Questions tagged [capacitor]

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

3,550 questions
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Modify Ring Contact Sensor in a series of wired security reed switches

After reading the instructables post on the simplisafe sensor I modified the ring sensor and tried to integrate it with my wired sensors. This is what I found: testing with a spooled wire about 20 ...
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Series connection of capacitors

I have some questions for the series connection of capacitors. It would be great if someone could help me get these. What will happen for the below cases when you have 2 capacitors in series and 2 ...
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Compact circuit with multiple PAM8403

I'm building a 6 channel circuit with the PAM8403 (Filterless 3W Class-D Stereo audio amplifier) and was wondering if I could make things more compact by using less components. Is it possible to ...
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Does (stray) capacitance depend on voltage?

While thinking about how to reduce stray capacitance on my pcb, I got triggered by the question: Should the stray capacitance depend on the voltage difference? Acccording to the equation of ...
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Point of contact with a capacitor plate & rolled design?

With a simple parallel plate design for a capacitor, does point of contact(to the external circuit) matter? I imagine any point(a - e) would yield the same feature in storing/discharging charge. ...
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Linear voltage regulator output capacitance limit

I am in doubt about selecting the value of bulk capacitors for my system. I am going to use LP5907 voltage regulator. According to the datasheet, the maximum output capacitance is 10uF. Does it mean ...
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How to convert 8-bit information containing MIDI note, to square wave signal using basic chips and components? [closed]

Using basic electronic components (capacitors, transistors, etc) and/or chips (555, 74 series, etc) how do I convert from: Input: 8-bits containing the binary representation of a MIDI number "...
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Capacitor discharge

So I came across this article on CircuitDigest where they explained the functionality of a voltage doubler designed with capacitors. The circuit shown is the following: At first capacitor C3 is ...
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Removed all ceramic SMD capacitors without markings on them from the board… what to do? [closed]

When I told a buddy that I am taking electronics courses and learning to manufacture simple homemade PCB boards, he found me a client with an interesting offer: To reverse engineer a small PIC ...
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How do select capacitor for 400A surge currents?

I have a 220nF capacitor in a series with my surge protection circuit. As can be seen from my spice simulation, the capacitor gets a surge of current passing through it under fault conditions, and ...
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A conductive ball connected to a capacitor

I am not asking for a task solution, but rather how to solve a problem. Say I have a ball of radius R, charged to a voltage of U (relative to the ground). I also have a flat capacitor with a side ...
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1V Overshoot and Undershoot on Power Rails of LTE Module

I have designed a PCB (four layer) having SIM7600I LTE Module. The Stackup is: Signal & Component Layer with Ground Pour Internal Ground Power Plane Internal ...
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Must film capacitors be derated according to the voltage applied? [duplicate]

I know electrolytic capacitors must be derated according to the applied voltage, with some losing a significant part of their nominal value at high voltages. Is it a similar case with film capacitors?...
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Circuit that averages voltage

Suppose we have an oscillating signal V(t) with V(t) >= 0. I'm looking for a circuit that averages this signal over a given time so that I can read out the average value directly using a simple ...
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LTSpice PWM Signal Showing Capacitor isn't Fully Discharged

I'd like to create a pwm signal input to mimic a real life situation of a pwm input that shows the capacitors aren't fully discharged. Please see the image below. I am currently able to create the pwm ...
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How do I calculate the voltage across a capacitor when the source is a square wave?

I have a series RC circuit with R= 2.2K Ohm and C=100 nF, and the voltage supply is a 2.5V peak square wave. And I'm not sure how to calculate the voltage across the capacitor.
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Capacitor electron flow

Well I was just wondering, a capacitor is made of 2 metallic plates separated by insulating material. During the charging of the capacitor electrons flow towards the opposite direction the battery's ...
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Are my calculations wrong for the capacitance?

In an earlier post i discussed about the effects of voltage derating on a capacitor. From here i measured the output with DC and AC applied to a highpass filter and found the cutoff frequency with the ...
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Orientation of “bipolar” capacitors on PCB

I've come across a video on a popular and well-respected electronics channel on Youtube where they say that even bipolar capacitors have a preferred orientation in a circuit that minimizes hum and ...
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Multiplexer between Capacitor and Inductor (Tank circuit)

I am trying to design an inductance and capacitance meter with multiple scales, to achieve this I thought a multiplexer can do the job, but it didn't. My question is: What is wrong in this design ...
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Aluminum electrolytic or ceramic capacitors for linear regulator input and output?

I am using this linear voltage regulator. The datasheet indicates the input and output values for the capacitance to use, 1uF and 10uF respectively. Should these capacitors be or a particular type, ...
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Calculate U(t) when capacitor C1 charges C2 via a resistor R

simulate this circuit – Schematic created using CircuitLab The switch SW1 is activated at t=10s and charge from C1 is transferred to C2. The power supply charges continuously with 1kV 1mA. How ...
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How to calculate the reactance of a capacitor with an input signal that is 2 sin waves of difference frequencies added together?

I am trying to calculate the reactance of a capacitor with an input signal that is not a single frequency. For example, x = sin(4t)+sin(5t), or a capacitor that is used in an audio circuit like the ...
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Calculate Capacitor mf for PAM8402 Amp Powered From RPi

Trying to figure out what capacitor mf I should use for a 5v PAM8402 audio amp that is powered by a Raspberry Pi. When the amp is first turned on it triggers the Pi's low voltage warning. I'm using a ...
865 views

How to read the value of this capacitor?

I came across this capacitor in a voltage converter which was converting 9V to 5V. This capacitor was connected at the output of M7805CT (i.e. between the 5V and common terminal) in parallel to ...
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Charging capacitor to power LED with a low current source

I have a 10000uF 6.3V capacitor, and my source is generating 3.3V and 15uA of current. How long will it take to charge it enough so i can pulse a standard 5mm LED for lets say 1 second?.
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Zener diode parallel to RC circuit

In the left hand side part there is a diode in series to parallel RC network. And in the right hand side there is a zener diode in parallel with series RC network. How do these sub circuits operate? ...
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Calculate the turn-off delay of an LED in parallel with a capacitor

I am trying to create a Custom turn off delay for an LED. For this I take an Capacitor in parallel to an LED My Idea so far was: I have the General Equation for an Capacitor. And the General ...
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Clamper circuit, how to apply kirchhoff when the diode is turned around?

in this clamper circuit it's easy for me to determine the output waveform: This is how I do it: In the positive half cycle, the diode is forward biased with a drop of 0.7 V, so the positive half ...
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Why does a capacitor charge faster when there is a diode connected?

In an series RC circuit why does a capacitor charge faster when there is a diode connected in parallel with the resistor? I tested on an oscilloscope, using a square signal and this is what I got. ...
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What capacitors are proper to use for input of AC DC converter?

I am trying to build an 120 AC to 15 DC @ 200 mA converter using a Power Integrations LNK3206P. Using the full bridge rectifier setup on Table 10 from application note AN-70, Cin1 and Cin2 should each ...
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Cause of blowing resistors

Around 10 years ago we bought 3 dimmers for lighting at a venue. In the last year all three showed the same problem: one or multiple resistors of the dimming circuit (6 channels per dimmer, therefore ...
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KVL in the capacitor during transient analysis

I can see that this topic has been discussed many times in this site. But I still can't figure out why I am still not getting my correct equation applying the KVL. Consider a circuit as shown: ...
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Capacitor in the circuit - Bypass capacitor

I was trying to measure the supply current of a CAN transceiver during fault conditions, one thing which I noticed was that during CANH to GND(when the current consumption is supposed to be the ...
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How are capacitor voltage ratings chosen

I'm reading a user document of a dev board. On page 12, there is an explanation of the power management subsystem. The board VBUS and VBAT lines have a decoupling cap rated at 6.3V, whereas the output ...