# Questions tagged [capacitor]

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

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345 views

### How does this tone generator circuit work?

I'm an electronics newbie who just started experimenting with the Snap Circuits style kit and I came across this high-frequency oscillator circuit. When I put it together, I hear a middle to high ...
89 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 ...
108 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 ...
163 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 ...
642 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 ...
321 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 ...
127 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. ...
58 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 ...
249 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 ...
61 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 ...
83 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 ...
177 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. ...
116 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 ...
39 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 ...
81 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->...
66 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 ...
57 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 = ...
211 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, ...
51 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
58 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 ...
81 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 ...
169 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(...
537 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 ...
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 ...
110 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 ...
303 views

### Pi filter with resonance in power supplies

I have recently read in older book (I don’t have it on me, it was from at least 90’s) about LC filter with resonance in chapter about filters in power supplies. It looks like regular pi LC filter but ...
100 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 ...
89 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 ?
80 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 ...
113 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 ...
64 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 ...
91 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 ...
2k 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 ...
3k views

### Single Phase Induction Motor Wiring help

I have purchased a Single Phase Induction Motor that runs anti-clockwise, I require it to run clockwise however I am unable to figure how to change the wiring to do this, any help would be appreciated....
136 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 ...
413 views

### Ceramic capacitor in High voltage DC link

In motor drive application the high voltage dc link between the rectifier and the inverter usually have: a bank of aluminium electrolytic capacitor a film capacitor near the inverter Is there a ...
264 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 ...
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 ...
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; \$...
306 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 ...
192 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 (...
32 views

### STM32G030 BOOT0 pin - SWCLK

I designed a board with an STM32G030C8T6 MCU and some peripherals. The board is working just fine, regarding the functionalities, but I have some issues with flashing. So, the first "strange"...
37 views

### Generation of electrostatic induction

I need to generate a 500 volt electrostatic charge. How can I do this? I don't have a Van de Graaff generator. What are some practical suggestions? Basically I want to do an experiment in which I need ...
36 views

### ATtiny2313 external 2 MHz crystal

I would like to run my ATtiny2313 from an external 2 MHz crystal, but I'm unsure how. I have seen images and examples where there are capacitors connected to ground after the crystal. Like this: But ...
63 views

### What would the output waveform be in each of these cases?

In the second picture, the source is a step function from 0 to 1V. I feel like I solved them, but I am not convinced that my understanding is air-tight. Any help is appreciated. Edit: Adding my ...
61 views

### 2nd Order Circuit

just want to check whether am i doing correctly? How do I know when should I find Voltage ODE and when should I find current ODE? Thank You Update: Vc(0) shld be zero.
101 views

### Prevent capacitor discharge after it was charged using a microcontroller

I want to use a micro-controller (like an Arduino) to: Charge an external capacitor Measure voltage across the capacitor Capacitor discharge rate as low as possible. Capacitor discharge rate while ...
64 views

### Stop 'bouncing' input from float sensor

I'm trying to resolve an electro-mechanical issue to do with a water fill solenoid, that is triggered by a float valve. The problem is as the water approaches full, the float bounces causing the ...