Questions tagged [capacitor]
A fundamental electronic component that stores energy in an electric field, commonly used in filtering applications.
729
questions with no upvoted or accepted answers
3
votes
0
answers
144
views
Found a bizarre looking capacitor
I found these capacitors from a broken test equipment in my lab. I guess these are capacitors since the component label starts with 'c'. But I'm not 100% sure what they are exactly. I've also noticed ...
- 587
3
votes
0
answers
85
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 ...
- 131
3
votes
1
answer
158
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 ...
- 121
3
votes
0
answers
246
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 ...
- 131
3
votes
0
answers
127
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 ...
- 41
3
votes
0
answers
72
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 ...
3
votes
0
answers
835
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 ...
- 1,060
3
votes
0
answers
314
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 ...
- 5,189
3
votes
1
answer
337
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 ...
- 31
2
votes
1
answer
78
views
Output Capacitor Design for a Multiphase Buck Converter
According to this application note from Texas Instruments, in the design of the output filter for a multiphase buck converter there are basically two ways of choosing the output capacitor. The first ...
2
votes
0
answers
58
views
Crystal Load capacitors & ESR
In the KSZ8863 datasheet, the crystal specification is given (table 9-3), page 85.
Here the ESR is specified to 40ohms with no minimum nor maximum marking.
Load capacitance is specified to a max of ...
user220456
2
votes
1
answer
129
views
Capacitor discharging in a low power active-high pulse circuit
Team, Thanks as ever for your wonderful support. Long time listener, first time caller.
I trying to make a low power active-high pulse (4-8sec RTC interrupt) when a switch is pulled to ground for up ...
- 33
2
votes
0
answers
70
views
Connecting digital ground and chassis ground
I have an Ethernet connector whose chassis or shield ground I need to connect to the digital ground. I read that it is a practice that is followed in many designs.
My questions:
Why should they be ...
user220456
2
votes
1
answer
116
views
What is the function of the capacitors and MOV on the outlet receptacle of this isolation transformer?
I recently purchase a used Tripp-Lite IS250 isolation transformer off of eBay. Here is the datasheet. It's a fairly open secret that these are not true isolation transformers suitable for a tech bench,...
- 314
2
votes
1
answer
108
views
Do I need decoupling capacitors in this schematic?
I just read about 'decoupling capacitors' to stabilize the voltage. I have some small voltage drops on this schematic when I made it into a PCB.
Can capacitors would solve the problem?
If yes, where ...
- 89
2
votes
1
answer
93
views
Capacitance on the output of a voltage converter
In a project I have a TLV62065 5 to 3.3 V voltage converter. I need to take the maximum amount of current, i.e. 2 A. The maximum output capacity for the converter is 22 μF.
The suggested capacitance ...
- 51
2
votes
0
answers
176
views
How to measure leakage current through a capacitor in a simulation?
I am trying to design a new capacitor and then measure the leakage current through it. First, I want to find a way to measure the leakage current through a capacitor. I am using a PDK which has real ...
- 404
2
votes
0
answers
189
views
White residue on circuit board
What is this white powder on my induction cooker hob? Is is metal salt? The capacitor recently melted
- 21
2
votes
1
answer
69
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 ...
2
votes
0
answers
301
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 ...
- 207
2
votes
1
answer
639
views
Converting a car receiver CD player to AUX using source selector IC
I have old Pioneer DEH-2800MPB car receiver (from 2005) and I would like to convert CD source to AUX input. I found the PML014A chip in the diagram, where the audio signal from the FM tuner and CD ...
- 21
2
votes
0
answers
286
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.
...
- 3,513
2
votes
1
answer
73
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 ...
- 21
2
votes
0
answers
2k
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 ...
2
votes
0
answers
154
views
Sample and hold & analog shift register
I have this circuit (see first picture.) it's an analog shift register where instead LF386 I use LF398H. This circuit must provide an hyperchaotic behavior for initial conditions x1(0) = l, x2(O) = O....
- 31
2
votes
0
answers
78
views
Calculating forced response in RC circuit
In one my assignment questions, I need to find voltage across a capacitor. This is the diagram given:
And the conditions given are:
1- Switches A and B are in perfect sync, and when A opens, B closes ...
- 121
2
votes
0
answers
80
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 ...
- 123
2
votes
0
answers
121
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 ...
- 629
2
votes
0
answers
284
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 ...
- 21
2
votes
0
answers
54
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 ...
- 31
2
votes
0
answers
317
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->...
2
votes
0
answers
133
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 ...
2
votes
0
answers
75
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 = ...
- 215
2
votes
0
answers
234
views
SMPS powered DC motor inrush current problem
I stumbled upon a problem when connecting a DC motor to a SMPS. It's a 20W AC/DC converter with an 12V output that powers some 12V DC motors the processor and some LEDs. I needed to speed up the most ...
- 43
2
votes
0
answers
705
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, ...
user220456
2
votes
0
answers
55
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
2
votes
0
answers
66
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 ...
- 31
2
votes
1
answer
130
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 ...
- 35
2
votes
1
answer
2k
views
Laplace transform 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(...
- 391
2
votes
2
answers
2k
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 ...
2
votes
0
answers
3k
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 ...
- 21
2
votes
0
answers
215
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 ...
user115094
2
votes
0
answers
2k
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 ...
2
votes
1
answer
124
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 ...
- 21
2
votes
0
answers
152
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 ?
- 129
2
votes
0
answers
128
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 ...
2
votes
0
answers
110
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 ...
- 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 ...
- 301
2
votes
0
answers
71
views
Is using a capacitor to transfer a 0.1 V differential between voltage levels reasonable?
The temperature of a terminal at -600 V and 500°C needs to be measured. I am using a thermocouple for this, and to achieve the most accurate reading the couple must be physically connected to the -600 ...
- 906
2
votes
0
answers
186
views
How to convert Ripple Current spec to ESR?
It used to be that vendors like Digikey gave a cap's ESR value and not ripple current. Nowadays, it seems more report only ripple current and not ESR. What gives with that?
So what are we supposed to ...
- 16.1k