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

learn more… | top users | synonyms

0
votes
1answer
79 views

5v power supply using 7805

I want to create a 5v power supply design to provide power to my PIC18F4550, for that I am using 7805 so it will give the required 5v as output. I searched online and this is the diagram I found:- ...
0
votes
0answers
15 views

Circuit modification of OSBee shield for Arduino

I purchased OSBee shield board to control 24V Solenoid Valve. It utilized 5V external power to charge a capacitor and then release charge to open/close solenoid valve. However, I found sometimes it ...
0
votes
1answer
58 views

Simple High Side IGBT Switch

I'm trying to design a capacitor discharge circuit for a hobby rocket launching system. In some cases we have long wire runs with multiple rockets so a CD circuit seemed the way to go. I'm trying to ...
0
votes
1answer
70 views

Charging capacitor with higher voltage power supply

I have a maxwell 1200F 2.7V ultracapacitor which I charge using a 16V supply and a voltage divider in parallel with the capacitor. It's a really slow charge. I also have a 4V supply which has higher ...
-1
votes
0answers
21 views

AD7745/6 capacitance measurement

I am going to use AD7746 to measure capacitor in ranged 0 - 4pF. Can the resolution be 0.04fF? Finally, I would like to input the result to arduino uno.
1
vote
0answers
39 views

How do I find the right replacement capacitors? [closed]

I am new to the world of small scale electronics, and am attempting to repair a small flat screen TV, more as a learning experience really, and if it works, awesome! After doing a little googling, I ...
1
vote
0answers
121 views

Supercapacitor discharging

I had bought a Maxwell ultracapacitor (this one) rated for 1200F at 2.7V. Its ESR according to the datasheet should in ballpark of 0.4 milliohms. It got delivered today and is undamaged and new by ...
0
votes
0answers
18 views

Triggering Problem in 100W LED driver

Why a triggering problem, 100 Watt Driver(volts @ 3ampers), instantly it switches On, but once it is off again it wont switch on.Why does this happens in a led driver. Is this due to capacitors ...
0
votes
2answers
62 views

Timing circuit with op amps and capacitors

I understand how a basic comparator op amp works and how a capacitor charges individually, but I can't seem to put it all together to make this circuit. I think I might be messing up with the voltage ...
0
votes
2answers
28 views

reading capacitance on digital meter

So I bought this digital meter from radioshack because it tests capacitance. I have several caps on a TV power board, most of which are 47uf and 470uf with various voltages. when I check with the ...
0
votes
2answers
59 views

capacitor discharge direction

This is probably a dumb question, but I am sort of confused. What direction does a cap discharge when a system is turned off? For example, decoupling caps that go to ground. When I shut a system down, ...
6
votes
5answers
631 views

Why pulsed DC passes through a capacitor?

OK, the current flowing through a capacitor equals C*dV/dt, I'm aware of that. What I don't understand is the physics of the process: why does a capacitor pass pulsed DC (0-10V for example) when ...
1
vote
1answer
85 views

quick charge but slow discharge of a capacitor

I'm trying to find a circuit that will quickly charge a capacitor with a load(led) in the circuit but slowly discharge it (keep the led on longer than it took to turn on). Is this possible? Does ...
1
vote
1answer
72 views

When is a 6.3V capacitor not a 6.3V capacitor?

I'm building another (!) rather large WS2812B-based LED installation project and I'm now at a point where I'm suffering from what looks to be a power problem. The standard advice is to put a large ...
-6
votes
0answers
60 views

Trying to get a gain of -2

What capacitor will this circuit have a gain of -2 at 40 kHz? The op- amp has an open loop gain of at least 10000 at this frequency.
0
votes
0answers
49 views

How can I test for charge leakage from a capacitor?

If I wish to check a discharging capacitor for charge leakage, how could I go about doing so with only the simple setup of a cell, capacitor, voltmeter and fixed resistor, plus leads where needed?
-5
votes
2answers
53 views

how to calculate the capacitance for variable power supply 0-20v

I am trying to make a variable power supply of 0-20 V; as we all know it uses a step down transformer, bridge circuit, then capacitors and LM317 regulator But I want to know how the value of ...
0
votes
2answers
69 views

Multi-stage amplifier coupling

For my final project in my electronics course this semester, I need to design an amplifier with a specific set of parameters. Specifically, it needs to have a gain of 100, a voltage swing of at least ...
0
votes
1answer
54 views

Can two capacitors be used in series to get a equivalent capacitance in a circuit?

I am building a FM radio circuit and a 27pF capacitor(Ceramic) is required in that, but i don't have one. But i do have 56pF capacitors. So i was thinking that can i use two 56pF in series to get a ...
1
vote
1answer
52 views

Capacitor with multiple pins

I have a capacitor with 3 pins + 4 for assembly(common ground?). It is paired and I found it in an old (tube/valve amplifier) TV. I couldn't find any docs about it. It has written on it: Tesla TC ...
0
votes
1answer
55 views

Suitable replacement for this big aluminium can capacitor?

In the picture you can see the type of capacitor im dealing with. The specific one is actually the third in the picture, but I took the picture of the easier to see one. The one that has failed is a ...
0
votes
2answers
66 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 ...
2
votes
1answer
47 views

capacitive action in transmission lines [closed]

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 ...
0
votes
1answer
22 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
votes
2answers
366 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 ...
0
votes
0answers
17 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 ...
0
votes
1answer
24 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 ...
0
votes
0answers
23 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?
-1
votes
2answers
68 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
99 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 ...
1
vote
1answer
41 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 ...
1
vote
1answer
41 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. ...
0
votes
4answers
99 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 ...
0
votes
1answer
73 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
120 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 ...
0
votes
0answers
71 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 ...
1
vote
2answers
142 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? ...
1
vote
3answers
248 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
51 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
votes
2answers
67 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
vote
1answer
63 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 ...
0
votes
0answers
69 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 ...
0
votes
1answer
79 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
votes
1answer
72 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?
0
votes
0answers
22 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
votes
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?
0
votes
1answer
52 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 ...
-1
votes
2answers
100 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
82 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 ...
1
vote
0answers
49 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 ...