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

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56 views

Best elements for downhole and high temperature circuits

I want to design a data-logger with PIC MCUs. This data-logger is going to work in chamber in the oil wells in the depth o 500 meters. and it is going to record temperature and pressure for 20 hours. ...
-7
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0answers
50 views

Creating a stunning device that causes no harm [on hold]

My son is hard to get up in the morning, so as a gag gift I wanted to make a low voltage low amperage stunning device to tease him with, but I don't want to hurt him. What size battery and capacitor ...
2
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1answer
106 views

Why is the capacitance changing while measuring?

I have 2 different 100nF capacitors. Let's call them A and B. My dad told me that B is "better" than A. I've tried measuring their capacitance using a Metex multimeter which has the option of ...
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1answer
75 views

Controlled charging of a capacitor

I put together the following circuit that creates a single pulse of a fixed width when switch S1 is pressed. The basic idea is simple. A HIGH at the Q1 base will turn ON Q3, discharging the C2 cap. ...
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1answer
51 views

ACS758KCB Wiring Diagram

I am using the ACS758KCB Hall Effect sensor for a project. On the front page of the Datasheet it list a .1uF capacitor between Vcc and GND, in addition it lists a capacitor, Cf, between GND and ...
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1answer
65 views

Why don't we use capacitors containing multiple kinds of dielectric in a single package?

I know that it is common in DC regulators to use both a high capacitance electrolytic capacitor and a low capacitance ceramic capacitor in a parallel, in order to maintain sufficent capacitance over a ...
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4answers
61 views

voltage and current after closing the switch

In this circuit, the switch has been open for a long time that is the 2F capacitance is full. Now we close the switch. what is the equation of the current and voltage of the 2F capacitance after ...
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1answer
60 views

Understanding capacitor usage in the Sparkfun arduino [duplicate]

In the schematic for the Sparkfun Arduino mini pro 3.3v https://cdn.sparkfun.com/datasheets/Dev/Arduino/Boards/Arduino-Pro-Mini-v14.pdf there's a 0.1uF capacitor (C3) just left of the atmega ground ...
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1answer
57 views

switch mode power supply capacitors

If I am laying out two switch mode power supplies right next to one another from the same supply(24V), one is switching to 5V and the other to 12V then do I need both of the input capacitors? Thanks
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0answers
66 views

Capacitor weird behaviour when charged with high current

I put a 1 ohm resistor to charge a 100uF polar capacitor in PROTEUS simulation and the charging doesn't work, it keeps charging and discharging continuously. circuit voltage is 12V It works well with ...
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1answer
68 views

Measuring the capacity of a capacitor with arduino?

I'm preparing for a little Arduino project that our teacher announced that will most likely be a discharge voltage measurement of a capacitor with some curve fitting in Excel. So my goal is get the ...
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1answer
57 views

Final voltage of two parallel (switched) capacitors

I am trying to obtain a resistance-circuit equivalent to a switched-capacitor circuit. It is the first stage of a ladder filter. simulate this circuit – Schematic created using CircuitLab ...
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2answers
71 views

How to select capacitor for my rectifier circuit

I had designed a rectifier circuit, in that I don't know how to choose capacitor. for example if I'm get in input supply as 9 V, now I want change it for 10 V, then how should I choose capacitor.
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3answers
628 views

Is it bad to connect multiple electrolytic smoothing capacitors in parallel?

I'm making a power supply using a transformer and bridge rectifier, and I'm wondering whether it is a bad idea to put multiple (5) capacitors in parallel for smoothing. The output should be capable ...
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1answer
134 views

Is this circuit block diagram correct?

I plan to build a flashlight powered by 360F 2.7V super capacitor (proposed to be charged to max 2.5V and discharged to min voltage of around 0.6V to increase capacitor life). The EMF generated by the ...
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1answer
60 views

Calculating the voltage out of this particular cap coupled circuit

Before I get to my question, I'll just go over the input and output of the circuit from what I "know". The base of the BJT gets a 20 microsecond pulse that puts the bjt well into saturation and "VOUT" ...
2
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2answers
219 views

Capacitor/resistor effect on audio signal

I have a pair of 20 years old electrostatic speakers that have an analog first order high-pass filter before the electrostatic panels, so there is a capacitor in the audio signal path. The original ...
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2answers
298 views

I just blew a capacitor. Now what?

We worked two years on and off on this project at my friend's place. Finally we finish, I take it home. There's a power supply unit but it can't be connected directly to mains, it expects some lower ...
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0answers
28 views

crystal oscillator and CSTRAY

Let assume I'm using atmega8-16pu and I want to connect a 16MHZ crystal oscillator with 20pF load capacitance. Now I need two capacitor connected to GND and the chip ( XTAL1/XTAL2 ) itself so I have ...
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1answer
29 views

Determine the correct capacitors value

what the right way to determine the correct capacitors value needed for a avr-chip with a crystal oscillator? Let say the crystal's load capacitance is: 20pF and i want to use: atmega8-16pu what ...
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1answer
51 views

Natural discharging duration of an unpluged capacitor

Can natural discharging period of a charged capacitor be detected by a certain formula? If it is related to initial voltage and the internal parasite resistance, what are the factors affecting this ...
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2answers
62 views

Measure capacitance with OPA604 and this circuit

I am following this circuit: to measure the capacitance. The opamp is OPA604 with supply voltage +-5V, Cx and Cf is 5pF, Rf is 10Mohm, the diode is 1N4007 and the output capacitor is 1nF. I also ...
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2answers
74 views

Why we need 100n cap parallel to IC power supply [duplicate]

I've seen this in many schematics, I also do it myself, but I don't really know why it's needed. I've also noticed that on RGB led strips, there's tiny 100nf caps, too. Why is it needed? Also, if ...
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1answer
182 views

What is the purpose of the capacitor in this transformer circuit?

I a audio DAC output stage I have seen the following circuit. It's function is to convert an balanced signal to an unbalanced signal. IN+ and IN- are differential outputs that are biased at 2.5V. ...
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1answer
42 views

Breadboarding digital mixer: deriving Vref from Vdda, and capacitor between Vdda and Vssa?

I am assembling a digital audio mixer from an old IC I have on my workbench. And I am reading the data sheet and trying to make sense of a note that describes the Vref pin (reference voltage). The ...
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1answer
32 views

Capacitor and discharger selection for pulse discharging

I want a 100 Joule pulse in 350 micro seconds. I have 1000V nbu 1012 capacitor discharge circuit . In datasheet, Max. average power is 3000 W(page 8), however I need 100/350us= 285kW instantaneous ...
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2answers
178 views

Determining the voltage and charges across each capacitor

Since someone edited my question and asked me to post a new question instead with the edits I did, so here is the new schematic for this question: Can someone help me find the voltage and charge ...
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3answers
47 views
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1answer
99 views

RC Filter Circuit Question

Given the image below, we know that the second filter circuit is a Passive Low Pass Filter circuit. I'm assuming it is still a Passive Low Pass Filter with a different corner frequency. Am I correct? ...
2
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1answer
131 views

Trouble with first part of Experiment 11 (Make: Electronics) when using multimeter

Here is my circuit. It works well, as described in a book, but I want to understand it better, so I want to check voltage on capacitor. But when I do it, LED doesn't blink and voltage goes up to 4V. ...
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2answers
80 views

Paralel RC time constant [closed]

In parallel RC circuit, what is the behavior of current of capacitor C1? What is the time constant?
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1answer
63 views

All capacitors leaking on Emotiva PSU? [closed]

I've just opened the top of my XPA-2 amplifier and had a huge surprise: it seems like almost ALL of the caps are leaking from the bottom. Not just the main PSU caps, but smaller ones on PSU PCB and ...
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3answers
98 views

why capacitance depends upon frequency physically irrespective of mathematical fact?

Sir,I know that when f=0 capacitive reactance will be infinity according to mathematical formula and thats why capacitor blocks dc.But what is its physical significance?I mean why capacitor blocks dc ...
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2answers
139 views

what frequencies do caps filter?

I've been trying to find out what frequencies get filtered out by which type and capacity capacitors, but cannot find simple rules that say "type X, cap Y filters xxx (k/M)Hz - yyy (k/M)Hz". Yet ...
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0answers
41 views

Decoding ceramic capactior

I've done some searching and found how to decode 3 digit markings, but I'm unsure about 4 digits. I have a ceramic capacitor marked: k2ORu - 9634 I gather that the K is the tolerance, not sure about ...
2
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1answer
109 views

Hold-up time calculation with high capacity MLCCs

I am designing a linear voltage regulator for 5V (from 30V) at 10mA for a low cost application. Everything works out so far, but I need around 10ms hold-up time in case of an input voltage failure. ...
0
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2answers
130 views

Finding the voltage and charge across capacitor

Can someone help me find the voltage and charge across each of the capacitors? This is not just a simple/ parallel circuit so I am having a problem in formulating the right equation on how to find the ...
2
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1answer
64 views

Op-Amp difference amplifier low-pass filter

I have the following (summing, single supply) difference amplifier circuit: How can I extend this circuit to a 1st or 2nd order low pass filter, with a corner frequency at about 20kHz.
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0answers
28 views

Cycling peak load trips genset

I have an application where a cycling peak load from a 40hp motor is regularly tripping a 65Kw genset. Here are the details of the configuration: 65Kw Genset powered by a natural gas engine 40hp ...
2
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1answer
63 views

Calculating Op-amp supply bypass caps values

Either I suck at searching or there is not a lot information about calculating values of bypass caps for opamps(I found a bunch on the topic in general). The question is, what it says in the title, ...
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2answers
56 views

Reverse biased capacitor on IC input pin

I am looking at the test circuits on the data sheet for the AN6884 VU meter IC, and I cannot understand the connection to pin 8 in the following diagram: Pin 8 accepts a positive input voltage. The ...
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2answers
65 views

Voltage across a capacitor variable of integration

I understand that something that is charged with one coulomb and has a potential difference of one volt across it will have a capacitance of one farad. \$C = \frac{q}{V}\$. I get that because current ...
3
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2answers
73 views

Replacing Crystal Oscillator with DDS.

In a circuit like this, can the crystal oscillator be replaced with a DDS such as a AD9850? If so can it just be dropped in or would other components have to be changed? Second question, how ...
1
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1answer
60 views

How does one calculate the voltage ratio V+/Vo for this circuit?

I can understand the first case above, that seems simple as I can simply measure across the ground and V+, but I am getting very confused for the second case. Is the capacitor and the resistor in ...
2
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3answers
99 views

How capacitors connected in series are affecting the total capacitance of the network, since there is no actual flow of electricity due to dielectric?

Can someone explain how is it possible to calculate the value of caps connected in series? I am not asking about the maths, I just try to understand how can such a network be created since there is ...
4
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1answer
152 views

Maximizing force of magnetic mass accelerator

I am planning to build a coil gun to fire small neodymium magnets out of a pipe. For this I am planning to use a large 400 Farad 2.7 Volt capacitor. I am wondering how many coils of wire I should ...
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2answers
213 views

How to properly discharge a high voltage capacitor?

I have recently blown a capacitor on my home made emp. I have got the perfect replacement which is an electrolytic capacitor, 330v, 140 micro farads. I have charged it but I want to learn how to ...
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2answers
56 views

pulse capacitors [duplicate]

I've got a Polypropylene 630V capacitor. Wikipedia says this about polypropylene in capacitors: "Very thin sheets of polypropylene are used as a dielectric within certain high-performance pulse and ...
1
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1answer
190 views

How can I fix a “singing” capacitor

There is a 332 1kv ceramic disk capacitor in a battery charger that I use on my desk. The capacitor emits a very high frequency and headache-inducing "singing" noise. I understand that this is normal ...
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0answers
73 views

capacitor value to add delay in circuit

I am using a relay to turn on/off a 12V motor. I wanted to add a delay in the circuit by adding a capacitor across the relay. I wanted to know what value of capacitor should I use to introduce a delay ...