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Questions tagged [capacitor]

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

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21 views

Should we use amplifier for higher watt speakers?

I'm very beginner at designing amplifier and maybe more. Is this true for designing "The more watt the larger Capacitor we need for the amplifier design " ?
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1answer
113 views

Full bridge driver capacitor ringing problem

This is my first time designing a full bridge driver. I am experiencing problems with ringing on the output. I have made a pcb for it. This is a picture of the top side of the board. Backside Input ...
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3answers
1k views

Is it safe to use series polarized capacitors to form non-polarized capacitors to be used for higher rated voltage?

simulate this circuit – Schematic created using CircuitLab It is known that we can use series capacitors to increase rated voltage. But I want to know how far we can push this feature to? ...
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2answers
2k views

Capacitor Bank Rating

I need to know why capacitor banks are rated in KVAr rather than Farads? Suppose I have one capacitor bank of 10kVAr which is for a rated voltage of 400V. Will this bank provide the same reactive ...
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1answer
85 views

X5R capacitor derating and highpass filters

X5R capacitors derate to about roughly 85% when DC voltage is applied, from what I have been told. Does this have an effect on high pass filters, even though HF filters off DC (0Hz)? If I wanted to ...
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1answer
53 views

Need help determining smoothing capacitor(s) for rectifier

I am making a rectifier for a single N-Scale train building. It takes DC, but the train controller gives out 19VAC. I have 4 1N4001s and some capacitors, but probably not the right size/uf. I only ...
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1answer
45 views

Supercapacitor for Wind Energy

I am building this wind turbine project and the problem I am facing is the irregular winds that does not keep the inverters running continuously. I initially decided to solve this problem by employing ...
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1answer
568 views

How to power a fan from capacitor after main power is down?

I power a 12V 0,84 W fan from a 5V power supply through MT3608 step-up converter. I would like the fan to work for about 5 seconds more after main power is down. Is it possible to do it using a ...
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0answers
49 views

Choosing capacitors “series”

I am about to do a simple recap on video board and deflection board for a CRT monitor from the 2000's. I ordered the capacitors in but have realized that I ordered low impedance series on all of ...
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1answer
158 views

Capacitance change value [on hold]

I have a problem with the capacitance value change in bus with some wires when I touch it by hand. I don't know if the change is because of the leakage current and how to solve this problem to have ...
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3answers
127 views

Why does a capacitor not discharge in the same cycle it is charging in a clamper circuit?

As far as I understand, in an AC circuit, a capacitor is supposed to charge as the voltage is increasing, and as soon as the voltage starts decreasing, the capacitor starts to discharge (Since it will ...
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2answers
114 views

Was my circuit victim of capacitor self-resonance?

In order to generate a short pulse off a permanent constant current signal, I made this circuit. It works well except that it created a very high frequency ripple which wreaked havoc all over the ...
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1answer
47 views

Can this capacitor move this solenoid kicker

I'm buying this solenoid: The data are: Voltage: 12V DC Current: 8A I need to build a kicker: push a button, capacitor charge, when is charged the solenoid kick an object. I want to do it with ...
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3answers
3k views

Precision Power Supply / Elektor, December, 1982

Since this PSU was published by Elektor I assume that some of you might heard or read about this project. http://www.retro.co.za/zs1ke/projects/PrecisionPowerSupply/PrecisionPSU-Elektor-Dec-1982.pdf ...
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3answers
143 views

Simplest shift register test circuit - clock

I'm looking for the simplest way to test the operation of a 74HC595 shift register without complex circuitry. Currently (on a breadboard) I have a 47K SIP resistor in a pull-up fashion connected to ...
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1answer
63 views

Will capacitance decrease of MLCCs help me pass the test?

The product I currently design (a fork sensor) has a metal chassis which is not connected to earth ground. Examining the product of a competitor, I see there is a large SMD capacitor between it's ...
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1answer
118 views

Using a single resistor for constant current load

I have a super capacitor (1000F) laying around and I want to measure ESR and it's capacitance. I have access to a 8V/500A power supply and various meters. If I wanted to charge/discharge the ...
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2answers
70 views

Hspice does not give correct energy consumption for a RC circuit connected to a DC supply

Here is the circuit I am trying to simulate - a RC circuit driven by a DC voltage source. I measure the output across the capacitor. Assume Voltage source is 1 V. Assume capacitor is 1fF. Case 1: ...
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5answers
373 views

Decoupling Capacitors on each VDD pin on a tiny 36/49 ball WLCSP/µBGA chip really necessary?

I've searched this and many other sources on Info on decoupling capacitor placement, but couldn't find any info specific enough to my current problem. I'm currently doing a PCB Layout for a tiny, ...
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1answer
89 views

Determine the power dissipated in W in the 5 Ω resistor [closed]

simulate this circuit – Schematic created using CircuitLab Excuse me for my really bad use of the schematic feature I just didn't know how to switch to the phasor domain. Anyway, I'm asked to ...
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0answers
18 views

Do I consider a downstream devices input capacitance when choosing the output capacitor for a switching regulator?

I am designing a circuit in which I chain together a few switching regulators. Each regulator defines specifications for capacitors to be placed on the input and the output. Do I need to consider ...
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2answers
105 views

Non-Polarized Electrolytic Capacitor Replacement

To the best of my abilities, I'm trying to repair an Atari 800XL which was sold as "non working unit". I found a new graphics chip and it's working ok. I though that, since I had it opened up, it ...
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1answer
63 views

APC Smart UPS - 2700uF 40V Capacitors

Please excuse the possibly simple question but this is all a bit new to me. I have an APC Smart UPS 1000 which has a very large/tall 2700uF 40V capacitor on the battery (24V) connector. Not knowing ...
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8answers
84k views

High Voltage Capacitor, in a low voltage system?

Quick question, is using a Capacitor rated for High Voltage (lets say 35v) in a System that lets say supplies 5v (like for LEDS.....or what have you) Dangerous? Since it can store UP to 35v, will it ...
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8answers
52k views

Why put a resistor in series with signal line?

A lot of times in circuits I see a resistor placed in series in a signal line and sometimes even in series with an MCU's VDD line. Is the intention of this to smooth out noise in the line? How is this ...
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3answers
743 views

Help on ID for SMD component (probably diode)

I recently smoked a DC motor control board and need help identifying the wounded component. before picture (H2 and sideways 3) and here it is, wounded It looks to me like a resistor SMD; but, of ...
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0answers
48 views

Suitable replacement capacitor for my induction stove?

I have an induction cook top with a failed/failing capacitor. The capacitor has the following printed on it: MKPH SH 0.3 uF +- 5% 800VAC 50/60Hz Max Temp 105 C E215893 The component has "BM" ...
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2answers
135 views

Capacitor Storage Temperature vs Rated temperature

I have a device that contains this capacitor: https://search.murata.co.jp/Ceramy/image/img/A01X/G101/ENG/GRM21BR71H104JA01-01.pdf The rated temperature range was listed as -55°C to 125°C. However, in ...
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1answer
672 views

Can anyone tell me what this component is (goes to an AC motor)?

Does anyone know what this is? What do I replace it with? This is from an old Wolf belt sander 5573 (which became the Makita 9401 I think) which was running, then just stopped. I checked the AC motor ...
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1answer
123 views

Finding total energy for RC discharged capacitor at t = ∞?

Most Rc circuits are not as severely difficult as this kind of circuit. I'm trying to solve for both the time constant and the voltage V2 across the R2 resistor, both of which will hold the necessary ...
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2answers
137 views

Capacitor Voltage during Transients

I am starting to learn transient analysis series RC which requires our own equations to be derived, but I don't understand how the voltage across the capacitor is given in the equation below from a ...
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1answer
281 views

Is C0G a synonym for NP0?

This question is in the context of a production environment where part numbers and change notices are strictly controlled, and any alternate manufacturer parts under an internal part number must be ...
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2answers
7k views

Substituting capacitors

I have a nicely-spec'd wireless router that doesn't work any more. (Sorry, I don't have a schematic, but it's an Asus RT-N16.) I popped it open and found that it has one capacitor with a bulging top....
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1answer
130 views

What are these values on this capacitor?

As you can see from the images, this capacitor needs replacement, however I do not know what the top 2 values mean. It doesn't state it's capacitance either... I assume the first value is decijoule ...
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1answer
19 views

Phototransistor and Photodiodes capacitances when some in an array sense light

I'm using phototransistors to sense low speed data (about 7 bits a second). With one phototransistor and a 300K resistor, I found my sweet spot and can transmit correct data with lazer. I find if the ...
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1answer
152 views

LC circuit with series diode (finding the linear average)

I've the following series LC circuit: Find the (linear) average of the current trough the diode. The ideal is a ideal component. The initial conditions in the circuit are equal to zero. MY ...
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4answers
3k views

Why places capacitors in front of the line to a (headphone) audio speaker?

I'm using this module based on the popular bluetooth module CSR8635 https://www.tinyosshop.com/index.php?route=product/product&product_id=875 I was wondering why, in the right-hand side of the ...
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1answer
47 views

Working of NMOS as a capacitor

I came across instances where NMOS was used as a capacitor in analog circuits. This is done by shorting the drain and source. The drain/source acts as one terminal of the capacitor while gate acts as ...
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2answers
48 views

Filter capacitors to avoid pop when hitting footswitch

This is an audio circuit question. I have two line level signals going into two DIs going into a PA. I want to craft a custom passive mute switch, sometimes when debugging feedback when performing ...
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1answer
124 views

Ignition coil HV power supply damage?

I recently built a HV power supply, as per the link (using a pencil ignition coil). However, I used a capacitor of around 5nf, which meant the supply did not work. The capacitor reduced the amps too ...
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2answers
53 views

How do I decide which which oscillation frequency and capacitors to use with a boost converter?

I'm working on a few projects where I'll be driving about 8 WS2812B LEDs on a 5V rail with an ATTiny85 (I think the whole circuit is going to draw about .5A; I'm using .75A for my calculations). I'm ...
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1answer
60 views

MC78M12 voltage regulator without bypass capacitors in a simple PCB with only analog signals

I have a very simple board, two layers, two gnd polygons, 8 analog inputs incoming from 8 potentiometers and 8 analog outputs. In the PCB are 2 resistors (R1||R2) between input and ouput. So, output ...
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1answer
70 views

Can someone help me identify what the value of this capacitor is? [duplicate]

I have an older computer and as I was pulling the graphics card my fingers slipped and I pulled this off the board... Problem is I can't find one with the same markings so I need to find a replacement....
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1answer
54 views

Does capacitor package size matter?

I'm selecting parts for this boost converter circuit: The BOM lists these devices: I'm at a hobbyist level with electronics so I can't tell when design decisions are arbitrary and when they're ...
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2answers
116 views

Why have an inductor between 2 parallel capacitors? (LED driver)

This is the driver for a LED Bulb. I don't understand why there is an inductor between the 2 capacitors C1 and C2? I understand that C1 and C2 are used to handle low frequency ripple and the noise. ...
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1answer
79 views

6 volt drop to 1.2 volts

I am working on a circuit for my deer feeder. I now have a 6 volt power source running the spinner on the feeder and it has a 6 volts solar panel recharging the battery. I made a new circuit control ...
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1answer
51 views

Measuring Output Ripple voltage in Scope

I have a DC-DC converter which converts 16V to 23V. I have an output E-Cap at the end of the converter. I need to measure the ripple voltage at the E-Cap. I am using a 300MHz scope. I connect my ...
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2answers
51 views

would like to verify a filter design I need to make for a backup camera in my truck

I am installing a backup camera in my truck. I am getting some source of electrical "noise" in the electrical system in my truck and its not allowing the backup camera to operate. Let me explain a ...
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1answer
335 views

Does a MAX485 need decoupling capacitors?

I am designing a small device with two MAX485 chips. Do they need the decoupling capacitors on the 5V power?
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0answers
34 views

Capacitance of circular parallel plate capacitors

I've been trying to solve this question for a while now , but I can't seem to get to the written solution. Question : Calculate the capacitance of a parallel capacitor having two identical conductor ...