A fundamental electronic component that stores energy in an electric field, commonly used in filtering applications.

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3
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1answer
47 views

electrolytic capacitor minimum voltage?

Do electrolytic capacitors have a minimum voltage to operate? Im pretty sure they dont but anything below 7v and 1A will not power the circuit with the capacitor in added.
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1answer
38 views

Capacitor based power supply circuit for LED bulb

What is the function of ac capacitor in capacitor based power supply ?And is this power supply will be reliable enough to run a LED bulb
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1answer
50 views

Can you ground the dielectric of a capacitor?

To measure the soil moisture of a house plant, I've put two knives in the soil (covered with shrink sleeve), and attached a capacitance meter. The dielectric constant of water is really high, and as a ...
0
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1answer
36 views

Please, check my solution of RC circuit

I have solved a problem, but I am not sure if it is right. For me my solution seems to be too straightforward. I have tried using KVL and solving differential equation for current, but the final ...
0
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2answers
68 views

Charging a capacitor with MOSFETs

I have this circuit: simulate this circuit – Schematic created using CircuitLab The idea is that a high at Vcharge will charge the capacitor and then a high at Vdischarge will discharge ...
0
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0answers
32 views

Capacitance when the dielectric medium is heterogeneous?

Suppose we have a parallel plate capacitor with a dielectric between the plates. However, the dielectric is not homogeneous: most of it has permittivity e1, and a pocket of it has permittivity e2. ...
0
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1answer
58 views

50v capacitor in a 40v circuit

I am Making a Power Supply, There is a 40v rail that needs a 10000uf cap, I was wondering if it is safe to use a 50v rated cap, Should i be worried that it is close to the Limit? The Brand of the ...
1
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2answers
75 views

Calculating the discharge of Ultra Capacitors

Say I have two 500F ultra capacitors, connected in parallel, charged at 15V. These are the capacitors BMOD0500 P016 B01. Then say I connect the capacitors (via an inverter) to a 230V light bulb that ...
24
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8answers
4k views

Why does a capacitor block DC and not AC? [duplicate]

If someone can explain why a capacitor blocks DC, but not AC, with some math, I will understand all of that much better. I know that there are picture animations illustrating this, but I really want ...
0
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0answers
32 views

How to measure the capacitance of a capacitor? if labeled, what are the instructions to interpret it's tag… and instructions for the unlabeled

How to measure the capacitance of a capacitor? I believe this question will be answered with categorization. ex. by looking at the label (104, etc), by solving its value through calculation... the ...
0
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2answers
60 views

Can capacitor charge to higher voltage than source provides?

Hi I played with some basic circuits in lushprojects.com simulator and came up with this one that surprised me - when the capacitor C1 is charged for the first time by pressing the SW1 switch the ...
1
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0answers
30 views

one-sided saturation with op-amp and RC high pass filter

I am working with a photodetecting circuit built as follow: When I drive an LED ON and OFF, I get the following waveforms: Blue indicates that the LED is turned on when a voltage is high and ...
1
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2answers
84 views

Capacitor safety

After looking at some posts,I started wondering if using capacitors,especially electrolytic ones is as safe as I thought.After making sure that the you don't supply a bigger voltage than the rated one ...
1
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1answer
84 views

Tolerance of a ceramic capacitor

I have a ceramic capacitor that reads "101 Suntan" (and nothing else.) Reading up on how to interpret capacitor labels, I believe this capacitor is 100pF. I'm having difficulties trying to determine ...
0
votes
1answer
48 views

capacitor for led strips

I want to make a DIY Power PUC to put led's on my motorcycle. I plan to use 5050 RGB strips. Power supply to these LED's will be in the form of a carbon brush - aluminium ring assembly. But since the ...
1
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1answer
53 views

About the combination of two signals with capacitors

Here is a link of an article I've been reading. http://www.analoguehaven.com/moog/thereminblack/hotrod.pdf In page 4 there is a circuit schematic. Notice there is a part called variable pitch ...
2
votes
1answer
82 views

Why capacitors lose charge over time? How to minimize it?

Capacitors lose charge over time, even when they are disconnected. Why does it happen? Is there a way to keep the charge longer, like for years. If you cover the plates with better insulator, will ...
1
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1answer
32 views

Computing capacitor voltage through series connected diode

I have been trying to analyze this circuit and calculate the maximum voltage across the capacitor. Here is the diagram: And, here are the graphs for various inputs and the resultant outputs: ...
8
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2answers
415 views
+50

Inductive and capacitive terms

What it means when we say that some component or device is inductive or capacitive? How these terms are related to capacitors and inductors?
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 ...
1
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2answers
336 views

Quick question about aux cable DIY

I've been planning to make an aux cable for my BMW 3-series, because the original costs 80€... So I've read a couple of DIY and I've found this So I've ordered the cable, capacitors, and the ...
0
votes
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 ...
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3answers
72 views

Capacitor vs battery which cost less per capacity? [closed]

I know that batteries have better density ie capacity per volume. But I want to get the most energy capacity for the money. Which one would would you get? I'm trying to store energy from solar for 1 ...
0
votes
3answers
51 views

finding angular frequency when current is maximum in circuit

A series of ac circuit consist of an inductor and capacitor. The inductance and capacitance are 1 henry and 25μf. The current is maximum in circuit, then what will be the angular frequency? The ...
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2answers
55 views

Physical changes caused by charge pump

Charge pumps are very cool circuits because they challenge my ideas about how voltage works. I'm very comfortable with the math behind line integrals, so to define "voltage" as the work done to move ...
2
votes
2answers
94 views

Why does and increase on capacitor ESR makes the capacitor hotter?

According to what I have read online, if a capacitor ESR increases, the capacitor temperature will also increase and this has me a little confused. Consider the simple single resistor circuit below: ...
0
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1answer
24 views

Can I use an electrolytic capacitor with a MCP1826S voltage regulator?

I have a MCP1826S and according to the datasheet, I should use an output capacitor of 1-10uF and with an ESR of lower than 1Ω. I have some 4.7uF electrolytic capacitors, but I think they have an ESR ...
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0answers
77 views

State Equations

Please can you help me in finding the state equations for the circuit below? My problem is the two capacitors. How will we cater for the second capacitor? I only know problems with 1 capacitor and 1 ...
3
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3answers
483 views

what is the meaning of NOP in the schematic diagram?

what is the meaning of NOP in the schematic diagam?
0
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0answers
40 views

algebraic addition and subtraction within RC and RL

Why isn't it possible to algebraic add the potential drop of R and L within a serial circuit using alternate current? And why is ...
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1answer
93 views

Make: Electronics (Experiment 11) LED blinks only once

There is one more question about Experiment 11 from "Make: Electronics" by Charles Platt. The trouble is that my LED blinks only once, when I connect circuit to power source. (I tried 6V, 9V and ...
0
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3answers
62 views

How to find the correct graph for variation of capacitance with time.?

First of all I have to admit that this is a homework type question. Figure below shows you the question My thoughts towards this question Capacitance for parallel plate capacitor is given by ...
2
votes
2answers
48 views

Measuring leakage current in a capacitor

I've recently been hired in a lab at my university to continue research on supercapacitors, specifically leakage resistance. The former student who set up the current tests was a chemist so the ...
0
votes
1answer
35 views

Different time constants for charging and discharging of a circuit with a constant current source and a capacitor

Consider a circuit that only has a constant current source and a capacitor. The voltage across a capacitor is proportional to the integral of the current I, times time. Since the current is constant ...
0
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2answers
53 views

Math of capacitor current/voltage when connecting capacitor to battery

I think I'm missing something fundamental in the math surrounding capacitors. Suppose I have a 1 F capacitor that is not charged. The voltage across its terminals is 0 V. Now suppose I connect a 1 ...
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0answers
37 views

Finding equivalent capacitance between P and Q

Figure below is the schematic diagram ,there we need to find the equivalent capacitance I know that this is a straight-forward question for most of them, because many of you are expert in the ...
0
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0answers
34 views

AVR decoupling capacitors in 64kHz switching power supply

I am working on a compact variable switching power supply (sepic topology) that is controlled by an Atmega328p microcontroller. The unit is powered by li batteries at 3.7 volts. Everything works ...
0
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0answers
54 views

Do this work the same way? (capacitors)

Hi guys, I have a question... Is this two circuits the same? Like... will the capacitor act in the same way on both? I'm asking this because i'm looking to the first picture and I think that the ...
3
votes
1answer
44 views

How to replace a SMD capacitor on a raspberry pi?

(Note: also posted first in raspberrypi stackexchange, but not a single answer yet) While desoldering the GPIO, I accidentally broke the capacitor C13 of my raspberry pi model B (2011.12 Rev7). It ...
3
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2answers
201 views

What does a capacitor “Series” signifies?

I am an electronics beginner trying to shop online for capacitors but so far I am failing miserably. My biggest question right now has to do with capacitor series. Below is a list of a couple of ...
0
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1answer
82 views

How to analyze this circuit with resistors and capacitors?

I have to find out the value of \$V_{o}\$ and \$V_{c}\$ initially and finally of the this circuit when \$S_{1}\$ and \$S_{2}\$ switches are simultaneously closed. Edit: \$V_{c}\$ is across the ...
0
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1answer
70 views

Why is the 1uF capacitor needed in this load-sharing circuit?

Consider the following circuit that describes a MCP73831 battery charger with a load sharing circuit: Why is the 1uF capacitor needed? I realize that the 4.7uF are there to reduce "noise", but why ...
4
votes
3answers
483 views

How to select proper capacitors and capacitance for LM78xx voltage regulators?

I want to use LM78xx voltage regulators for various projects. I want to know in general, how should I choose a correct value for input and output capacitors of LM78xx family when I want to change DC ...
1
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1answer
42 views

Help identifying ceramic disc capacitor

I have a blue ceramic disc capacitor and I'm trying to work out the values. On one side of the disc are the following characters, in approximately this pattern: ...
1
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3answers
96 views

Capacitor voltage influence

I have edited the question to make it easier to explain what I am asking for.To make it clear , I have deleted the part with the 555 timer. I have a question regarding the following : I know that ...
0
votes
1answer
41 views

What voltage rating should capacitor be in this LED driver circuit?

I have a circuit that is used to rapidly turn an LED on and off. There is a capacitor in the circuit to provide some buffering (C1). What minimum voltage rating is required when selecting C1? I want ...
1
vote
1answer
62 views

How to figure out how much time you have for writing to flash when voltage source breaks down?

I try to figure out how I can make sure, that my controller (STM32F030K6) is always able to save a 16 bit integer to the flash when the power is breaking down rapidly. This controller has an Analog ...
0
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1answer
59 views

Shunt capacitor as discontinuity in transmission line

As in the following circuit simulate this circuit – Schematic created using CircuitLab suppose that an infinite transmission line (with characteristic impedance \$ Z_0 \$) ends upon a ...
0
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0answers
35 views

Analyzing a circuit with given effective values, freshman EE

Here's the circuit: simulate this circuit – Schematic created using CircuitLab Values: Voltage shown at the volt-meter, 11V Current shown at the ammeter, 5A Current generated at the ...
3
votes
6answers
342 views

Capacitor selection for filtering of low level signal

I am currently dealing with low level signal(voltages in milli-volt from the sensors) for the first time. I was advised to use filtering circuit moreover RC filtering which I have already implemented. ...