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

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22 views

Start capacitor on shaded pole to increase starting torque- how to size

Can I add a capacitor to a shaded pole motor to increase starting capacity? How do I size it? I have a single pole squirrel cage motor running a conveyor toaster that is dying while trying to start. ...
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1answer
43 views

Total charge on capacitors in series

When we calculate the equivalent of the capacitors that are in series and are connected to a battery we assume that the total charge on each capacitor is equal to the next one. When I look at two ...
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0answers
43 views

does polarity matters in this AC circuit

I am using the following circuit to drive a single phase AC motor using a microcontroller. I am worried about the polarity and need to know if it would be a problem if the polarity is switched, ...
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4answers
557 views

Why does capacitance value changes with applied voltage?

I searched many forums and papers on google and haven't came up with anything. Even asked my teachs and they did not know. One said something about piezo effect but she was not sure about it. So here ...
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2answers
73 views

misconception of full wave and half wave filter rectifiers [duplicate]

Can someone please explain to me "The difference" in output voltage between the full wave and half wave rectifiers. Im asking about circuits with a single diode and 2 diodes .. NOT bridge circuit. And ...
2
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2answers
152 views

Replace foil caps with ceramic caps?

I am repairing a battery pack (see below) which has some old foil capacitor (100nF) between a sense Terminal and the negative (together with a NTC thermistor). Can I replace the foil cap with a X7R ...
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5answers
1k views

Why are charge pumps only used for low current applications?

Typically the most expensive (and hard to get) elements in a SMPS are the inductors. Thus I was wondering if it's possible to use inductor-less switching mode power supplies (i.e. charge pumps) for ...
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0answers
47 views

How do capacitors work

Ive been reading up on capacitors. But most stuff is over my head. I'm considering a system with the following attributes: Capacitor: 12 VDC, 0.5 Farad. Power supply: 5 VDC, 1 amp What will the ...
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1answer
29 views

How to wire an AC induction motor

How do I get the ceiling fan motor below wired, and how do I enable speed control? Our AC outlet supplies 220V, and the motor comes with a 1.5uF capacitor. I understand I would need an h-bridge ...
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1answer
59 views

Series capacitor balancing in RC filter

I am trying to make a 600v RC filter with a cutoff frequency of 1hz or less. The problem is the capacitor prices for these voltages are too high. I want to use series capacitors to up the voltage ...
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2answers
64 views

Capapcitor value in schematic with “mk” units

I've got a schematic that originated in Brazil that generally uses European symbols rather then US. But some values for capacitors are confusing me. There are several that are marked 100n and so ...
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0answers
37 views

Help fixing board with burned capacitor [closed]

I have a board from a sound bar with a burned component. I think it was a capacitor but I'm not sure the best method to verify and figure out the right part to replace it with. If it's not ...
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0answers
21 views

Connecting Capacitance-to-Digital IC to XBee

Do I need a microcontroller to connect a capacitance-to-digital chip to an XBee module? I want to build a soil moisture monitor that transmits data via XBee modules. I have decided to measure soil ...
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2answers
57 views

Replace Tight Capacitors for Better Tolerance?

There are some capacitors (10 \micro F and 4.7 \micro F) which are limiting my development of Raspberry Pi Hats because they are provided only with tolerance of 10% or greater. It seems that the ...
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2answers
39 views

Capacitor for current transformer measurement circuit

I want to measure an AC current with a current transformer and an arduino device. I found on a website ...
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2answers
68 views

What does a large capacitor do in small signal analysis?

I keep having to look this up. It seems as though I have yet to find a great way to understand this. In small signal analysis: What is the difference between a large and small capacitor? What are ...
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1answer
64 views

Charging and discharging of capacitors

I simulated this circuit in TINA-TI. However I could not understand the output waveform for the negative half of the cycle. Waveform: Green- Voltage across C2 (10 u cap) Brown- Voltage across C1 (1 ...
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2answers
55 views

Power of a capacitor when is connected to a battery

According to definition of power ( current times voltage) since there is no change in charge, the power stored in a capacitor connected to a DC voltage is zero. Since energy is power times time, ...
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2answers
68 views

Physics explanation of charging time by increasing dielectric constant

I am having a problem understanding in physics of the relationship between charging time and dielectric constant of a parallel plate capacitor. I'd like about physics aspect not based on time ...
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0answers
37 views

Solor Panel and Super Capcitor

I need some help trying to figure out the sizing needed for a solar panel and super capacitor. The overall design is a solar panel hooked up to an energy harvesting chip that charges a supercap. The ...
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votes
2answers
129 views

100nF MLCC bypass capacitor spontaneously exploding on 3.3V bus, how does this even happen?

A 1608/0603 multilayer ceramic chip capacitor was functioning as a bypass capacitor for the 3.3V supply of a InvenSense MPU-6050 6 axis (gyro + accelerometer) MEMS sensor. It somehow exploded forming ...
3
votes
2answers
64 views

DIY DC Blocking Capacitor for oscilloscope

I'm studying switching converters and want a bench setup that will allow me to reliably observe the various voltage waveforms (output, inductor, switch) on my oscilloscope. I discovered pretty ...
3
votes
1answer
38 views

add run capacitor to capacitor start motor to increase efficiency

Can I add a run capacitor to a capacitor start motor to increase its efficiency? I remember doing this 20 years ago and the run current dropped 20% or so, but I didn't measure the power consumed. The ...
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4answers
135 views

Capacitors in parallel without resistance

For the following circuit, at time 0, the switch switches from A to B, figure out the voltage wave form at B. The question I am concerned with is whether the voltage across the capacitors will ...
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1answer
53 views

active bleeder circuit for capacitor discharge

I have a circuit with a large capacitor, a solenoid and an N-channel FET fed by a 60VDC supply. When I trigger the FET the capacitor discharge activates the solenoid. This all works as expected ...
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1answer
47 views

How do I work out energy stored in a capacitor bank?

I would like to know how to work out energy stored in a capacitor bank ? I have done my own working outs and have reached an answer of 0.192J, I don't know if this is correct ?
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0answers
47 views

Simple DC ramp up circuit

I am after a simple circuit that ramps from 0 to VCC relatively linear over a few seconds and ramps down only when power is removed for around the same time. I have been advised an RC circuit may be ...
3
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2answers
53 views

capacitor ripple current in buck converter

I designing a step-down buck converter and i'm a little bit worried about ripple current which flows through the output capacitors. In my research on internet i found that ripple current essentialy ...
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0answers
44 views

Overcoming rotor magnetic field when magnetizing stator in a Halbach motor

I am currently building a high static torque motor using electropermanent magnets arranged in a circular Halbach array as so: I've coiled magnet wire around the 12 alnico magnets making up the ...
0
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1answer
62 views

DC/DC Converter Instant Off

The output voltage of my DC/DC converter and my power supply both slowly descend. I believe this is due to capacitors being close to the output of each device. I want to get an instantaneous, or as ...
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2answers
81 views

Finding the voltage on a capacitor

Each capacitor is \$24\text{nF}\$ and I need to find the voltage on \$C_\text2\$. \$C_1+C_4=2*24=48nF\$ \$\frac{1}{C_\text{(1+4)||2}}=\frac{1}{C_\text{1+4}}+\frac{1}{C_2}=\frac{1}{16}\$ ...
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0answers
43 views

Using crystal in LTspice (where to get values for RCL)?

I'd like to simulate a schematic in LTspice driven by a crystal. An capacitor representing the crytal (as a resonant circuit) however it needs some specific values. Is there a table of common values ...
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0answers
45 views

Using capacitors to transmit low frequency information to one's finger

I would appreciate any specific help on this question. Part numbers would be a great help. Instead of cancelling vibrations from capacitors, I want to utilize them to convey information to a person ...
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1answer
59 views

whats the maximum voltage that can be given to a capacitor

i have a 10uF capacitor so what is the maximum voltage that can be connected across it? please explain in high school level terms
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1answer
70 views

Is it safe to use an Y2 Capacitor where an X capacitor used to be?

Is it safe to use an Y2 Capacitor where an X capacitor used to be? I mean Y should be safer right? So Y2 where X should be is OK, but not the other way around, right?
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1answer
58 views

Can I use any capacitor for a 2 phase AC motor?

So recently I got my hands on an old pump motor, unfortunately the connection diagram is missing. I have already determined this is a 2 phase motor, and that in order to make it work I need a ...
0
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0answers
56 views

How to drive a capacitor from an AC current source

I am wondering how it is possible to drive a constant ac current through a capacitor. I would like to use a transistor as the current source/sink. The problem is that if I put the capacitor in the ...
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2answers
26 views

LT3750 Capacitor Charger DONE pin

I'm drawing out a circuit using Linear's LT3750. I don't quite understand the DONE pin. What I want to do is add an LED and have it come on when charging is done. Like in a camera. Can someone suggest ...
3
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1answer
37 views

Capacitors in parallel

I am using a old disposable camera to charge and discharge my Cap. I got 4 Caps and Connected them in Parallel (Hots to hots as is Grounds to Grounds). Can I use this just like normal? Can I just hook ...
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2answers
52 views

AC Watchdog Circuit

I've designed a small AC-based watchdog circuit for my Raspberry Pi (schematic below). A buddy of mine looked at it and said that it was complicated, and there might be problems with asymmetric ...
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2answers
77 views

Newbie question - sawtooth signal generation - capacitor discharge via bjt

I'm trying to realize a sawtooth wave generator. The circuit is composed by an op-amp integrator which creates the ramp. Then the integrator output is chained to a comparator with a fixed threshold, ...
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0answers
34 views

Very low-power digital multiplexed open-drain sensing quandary

This is sort-of related to another question I asked awhile ago. simulate this circuit – Schematic created using CircuitLab This is for an alarm motion-sensing application, so is normally ...
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1answer
36 views

(super) capacitor to stabilize lightweight arduino led flashlight/beeper

i have set up an arduino (3.3 v) as a 48 hour beeper and led flasher for a high altitude ballon project. i successfully powered it with a button battery (3 v). now i exchanged the 20-mA-led with ...
0
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1answer
30 views

Energy Harvesting, Equivalent Capacitance of Battery Formula

So I was reading through TI's datasheet for their BQ25505 here, and came across the following: 8.1.2 Storage Element Selection In order for the charge management circuitry to protect the ...
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3answers
45 views

Current split between resistor and capacitor in parallel

I'm interested in knowing the formula which represents the voltage across the 10 ohm resistor. I know that it's going to be the current multiplied by the resistance, which means I have to find the ...
0
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1answer
56 views

Use of a bulk capacitor with a 5V MCU controlled motor circuit

I have a circuit as such that will ultimately be used for a remote controlled race car: I have a 5V power regulator (SMPS) to take 4 AA batteries to 5V. With this, I will power a Raspberry Pi, a DC ...
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3answers
126 views

Capacitors -> Storing 500 Joules in a capacitor with a simple 9 volt battery

I am a newbie to not only this forum, but electrical hobby(ing) also. I need 500 Joules within a few milliseconds from a capacitance. I plan to make this capacitance at "home". I plan on using a ...
0
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3answers
121 views

What does a capacitor capacity really mean?

I am very new to electronics, and I am trying to use a capacitor to make my LED's stay on a little longer after I turn it off. I know that the voltage on the capacitor is the maximum limit of voltage ...
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2answers
49 views

Current step to LC circuit

An inductor is a device which adjusts its voltage to keep the same current flowing through. However, the current exponentially decays when there is no source any more. Similarly, a capacitor is a ...
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3answers
97 views

Booster Converter Question

So i've been learning about boost converters, and it makes sense. From what I understand in the schematic below when the switch closes the inductor receives a large amount of current (since we have no ...