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

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What parameters to look at when comparing capacitors of same value but different package size

I'm looking at a capacitor that will be used as an output cap on a buck regulator. Looking at what I think is the same exact cap from TDK (10uF, 16V, X5R) but in an 0603 and an 0805 package. Beyond ...
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2answers
89 views

Capacitor with 7805 voltage regulator

I want to get the output: 5V - 25mA from 24VDC-0.75A with IC 7805. So what should be the value of C1 and C0? I need a formula for my report. thanks in advance
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159 views

Equal rectifier capacitor

Capacity of the capacitor in circuit below is equal: What difference is there between the circuits? Which one is better? Can i made equal the capacitor with the capacitors in series? Which one is ...
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149 views

What's the name of this circuit, and how does it work?

I was reading Hack Into a Timer AC Socket and when I got to this paragraph: The design firstly have a RC buck? (not sure how to call correctly in English) circuit to step down the voltage from ...
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82 views

Slowing Down Capacitor Circuit discharge rate

I am currently trying to use a 5 Pin relay on a Motorcycle indicator circuit. The concept is I have a Daytime Running Light (DRL) that is in the same housing as the indicator. When the indicator is ...
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25 views

Can I change a design from using one polypropylene cap to four PEN/PET caps in series?

I've inherited a design for a SEPIC converter that uses a polypropylene input filter capacitor from CDE. (Specific part number 715P472516LD3.) I'm considering shifting this design to surface-mount ...
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124 views

Identifying this resistor/capacitor

I'm having trouble to identify this (presumably broken) part for replacement: It was used in a broken LED power supply, with 220-240 V AC on the input and 120-200V DC on the output. I suspect this ...
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70 views

How to the calculate the value of capacitor placed in series with transformer to avoid flux walking in a buck converter? [closed]

The dc value of current in primary increases(in -ve direction) as time passes, so I need a capacitor in series with transformer, but don't know what value capacitor should I use. filter capacitor = ...
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148 views

How to keep circuit powered when battery disconnected for short time

In an assembly, I'm using spring loaded pins to connect a battery to a circuit board. It's possible from dropping the assembly that power may become disconnected for milliseconds at a time from the ...
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3answers
105 views

How do capacitors help in smoothing potential difference from a full wave bridge rectifier?

Let me establish some facts I have understood by myself: The polarity of resistor does not change, as the current from A.C source flowing through does not change direction. The D.C potential ...
2
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1answer
103 views

How does a decoupling capacitor handle a spike (increase) in the voltage from the power supply?

From what I understand, when there is a drop in the voltage the current is drawn out of the capacitor and so the balance is maintained. But when there is an over voltage from the power supply or when ...
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197 views

Why do electrolytic capacitors have terminals of different length unlike ceramic capacitors

Electrolytic capacitors have 2 terminals of different length to indicate polarities, but ceramic capacitors have terminals of same length having no polarities. Why is there a difference between these ...
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83 views

Soldering capacitor pins

When soldering capacitors, is the order on which you solder them important? I am about to solder a project but I don't know this information For example, I can solder each pin however I like, or one ...
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109 views

Resistor required for capacitor?

I'm currently working on some simple circuits to learn about circuitry, and being a Physics major I have a pretty good grasp of the mathematics and concepts, but I'm a little confused about ...
2
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1answer
87 views

Discharging electrolytic capacitors

I believe that capacitors are safe to discharge through a short, if the voltage is not high enough to cause a dangerous spark; and the energy stored in the capacitor (E = V × Q = V² × C, if I'm not ...
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68 views

Capacitance and battery and no resistor and time

I already know the 't=RC' . But what happens if I start charging a capacitor via a same voltage battery? When will it be fully charged?
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1answer
129 views

Help on unknown part

See images below : I obtained this component from an old radio set ( possibly 90s made). It was attached to the tuning dial, so most likely it is variable capacitor I believe. It has absolutely ...
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69 views

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

Experiment 11 from Make: Electronics Hi, this'd be my first forum post. I'm really out of options here. Let me get straight to the point. I bought the book "Make: Electronics by Charles Platt" a ...
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44 views

Film capacitors, replacing with ceramics

I've been watching through hole film caps disappear. I've used a bunch of these in thermal control loops, http://www.digikey.com/product-detail/en/ECQ-E1106KF/EF1106-ND/56416 Still making 'em, but ...
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3answers
76 views

Parasitic Capacitance and AC Coupling

I was reading on Capacitive Coupling a bit and become confused when reading the Parasistic section, specifically regarding two claims. If a high-gain amplifier's output capacitively couples to ...
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1answer
91 views

Difference between capacitors of same value but different sizes

I would like to know why some capacitors have the same value (capacitance) but their sizes are different? What is different between those capacitors?
9
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2k views

I stuck a 450 V 10 µF capacitor in a 110 AC wall outlet and it exploded… why?

When I put it in the outlet it "popped" with some oily gray smoke. Honestly I thought that the voltage rating on the capacitor meant you could feed at least that much voltage through it, but clearly ...
4
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1answer
153 views

What purpose does the capacitor serve in this schematic?

I'm looking at this schematic someone did for daisy chaining a set of 74HC595's and I wanted to know why there is a capacitor put on the pin4/latch and the GND. What purpose does it serve and why is ...
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1answer
133 views

Resistor in series and capacitor in parallel to ground

Could somebody tell me why someone would need circuit like that in supply rails? I assume it is for making DC voltage smoother by parallel capacitor. However, my 24V power supply has 500mA output ...
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140 views

Solid state circuit to charge caps in parallel then discharge in series?

Do there exist a solid state design circuit to do the following: Charge multiple capacitors in parallel for a certain amount of time from a low voltage DC source, then disconnect them completely from ...
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1answer
28 views

Rated capacitor current

What does "rated current" refers to in the capacitor data sheet? Is the current that the capacitor can supply? I always assumed that it is the current that the capacitor can source. Is that correct? ...
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98 views

How to calculate the values of capacitors for 5V DC power supply

I am trying to make a power supply of 5 V; as we all know it uses a bridge circuit, then capacitors and LM7805. But I want to know how the value of capacitance is calculated. What is the formula for ...
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41 views

Why would an 8-order LPF switched capacitor has a least steep roll-off curve (max7405)?

As far for my understanding, a higher order LPF will have a steeper roll-off curve. Something like below would happen if we increase the number of order for the LPF: Normal LPF frequency response ...
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30 views

How to calculate the oscillator capacitor value for a switched capacitor (MAX7405)?

I would like to use an 8-order LPF switched capacitor: MAX7405 datasheet The cut-off frequency can be set by simply connecting an external oscillator capacitor, Cosc. I would like to design a 50Hz ...
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1answer
230 views

What is the role of the capacitor within the assembly

I have some questions regarding my assembly and especially on the role of the capacitor within the circuit. Before I added the capacitor I encountered 2 issues: when the piezo was squeezed (a ...
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1answer
110 views

Minimum number of capacitors

I require a capacitance of 2×10^-6 F in a circuit across a potential difference of 1kV . I have a large number of 1×10^-6 F is available which can each withstand a potential of 400V. Suggest a ...
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1answer
149 views

Capacitor discharge: Is gate voltage on IGBT proportional to collector?

I'm designing a capacitive discharge circuit. I'd like to get some feedback before I buy parts for testing. The output should be around 100v and thought an IGBT would work great in discharging the ...
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2answers
145 views

A cubical LC circuit

I would like to solve for currents through inductors and the voltage across capacitances of the attached circuit. I am trying to figure out a correct method to solve such circuits which could have the ...
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1answer
58 views

CX-20 Quadcopter Part

One of the ESC's on my quadcopter is missing a component. I am unsure what this component does or where to find a new part. Is it a sort of resistor?? What size? it features no markings that I can ...
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64 views

Capacitor on line with high frequency digital signal?

Capacitors act as a short for high frequency signals. If I place a capacitor on a digital 5V PWM line or perhaps a motor encoder line does the cap still act as a short to ground for the square wave ...
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157 views

Grounding a capacitor?

Noobish question. I'm trying to make a dc variable voltage power supply. I will include the schematic which I am trying to build. In the schematic there are two 1000 uf capacitors which I believe are ...
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3answers
284 views

Troubleshooting/debugging PCB

This may be an off topic question, but I'm sure many of you have the knowledge and experience to help out here. A quite complicated motherboard was flexed. The resulting symptoms include cross-talk ...
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3answers
150 views

Capacitor discharging total charge calculation

I need to estimate the total charge that flowed from the capacitor for a short duration of 2ms. I am using an ATmega128 for this. Can someone advise me if analog sample/hold in front of an ADC is ...
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1answer
50 views

Minimum voltage rating for output capacitor for use with LTC3525-5 boost voltage regulator

I'm (still) selecting parts to build a 3 to 5V boost DC-DC converter using the LTC3525-5. The board I'm planing to build is based on the typical application shown in page 11 of the aforementioned ...
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85 views

Why do we take rectangular plates in the capacitor? [closed]

We can take square, rectangular or circular plates in a capacitor. Why do we take rectangular plates in the capacitor?
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321 views

How does this mosquito zapper circuit work?

For the purpose of learning, I have tear down a small mosquito zapper racket. I am now trying to understand how the circuit is working (which goal is to produce high voltage). (yellow = ...
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0answers
68 views

Poor output efficiency of SEPIC supercap driver

I'm attempting to drive a high power led (3.6V, 700mA, nominal power 3W) from a 5.4V 3F supercapacitor via a SEPIC (see this question). While I don't have any strict design requirements, a running ...
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95 views

Dielectric can be insulators?

People say that dielectric should be an insulator so that it can decrease net electric field increasing capacitance.. My question is if the object is a insulator how does the object get polarized ...
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1answer
92 views

Why so many capacitors in design?

I was looking the schematic for programming a standalone AVR chip. I am curious why we need so many capacitors. As far as i know, i know we need one capacitor on the power supply. I don't remember ...
3
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1answer
285 views

Weakest link in lifetime of electronic circuits

I'm working on a product, a single-board computer with an expected lifetime of 10-15 years, and I'm trying to identify the correct components to focus on for this. So far electrolytic capacitors ...
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2answers
78 views

Why does my laptop adapter output nominal voltage with a broken capacitor?

My adapter broke, so I started my repairs by measuring the output voltage; it was 18V as it's supposed to! So, I figured my laptop charging cicruit was broken, but when I opened the adapter I saw the ...
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48 views

How can I use a 9v chaser board to run LED strips

a few years ago I bought an LED sequencer circuit board kit. Once assembled you can adjust the pace and the brightness with 2 POTs of up to (I think) 8 LEDs. this board runs off of a 9v battery and ...
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1answer
106 views

What can cause the capacitor to blast? [closed]

I had a problem with my air conditioner. The technician came in and fixed it. But he told me that the capacitor inside it was blast. I want to know what causes this and how to avoid it. Thanks!
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94 views

Is the value of XTAL load capacitors for ATmega328p @ 16MHz critical?

I'm going to try to assemble an MCU-based circuit using an ATmega328P-PU (Arduino UNO stripped down to essential parts as in this tutorial). I've skimmed over a lot of posts on EE.SE about load ...
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2answers
115 views

EL Wire vs EL Panel, difference in voltage and frequency needed?

I am currently researching Electroluminescent Inverters/Drivers for a project. There is many accounts that EL Wire needs a higher voltage and frequency than an EL panel or tape needs. (300vpp vs ...