Questions tagged [capacitor]

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

631 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
3 votes
2 answers
99 views

Increase magnetic power from a coil

I'm building a project which basically consists of the electronics inside a lucky cat: a coil that generates a magnetic field to make a permanent magnet move, which is attached to a swing. Check this ...
user avatar
  • 31
3 votes
1 answer
106 views

Ceramic Capacitor 10uF NP0 Cold Temperatures

For my pcb which will be used at very low temperatures, say 50 K, I am searching appropriate Bypass Caps. Many papers stated that NP0(C0G) Caps are especially good because of their constant ...
user avatar
  • 101
3 votes
0 answers
137 views

Arrangement of Capacitors in a Railgun

Nearly all of the railgun designs I've seen have arranged the capacitors in parallel. Why is this? If one arranged the capacitors in series, couldn't they achieve a higher voltage (and thus more ...
user avatar
3 votes
1 answer
200 views

Failure Rate calculation based on manufacturing defects (capacitor)

Electronics failure rates typically follow the exponential distribution and models like Prism, Mil-Hdbk-217 or 217Plus (newer) are used to predict failure rates. We are currently in the production ...
user avatar
3 votes
0 answers
681 views

PCB trace caps (a.k.a. finger / interdigital caps) formula

I am trying to calculate a two-fingered, both on the same layer, capacitor. I have run into a few papers on it but they are taking a ground plane on the other side of the PCB into consideration and ...
user avatar
  • 807
3 votes
1 answer
330 views

What characteristics for 3D-printed capacitors made of interlacing conductive filament?

There are conductive filament for 3D printers which seem to have between 30 and 115 ohm/centimeter resistance depending on the axis. (Proto-Pasta conductive PLA) They can be 3D printed as a capacitor ...
user avatar
  • 31
2 votes
0 answers
107 views

Capacitors exploding on PWM motor controller

I'm part of a project in which we are developing a PWM controller for a 24V DC motor. Our current problem is choosing a capacitor to replace C1, which keeps exploding. We've been running tests at ...
user avatar
2 votes
0 answers
49 views

Current Direction and Voltage Polarity in Capacitor/Inductor Circuits

I believe that this question may be simple for those with a little more experience, but it is still puzzling me. Studying capacitance/inductance, I understand that the capacitor in the DC case behaves ...
user avatar
2 votes
0 answers
72 views

How to indicate an android tablet is actively charging with LED?

I am a rank beginner, and I do feel like I am missing something pretty obvious here, as the problem doesn't seem that complex. (I know... famous last words) Problem: Android tablet (in a completely ...
user avatar
  • 121
2 votes
0 answers
168 views

Capacitance through a diode

As I was designing power circuit, I have a place where two power rails come together with Schottky diodes (power from battery vs power from charger,) similar to what you can find in phones or laptops. ...
user avatar
  • 3,318
2 votes
1 answer
67 views

Electrospray Deposition

I recently got a new project to work on, an Electrospray Deposition setup. Basically, it consists of a needle that contains a liquid, a electrode and a high voltage source. The needle is positioned at ...
user avatar
  • 21
2 votes
0 answers
716 views

Calculating the capacitance for a voltage multiplier circuit

Recently, I've been asked to create a voltage multiplier, with an output voltage \$Vo = 5*Vi\$, where \$Vi\$ is the peak input voltage. This was accomplished without much issues through the schematic ...
user avatar
2 votes
0 answers
66 views

Large variations in capacitor cost

I am very surprised with difference in capacitor cost (up to 10 times) like this and this. These two have same capacitance along with voltage rating and tolerance level.Then what are the reasons ...
user avatar
2 votes
0 answers
89 views

'P.V.' marking on 1940's electrolytic capacitors

I am replacing the paper and wax capacitors in a tube radio of 1949 vintage. Puzzled by the initials P.V. where I'd expect to read VAC or VDC. Can anyone explain this puzzling jargon? For some reason ...
user avatar
2 votes
1 answer
248 views

Location of AC coupling capacitors

I am trying to decide location of AC coupling capacitors between FPGA and PHY SGMII interface and datasheets of neither part has any useful information. I've read some notes, like this one from Dr. ...
user avatar
  • 39
2 votes
0 answers
172 views

Time delay in lumped element delay line

I was trying to analyse a lumped element-delay line by changing the frequency and measuring \$ V_{in}\$ , as shown in the graph the goal of my analysis is to find the time-delay and the attenuation ...
user avatar
2 votes
0 answers
45 views

Question about series-connected (pseudo-nonpolar) electrolytics

Another Q&A on this site ("Ceramic caps vs electrolytic. What are the tangible differences in use?") contains good information on capacitors in general, including parameters I wasn't ...
user avatar
2 votes
0 answers
125 views

Multisim : Wrong Output for 1 way traffic light using 555 timers

I made a curcuit using the given diagram in Multisim but my output is of the order Green->Yellow->Green->(Yellow and Red) . Pls tell what should I do to get the output of the order Green->...
user avatar
2 votes
0 answers
87 views

Is capacitor voltage coefficient a function of frequency?

I have learned that the value of capacitance in a capacitor can vary slightly compared to nominal based on the voltage across it. This is called voltage coefficient of capacitance (VCC) It is actually ...
user avatar
2 votes
0 answers
66 views

How does this timer 555 and transistor circuit work?

Is this the way this circuit works ? If vref = 5v on the pin #5, then Vthreshold = 5v, and Vtrigger = 2.5v With Vthreshold = 5v, if voltage on pin #6 Vp6 > 5v, then Vp3 is Vo = 0 With Vtrigger = ...
user avatar
  • 115
2 votes
0 answers
349 views

ESD Capacitor Calculation, 330Ohm Series Resistor and ESD Clamp Voltage

I have a input power filter circuit. It has ESD Protection capacitors which help to protect the downstream circuit from ESD Pulses. ESD Capacitors Specifications : C0001, C0002, C0003, C0004 = 47nF, ...
user avatar
  • 2,446
2 votes
0 answers
53 views

What are the most common causes for a surface mount MLCC to crack?

What are the most common causes for a surface mount MLCC to crack? I just want to learn everything there is to know about the HOT MLCC problem
user avatar
2 votes
0 answers
59 views

Design considerations for large ratio step-down transformation

What are the design considerations for a system in which a high voltage and current DC soliton pulse (approximately 50kJ at 45kV over 100ms) from a capacitor bank or PFN must be stepped down to a low ...
user avatar
2 votes
1 answer
97 views

Powering buck converter using charged capacitor

Is it possible to design a buck converter using a charged capacitor to get regulated voltage output? When the capacitor voltage falls below some threshold value the inductor should be able to provide ...
user avatar
  • 35
2 votes
1 answer
377 views

Laplace tranfsorm of capacitor functions and initial conditions

I may be asking something trivial, but unfortunately, I could not find an answer so far. Suppose an AC circuit. The voltage of the capacitor is given by $$v_C(t)=Q(t)/C = 1/C [ \int_0^t i_C(τ)dτ + v_C(...
user avatar
  • 363
2 votes
2 answers
856 views

How to estimate the voltage gain, Input impedance, current gain, power gain, and output impedance for the amplifier in the fig?

β of the BJT is 100 and from dc analysis it is found that the quiescent point is ICQ=4.12mA and VCE = 6.72V. If the emitter resistor RE is subdivided into RE1=100 Ω and RE2=900 Ω, with bypass ...
user avatar
2 votes
0 answers
1k views

Multimeter not reading capacitance accurately?

I am trying to measure new electrolytic capacitors before they go into my guitar amp to make sure that they are up to spec. I'm using a Morris #57044 multimeter, which has an autoranging capacitance ...
user avatar
2 votes
0 answers
132 views

Understanding RLC series circuit fed with a square wave

I'm simulating a RLC series circuit fed with a 60Hz 3.3V square wave coming from a microcontroller. The inductor series resistor is 100 ohms, so the total R= 110 ohms. According to the simulation, the ...
user avatar
2 votes
0 answers
1k views

Supercapacitor spot welder - which capacitors to use?

I built a spot welder using a big transformer (approximately 4kW from an old welding machine) but I now need to build a spot welder with more power (more current.) The current spot welder works great ...
user avatar
2 votes
1 answer
108 views

changing 2000 honda civic domelight from incandescent bulb to LED panel- smoothing out PWM "dimming" with capacitor circuit

My 2000 honda civic has an incandescent dome light that has PWM controlled "dimming". It takes a period of about 6 or 7 seconds when the domelight goes from full bright (not pulsed) to a pulsed duty ...
user avatar
2 votes
0 answers
108 views

Capacitor GND to GND on Magnetic Sensor

What is the purpose of this capacitor placement ? Why is it placed like that near Magnetic Sensor ?
user avatar
  • 129
2 votes
0 answers
93 views

How to remove DC power supply noise while load is active?

I'm using a breadboard power supply to power up two STM32F103, two Hall flow sensors, one IC555, and one 16x2 LCD with backlight. While everything is connected I have alot of noise in the system which ...
user avatar
2 votes
0 answers
117 views

Discharging high voltage and capacitance capacitor?

I need to discharge a 4.4mF (millifarads) capacitor storing 1200V in about 5 seconds. I did the t=R*C' and got a resistance value of approximately 227ohms. I did a ...
user avatar
  • 31
2 votes
0 answers
67 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 ...
user avatar
2 votes
0 answers
94 views

How to control charge on a high-voltage capacitor after voltage multiplier?

Can anyone think of an electronic way to control the charge on a high-voltage capacitor that is fed by a multi-stage voltage multiplier? I can control the charge on the way up by controlling the ...
user avatar
  • 121
2 votes
0 answers
3k views

Finding voltage across capacitor in series and parallel

Here's my circuit: simulate this circuit – Schematic created using CircuitLab I want to find the voltage over the 20uF capacitor; however, what I come up with is 50V which does not seem ...
user avatar
  • 279
2 votes
0 answers
142 views

design audio amplifier circuit

I wish to design audio amplifier circuit. Hear I use two stage of amplifiers. 1st stage amplifies 100mv to 1.2V peak @ 2KHz. Q1. When I change the frequency to 50Hz output becomes to 210mv peak ...
user avatar
  • 21
2 votes
0 answers
321 views

Using an automotive stereo capacitor for other uses

I am looking into using a capacitor to buffer voltage drops for a 12V solar power system. Since it seems I need a pretty big Farad number to give at least half a second of buffer time for my load, I ...
user avatar
2 votes
0 answers
1k views

Calculation for the Boot Strap capacitor

For design of a synchronous buck converter (which would be used to charge the battery) which would be driven by Micro-controller's PWM output, i selected the IRLB8748 NMOS Power transistors (for both ...
user avatar
  • 533
2 votes
0 answers
1k views

Calculating signal attenuation for AC?

So we've got this; simulate this circuit – Schematic created using CircuitLab Which I've been told is equivalent to the sum of it's Coutputs to an AC signal; simulate this circuit So then; $...
user avatar
  • 593
2 votes
0 answers
308 views

Formulas for Integral Components

Formulas for Integral Components: I am looking for "simple" approximative formulas for integral components. In particular for: A grounded interdigital capacitor (i.e. above a ground plane and with ...
user avatar
  • 4,901
2 votes
1 answer
249 views

Cascade of 555 timer with Control Voltage not triggering

Hi I'm currently working on a cascade 555 circuit, both operating in the monostable mode. I also want to be able to control the pulse width with a voltage so am using applying 0-5v to the ctrl pin (...
user avatar
  • 19
1 vote
0 answers
43 views

Why is the ACS712 VIOUT more stable with a current limiting resistor?

Below is my circuit for an ACS712 that is connected to a relay that joins to s capacitor bank: In the diagram I using two 5V power supply, one for relay module and one for (PIC,voltage reference,...
user avatar
  • 511
1 vote
1 answer
45 views

Why are there two different charges on a patch antenna? How are these charge distributions formed?

If we apply an AC signal to a capacitor, we can see only one type of charge on an individual plate. If we apply an AC signal to a patch antenna, there are two different charge distributions on the ...
user avatar
1 vote
2 answers
59 views

Why does the zcd square wave look distorted?

I have connected a capacitor to do some power factor correction on a load. After I connected the capacitor parallel to load, I checked the zero cross detection waveform, which is getting input signal ...
user avatar
  • 511
1 vote
0 answers
37 views

Tantalum Capacitor At Cold Temperatures

What could happen to a solid tantalum capacitor that operates below the lower temperature range defined by the manufacturer (-55C)? From my understanding, there would be a performance issue with ...
user avatar
  • 11
1 vote
0 answers
37 views

Boost converter design. Current issue

Currently trying to make a boost converter working at a frequency of 100kHz. For the design, I used the equations shown in https://www.ti.com/lit/an/slva372c/slva372c.pdf , my requirements for the ...
user avatar
  • 11
1 vote
0 answers
62 views

Is it possible to force charges into one plate of a capacitor?

As we know, a capacitor stores energy, but the net amount of charge in it doesn't change. If an electron enters one plate, another leaves the other plate. If the other plate is floating, the entering ...
user avatar
1 vote
1 answer
66 views

Charging of capacitor

Why Ca takes twice the time to charge as compare to Cx? In following diagram there are two capacitors Cx and Ca, which are going to be charged in steady state. Now I know the method to calculate pole ...
user avatar
1 vote
0 answers
33 views

Problem modeling capacitor bank for Three Phase Induction Motor

I'm currently working on a simulation in Simulink and I encountered a problem. I'm using a capacitor bank to improve the voltage drop at the output voltage of the motor. The problem is the capacitor ...
user avatar

1
2 3 4 5
13