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

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23 views

Capacitor voltage influence

I am new to electronics and have been learning from educational kits and from the web.These days I have looked up the timer ic 555 and was wondering how does this ic detect the voltage variation of ...
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28 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 ...
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1answer
56 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 ...
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1answer
62 views

Capacitor to slowdown the RPM of the Motor [on hold]

Thank you for the help, after confusion, apparently there are cogs in place to slow this down, I am trying to source a Start Capacitor to force the rotational direction. Here are a few details: ...
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1answer
54 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 ...
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0answers
23 views

AC Motor Starter Capacitor - humming sound after replacement [on hold]

A tumble dryer stopped working and I found it to be the starter motor capacitor (when switching the dryer on, the drum would not spin but if you manually started to spin the drum, the motor would kick ...
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0answers
34 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 ...
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2answers
45 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. ...
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3answers
77 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?
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2answers
239 views

What's the purpose of having two of the same value caps in parallel?

Why does this 5V circuit use two of the EXACT same value capacitors? It's not needing a larger capacitance issue considering 100nF is relatively small. Here is the full schematic: Arduino Leonardo ...
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31 views

Composition of sticky gel in Film Capacitors

Bit of a long shot here, maybe someone knows what the sticky clear gel might be inside common dual film can capacitors (motor run). I'm specifically looking for an MSDS. This particular one was ...
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66 views

Can I replace a SMD capacitor with an equivalent through hole capacitor? [closed]

I've got a dead laptop motherboard that has been laying around for few years, recently I noticed this blown up SMD capacitor on the board: After checking the board schematics it turned out to be a ...
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1answer
69 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 ...
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0answers
40 views

Quasi-peak detector

This is the circuit of a quasi-peak detector: simulate this circuit – Schematic created using CircuitLab where \$ V_{sig}\$ is the input signal. When the diode is open-circuited, the ...
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4answers
87 views

What will happen when two capacitors C1 and C2 are added in series instantly by a switching mechanism, How the charge sharing will take place?

Suppose there are two capacitors ( of capacitance suppose C1 and C2 ) .There is a switch S1 between them which is open for lone time .Initially the capacitor C1 is charged to a voltage V1 volt .Now at ...
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2answers
55 views

How to read capacitor code u10j63? [closed]

I need to find these capacitor immediately. How to read these values? I am pretty sure they are metalized polyester film capacitor. But I don't know what values they are? Capacitors look like this.
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1answer
61 views

Burned Out Tantalum Capacitor Replacements

I have an old computer with a broken Miniscribe 8425SA hard disk. One of the capacitors has burned out, and need some help finding a replacement. Here are my questions: It appears there are ...
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1answer
68 views

RC-circuit - DE

Yesterday I was browsing through some questions in preparation for my exam and I found this one: Consider the circuit below consisting out of a capacitor C and two identical resistors R. For ...
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2answers
53 views

Low Voltage AC Smoothing Capacitor Calculation

I have a 9V AC source which will have a max load of 100mA. I'm trying to figure the value of a smoothing capacitor with less than a 10% ripple. I don't have a scope or else I'd just try a bunch out. ...
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2answers
31 views

Circuit with switch - express the current for different times

Consider the circuit below consisting out of a capacitor C and two identical resistors R. For \$t<0\$ the switch is open and the capacitor is uncharged. At \$t=0\$ switch is shut and the circuit ...
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24 views

Bootstrap capacitor selection considering parasitic current

I have been trying to determine how to calculate a bootstrap capacitor value for a synchronous gate driver IC implemented for a buck converter. I understand the the demand of the MOSFET gate itself ...
2
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1answer
31 views

capacitor and resistor combination

I'm currently working on some simple circuits to learn about circuitry, and being a Physics major I have a pretty good grasp of the mathematics and concepts, but I'm a little confused about ...
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1answer
39 views

Help Identifying Radio Component and Replacement Part

My girlfriend picked up an old Philco tabletop AM radio. If I had to guess, I'd say it was manufactured around 1960. I couldn't find any model number or year stamp. It's encased in plastic. It powered ...
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61 views

Will changing my capacitors for ones with higher voltage but same microfarad allow me to use higher voltage batteries

I have a r/c car that I'd like to use 8 of the 3.2v AA batteries instead of the typical 8 1.2v AA. There are two capacitors one is 2200uf 10v the other is 220uf 16v, if i replace them with 35v of the ...
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2answers
28 views

RC circuit with lossy capacitor

This circuit simulate this circuit – Schematic created using CircuitLab can be regarded as an RC series circuit with a lossy capacitor. The time expression for \$V_C(t)\$ with \$R_2 \to ...
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4answers
735 views

Capacitor connected directly with battery

This may be a dumb/begginer question, but I'm having trouble to understand what exactly happens when we connect a real capacitor directly with a battery. In my understanding, theoretically, when an ...
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1answer
26 views

Finding current in AC circuit, coupled coils

Freshman introductory problem, AC circuit.Coupled coils. Here it is: simulate this circuit – Schematic created using CircuitLab So I need to find the current through the voltage ...
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1answer
55 views

Step-down converter and ceramic minimum ESR capacitor

I'm building a step-down converter, based on the TI TPS5450, which provides a reference design and various considerations on the capacitor. Even on the minimum ESR required. But when states "The ...
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2answers
62 views

Difference between capacitor start and capacitor run Induction motors?

All though in both types of Induction Motors, capacitor does the job of phase shifting to produce the rotating magnetic field, their working principle is the same. Then whats the point in ...
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42 views

High pass filter DC blocking equations

Given a 12 volt DC supply to a potential divider circuit and a coupling capacitor connected to a 40 mVp AC, how would I confirm that the resistance between ground and capacitor is low or high enough ...
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2answers
86 views

why do rectified voltage boosts after adding a capacitor?

So I found this 9V 1A AC power supply laying around and decided to make a DC source. I rectified and added a capacitor to make things a bit even. After adding a capacitor my voltage boosted from 9V ...
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1answer
80 views

Is it ever useful to add a capacitor between op amp inputs?

Is it ever a good idea to add a capacitor between the inputs of an op amp? I'm building an electronic load roughly inspired by some of the Dave Jones derivative circuits out there. I've adopted the ...
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4answers
165 views

How to test analog component before mounting?

I have been in a small factory today, they produced 4 kind of PCBs that all are simple analog boards, each month they produce 1000 of them. The problem is that till now, after mounting them almost 10% ...
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1answer
43 views

Using a capacitor to properly power a servo

I recently attached a servo to my Arduino for the first time. I ended up needing a 470uF capacitor wired like this tutorial shows because my servo was freaking out and causing my laptop to throw ...
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1answer
106 views

Problem understanding the operations of capacitor

So far I've learnt about some different types of capacitor arrangements , such as coupling , decoupling , bypass , filtering , and smoothing capacitor. Decoupling and bypass capacitors are the same ...
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1answer
57 views

charge a 15v Cap with 24v

Can I charge a 15V Cap with a 24V supply, as long as I have the supply disconnect, once the cap reaches 15v ? I have seen the analogy of comparing the voltage to the max psi of a tank, and if you go ...
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1answer
79 views

Where does j come from in the reactance of L and C components?

So the reactance of the inductor is jωL while that of capacitor is 1/jωC. My question is that starting from the differential equations that describe the dynamic behavior of these circuit components, ...
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1answer
67 views

homemade capacitor - crafting and testing

i'm a laic when it comes to electronics, but i want to venture myself in creating things with my own hands. looking for that i come to see a tutorial that teaches how to make a capacitor with foil ...
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1answer
51 views

Explaination of high current zener transistor regulator circuit

This is a high current zener TRANSISTOR regulator circuit. I want to know What does "high current" mean here? How is this circuit working as a zener regulator? What is the purpose of transistor ...
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1answer
60 views

How do I work out the time when given current in a RC circuit?

So this exam question looked straight forward, but I can't get the right answer. I'm trying to find the time, from when the switch is close,that the current will equal 2mA. I've used a few formulas ...
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30 views

circuit for switching on and producing desired high pulse then circuit turn off without using micro controller

i have no prior knowledge about electronics , but i am trying to make a circuit that turns on the switch after 10 seconds and then produce a desired length high pulse say 30 seconds then it turn off ...
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1answer
200 views

What does this schematic of an Op-Amp and Capacitor mean?

I'm still learning about electronics and electricity. But I'm puzzled by this question from a past exam. I'm not sure if any voltage is getting across the capacitor, since Vin and 3v are seperated ...
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2answers
636 views

Why are caps configured this way in EMC filters?

Every EMC filter I've seen has capacitors between the AC lines and earth, configured like this: simulate this circuit – Schematic created using CircuitLab Why are the caps not configured ...
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1answer
40 views

Difference between Across the Line and Line to Earth

I have to make a reverse engineering. I have two different type of capacitors. What do the Across-The-Line X2 and Line-To-Earth Y2 mean? And what are the differences between them. I searched it but i ...
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1answer
58 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.
3
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1answer
97 views

What is the best modern replacement type for a metalized paper capacitor?

I have a couple of old power supplies in which Rifa brand metalized paper line filter capacitors (for 240V mains power) have failed - or may fail - like in this question here. 30+ years sounds pretty ...
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2answers
91 views

Capacitor Configuration

The block diagram below is for a simple use of a solar array in conjunction with a battery, in a battery tied bus format. The diagram is simple and straightforward excepting the capacitor ...
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2answers
38 views

Using a supercap to charge a MLCC

Is is possible to use a 4V supercap (say ESR = 100 Ohm), to charge an X5R ceramic capacitor (assume also 4V)? I think this is possible, so my second question: is there a way to calculate/estimate ...
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1answer
60 views

Can I get help with measuring particle charge using oscilloscope?

How can one measure particle charge using oscilloscope and op amp integrator circuit along with a capacitor and faraday cup. I am unable to figure out how to approach. I have the circuit ready but ...
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2answers
36 views

Insulation resistance and leakage current in capacitor

I am using the capacitor in a battery powered device but unable to find the leakage current. They have mentioned the insulation resistance minimum as 10 GOhms. Can I take this into ohms law to find ...