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

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18 views

capacitor's voltage dropping instantaneously

I've got a fairly large capacitor (hundred mF's) that has a low voltage rating (10V). And, when I charge it to that value, as soon as I remove power supply (same voltage) the capacitor drops to around ...
-1
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0answers
34 views

Capacitor Timer Circuit

I understand that you can charge a capacitor in a certain amount of time depending on the resistor value you put in parallel with it. I am also told that capacitors are used in timer circuits and ...
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1answer
40 views

capacitive action in transmission lines

When two conductors separated by dielectric it acts as a capacitor,in my case tranmission lines are current carrying conductors and they are separated by dielectric material(air)and it acts as ...
-1
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0answers
56 views

I'm making a speaker with variable: Resistors, Capacitors, and Inductors. What do I need? [on hold]

I'm a total Noob at Circuits, i have no education whatsoever. But, I want to build a speaker system with the abilities of changing volume and frequency ranges. I've done a little research on the ...
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1answer
16 views

NP0 C0G X7R (Y5V?) Typical Leakage Currents?

does anyone have some "typical" values or ballpark averages for the various SMT capacitor leakages? I assume that if the leakage is dependent on the dielectric, then NP0's would be "best." But how ...
2
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2answers
347 views

A few questions about basic capacitor concepts

So say you a typical setup like in this diagram. How does current flow while the capacitors charge? To elaborate, what is the mechanic that makes capacitors mimic the functionality of a wire ...
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0answers
16 views

I wanna set a voltage from which a capacitor charges and discharges back to. How?

Ok, so I am using the capacitor characteristic exponential charge and discharge to drive a simple circuit that lights the LED gradually which in turn drives the LDR. Since this circuit is controlling ...
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1answer
21 views

Capacitor Battery Charge Circuitry

Just a forewarning I am a complete rookie when it comes to capacitors I am looking to supply a 0.5mV charge into a capacitor, then have the capacitor discharge to a battery once the accumulated ...
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0answers
27 views

what is the physical meaning of current lag voltage? [closed]

![enter image description here][1] [1]: http://i.stack.imgur.com/7lSui.gif wasffghuii
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0answers
22 views

Capacitors in Series and Power Factors

Can a series capacitor be used for power factor connection? What are the consequences of putting a capacitor in series with the load?
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2answers
67 views

Under what conditions will the following circuit work?

The following circuit that only has a single supply wire and not grounded (see below). Under what condition can this circuit be made to work (supply a small amount of rectified current, say 5mA). In ...
2
votes
1answer
97 views

30 capacitors in parallell?

I can't find any uF valued capacitor with a high Q-rating (~150) for my required frequency (~100 MHz). I need a 3 uF capacitor of this kind to realize my filter. I have found a good capacitor that ...
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1answer
34 views

Why does ceramic capacitor ESR change with frequency?

In most datasheets, I see a typical table which shows that ESR of ceramic capacitor changes with frequency. I understand that impedance of every kind of capacitor must have a minimum due to its ...
0
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1answer
39 views

how to charge a non-polar capacitor? [closed]

I got red square part from a circuit, i searched about it and found out that it's also a capacitor calling "non-poloar" capacitor. it's rating is 600v. I have charged other type of capacitors before. ...
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3answers
70 views

I want to convert 12v DC into 5v DC

I know there are lot of examples are given on internet. I have searched and I found good one. I am not professional in electronics engineering. I am Software Developer and I am trying to create a ...
-1
votes
0answers
32 views

Figure out pF values of a multi-pin variable capacitor [closed]

I've got this FM/AM tuning capacitor from an FM/AM radio: I'd wish to figure out the pF value of each pin: C1, C2, C3 and C4; i just know that the central pins are connected in common, so, then, ...
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1answer
67 views

Blocking capacitor? Driving 8 ohm .5 watt speaker with microcontroller

I'm reading Make: AVR Programming. The next project wants me to try to drive an 8 ohm speaker with a pin from the microcontroller. I'm no EE, but I do know that 8 ohms is not a lot of resistance, and ...
4
votes
3answers
114 views

Simple ADC alternative by using a capacitor and digital Arduino pin

I'd like to measure a dozen potentiometers with an Arduino UNO. Unfortunately, the UNO only has 6 analog pins, but it does have about a dozen digital pins. Could I effectively measure an analog value ...
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0answers
68 views

TVS Diodes Exploding, how can i suppress transients?

I am using a TVS diode to prevent the switching transients taking my capacitor above 75V to prevent my dc-dc converter being damaged. However the TVS is dissipating way to much power and exploding ...
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2answers
141 views

Does location of bulk storage capacitors matter?

Suppose I want to include a bulk storage capacitor in my circuit to help support a servo motor as it starts up. Does the physical location of the capacitor on the PCB matter in any practical sense? ...
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3answers
246 views

What are these electrolytic capacitors?

I am restoring a stereo amplifier circa 1985 (specifically the Technics SU-Z55). Part of that is replacing the electrolytic capacitors on the mainboard due to some audio popping and general age. There ...
0
votes
1answer
38 views

Lengthening charging time of a capacitor

Alright, so I got a circuit that charges a capacitor and I want to charge it to a fixed voltage in a longer time than than the current provided would have (as the current provided would have charged ...
0
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2answers
58 views

How to remove the static sound in an fm transmitter

Hi I have a school project and I used the schematics from this website for our FM transmitter. Its actually working but its hard to recognize the music being played because of the static, also does ...
1
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1answer
59 views

Replacing a relay by a transistor

i'm new in electronic, I made a simple circuit to control a pump it's working, but i'm really not happy of the result. I have to plug 2 power sources because if I have only one for the pump and the ...
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0answers
60 views

tunable oscillator circuit: get rid of the variable capacitor

In these days I'm doing some experiments with oscillators circuits; I've built an oscillator circuit which is tunable using a variable capacitor (the range in picofarad of this variable capacitor is ...
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1answer
65 views

Power on reset circuit for microcontrollers

In this schematic, there is a reset circuit with two pushbuttons: The button marked "warm reset" sends an active low signal to one microcontroller, while the button marked "cold reset" sends a ...
0
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1answer
70 views

What is so special about being multiples of 22, 47 and 56 for standard capacitor and resistor values? [duplicate]

Why is that special numbers instead of multiples of 10? Same goes with some resistor values of 47, 560 220 ohm ect.? Where and why is this issue originate from?
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0answers
19 views

How do I calculate Wye Delta transform for a series of capacitors?

I know that the wye delta transform for resistors can be calculated using equations that are easy to find (such as on the Wikipedia page on it). However I cannot find a good resource on how to ...
11
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3answers
1k views

Does the type of capacitors matter?

The IC ICL232 needs some capacitors. Should these capacitors be ceramic or any other type? When does the capacitor type matter?
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1answer
50 views

Is there such thing as a 'capacitor socket'?

Or will I have to make one? Something like a 2kV mount for a cap like this (but obviously higher voltage); So you can switch a bunch of different ones in and out, if not, I might have to design ...
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2answers
92 views

Theory of operation for discharging filter capacitors with a MOSFET switch [closed]

Our teaching assistant showed us this circuit, saying that the MOSFET acts as a switch. When the power supply is OFF, the MOSFET allows the filter capacitors to be discharged via the switch circuit. ...
3
votes
2answers
69 views

Voltage source phase shift in RC circuit

I've been doing an analysis on a particular circuit. Nothing too complicated simply a resistor and capicator in series with a 2v supply at 500Hz / 0 degrees. Essentally what im trying to understand ...
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0answers
40 views

Prevent desktop from switching off when power inverter switches from mains to backup

I'm using a desktop computer over a power inverter that's connected to a 12V lead acid battery. When the main power supply fails, the inverter switches to battery backup and can power my desktop for ...
1
vote
1answer
46 views

Calculating the acquisition time of a sample and hold circuit?

I've learning about analog to digital converters. I came to read about the acquisition time of sample and hold circuit. But it confuses me. Can anyone help me to learn how to calculate the acquisition ...
1
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1answer
58 views

Understanding the capacitors in an op amp circuit

I am a computer programmer forced to make some circuits for a Langmuir probe our lab is making (the main task is programming the analytic software on the computer, but I have to make a basic amplifier ...
0
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1answer
70 views

Help Identifying Capacitor

I was given the following capacitor by a spare parts shopkeeper when I asked for a polypropylene capacitor (to be used in RC snubber circuit for a mains load). Can someone confirm this is the right ...
2
votes
2answers
118 views

How does the circuitry work in the Symet robot?

I ordered this Symet robot kit and it only includes instructions on how to build the thing instead of actually teaching you exactly why and how it works. I even ordered this book that walks you ...
0
votes
3answers
59 views

78L05 questions [duplicate]

What are the capacitors on the input and output of a 78L05 for? I saw a lot of different schematics with a lot of different input and output capacitor values. So now I am really confused, and I'm ...
1
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3answers
82 views

Can I charge capacitors in series with voltage higher than the rated voltage of 1 of the capacitors?

I am making a coil gun. I have just ordered some 330uF 200v 105c Radial Electrolytic Capacitor. I will be using the charging circuit from a disposable camera. I know that two of the same caps in ...
1
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1answer
60 views

Building a micro generator, I need to account for the pulsing DC after my 3 phase diode bridge

I wound my own motor, and tested it to be about 300 RPM per volt, and if my noob math is right, it should be able to handle about 1600 watts with a ~40 volt supply without burning my nice but thinly ...
0
votes
2answers
55 views

Is there a way to fix a unsoldered SMD decoupling capacitor?

I'm rather a newbie regarding electronics but I came here to seek for a simple response. I realized that a electronic appliance I have doesn't work anymore. I tried to investigate the issue and found ...
1
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1answer
67 views

Close circuit after a couple of seconds

First post on this site, sorry if it's too basic. I'm learning to interface with a particular chip which has a GPIO pin. I'm using the GPIO for input with a pullup resistor and a switch between the ...
-2
votes
1answer
92 views

using a 100 volt capacitor to charge a 6 volt battery [closed]

Need to charge a 6 volt lead acid battery from a 100 volt 15,000 mfd cap. and control the current flow to the battery.
0
votes
1answer
50 views

Poles in this circuit

Just a simple question, how many poles has this circuit and where are they located?. This circuit is used to represent the process of charging capacitor 2 from a charged capacitor 1. I have this ...
0
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1answer
44 views

Can a LCD display work with swollen capacitors for a large period of time until briefly turned off? [closed]

I am trying to figure out why would my very old SyncMaster 720N stop working after turning it off for a very brief moment. I've already had issues with it, I had to replace some capacitors and then it ...
1
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1answer
43 views

Discharge of a load capacitor through a cascode

How will a cascode effect the discharge of the load capacitor? I would expect that the discharge trough the cascade is slower since the cascode has higher output impedance. simulate this ...
3
votes
3answers
798 views

I want to replace a car dash cam battery with a capacitor

My car dash cam (G1W) has a weak battery. When it dies the camera will not function at all. I have already replaced it once. The original battery was 200ma, but I found a 320ma one that would fit. It ...
1
vote
1answer
101 views

How to solve first-order RC circuit?

I've got a question, and I just keep getting myself confused when I try to solve it. The problem asks to find voltage and current and resistor currents transients (the switch is opened at t=0). ...
1
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2answers
93 views

How to calculate a electrolytic capacitor based on current and voltage to have the smallest ripple

I have built a circuit involving LEDs powered on 230V AC. The LED current driver that is powered on 30V and contains 10 LEDs of 1W each. 10 of these modules are linked in series and are ...
2
votes
3answers
621 views

Can a 6.3v capacitor be replaced with a 16v capacitor? [closed]

I'm repairing my old 478 socket computer motherboard and two 6.3v 2200uF capacitors near the CPU are bust. The computer still powers on, but it doesn't pass the BIOS screen without the ps/2 mouse ...