor, number of twists per ...
2
votes
1answer
99 views

An “operation” game sensor where the stylus is NOT attached to the power source

Edit: The person operating the catheter will be wearing latex gloves. The only human tissue the catheter would touch would be that of the patient. Also, to clear up some confusion about what exactly ...
0
votes
3answers
90 views

help with capacitors and project

Capacitors have me crazy. I cant comprehend them even after lots of research. I know that capacitors deal with resistance, voltage, current and capacitance.(ohms, volts, amps and farad) but I cant ...
0
votes
0answers
51 views

Calculating capacitance at resonance

Could someone help me please asap, New to this ! Thank you! working out for the first one , could someone confirm? first question has been confirmed thanks Second question confirmation? thanks
1
vote
3answers
167 views

How to programatically simulate a click on a capacitance-sensitive button?

I am tearing apart a SONY HT-XT1, which has capacitive buttons to put it in a different case for a project: I've taken it apart already and am now met with a motherboard with 3 pads on it. Touch ...
2
votes
1answer
120 views

Did Capacitative Loading Kill My Op Amp?

I've been playing with various constant current source configurations to help control the current output of my bench power supply and my latest efforts centred around the op amp and MOSFET approach. ...
83
votes
13answers
22k views

Measuring feline capacitance

When I pet my cat, and then touch her on the nose, I get a little shock. Sometimes, when she walks up to something, her nose sparks and she jumps back and puffs out. I was wondering how I might go ...
-2
votes
1answer
97 views

What is the capacitance and/or inductance of a single straight piece of copper wire?

What is the capacitance and/or inductance of a single straight piece of copper wire? I know the answer is on Wiki, but I need for the answer to be supported. I know that Wiki provides references, ...
0
votes
0answers
75 views

Using capacitors to control the speed of a relay loop

Background: In my autoshop class at school we are required to make a circuit that uses relays. When one relay comes on the other one shuts off and it creates a loop in which they switch really ...
1
vote
2answers
203 views

Big capacitors measurement(LCR meter related)

I digged up some capacitors from amplifier and decided to test them, one of them is said to be 8200 uF, the other 4700 uF. I measured them with LCR meter and it gives very strange numbers. If LCR ...
0
votes
4answers
183 views

Capacity of a capacitor fully charged vs half charged

I read in most places, when people ask "can I replace a 10v 10uf with 100v 10uf?" and everybody answers "it's the same". Well... how can it be!?, I have a comparator circuit, that uses a little ...
0
votes
1answer
63 views

Need help with Relaxation Oscillator with Parasitic Capacitance

I am trying to build a capacitance meter using a simple relaxation oscillator with a fixed resistor R in series with a capacitor to be measured C. I am applying the formula where Freq=frequency and K ...