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

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57 views

Question with solving for complex power, S, for each component

simulate this circuit – Schematic created using CircuitLab Hi! So I have a couple questions that I have already tried to solve that I think I am going in a little bit of the wrong ...
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2answers
110 views

Why the v-t and i-t curves for capacitor are exponential curve?

If we plot and compare v-t or I-t curves with actual exponential curve we can see that they are same, but why? Is there any proof? From the equation we can see that e is creating bridge between ...
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3answers
193 views

What prevents abrupt voltage change in a circuit with a capacitor?

Let's say we have a simple circuit consisting of a power supply and a resistor, and currently the input voltage is 0V. We now apply a voltage of 5V to the circuit (like a step increase - ...
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50 views

Repair automatic perfume dispenser [on hold]

I'm a total newbie on electronics. All I'm able to do is just connecting broken cable here and there :p So this might be dumb question, but I hope it' still the right place to ask this question Now ...
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2answers
62 views

Understanding a tuner Circuit with a reverse biased diode

This is a circuit extracted from the book "Electronic Circuits Analysis" by Phillip Cotler. simulate this circuit – Schematic created using CircuitLab The potentiometer R1 can be ...
14
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3answers
1k views

Remind me, what operation could cause the inductor or the capacitor to explode?

In really early days of electronic school, the teacher used to say something about not unplug power too quickly at an inductor or capacitor and we were used to slowly turn the voltage generator from a ...
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1answer
61 views

What does the feedback capacitor do in Right-Leg-Driver?

It so happens I have seen some people mention about connect a feedback capacitor across the opamp for RLD would improve something better. Can someone capable to explain about the use of the ...
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2answers
106 views

How to select value of resistor to dicharge a capacitor? [duplicate]

How to set the value of bleeder resistor to dicharge 10kV capacitor, which has capacitance value of \$5\mu\$F?
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2answers
152 views

Learning transistor based circuits

simulate this circuit – Schematic created using CircuitLab In one of our electronic circuit tests, this question was asked: What is the output voltage of given circuit? This circuit ...
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100 views

Switching high current and high voltage for coilgun

I am building a multi-stage coilgun and need to be able to electrically switch 450V and over 100A somehow (virtually shorting large capacitor bank)... I've tried using IGBTs but fried them. I also ...
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1k views

AC to DC without transformer. How does this thing work?

I disassembled a Chinese-made flashlight and found they use just capacitors to bring down the voltage instead of a transformer. They are using it to charge small lead-acid battery. My question is how ...
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139 views

Can someone tell me what this thing is?

More images are here: Numbers are: 500B - On the back 6800 +5% 80 - on the front
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1answer
119 views

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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99 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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160 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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2answers
156 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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86 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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0answers
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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3answers
127 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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1answer
75 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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3answers
155 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
108 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
112 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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199 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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85 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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111 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 ...
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1answer
88 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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1answer
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
132 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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1answer
84 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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1answer
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
79 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
120 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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1answer
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 ...
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1answer
156 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
136 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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3answers
142 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
30 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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1answer
113 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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2answers
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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1answer
31 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
232 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
112 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 ...
0
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1answer
150 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
147 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
69 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 ...
0
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3answers
66 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 ...
0
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3answers
161 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 ...
5
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3answers
293 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
155 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 ...