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Questions tagged [electrolytic-capacitor]

An energy-dense polarized capacitor type, used in low-frequency filtering applications.

0 votes
1 answer
34 views

Energy stored in a capacitor with dielectric

This is a problem from a book. The exact words of the problem are below: A condenser of 1 µF contains titanium oxide (\$TiO_2\$) as a dielecric with \$ε_r\$ = 100. For an applied D-C voltage of 1000 ...
0 votes
1 answer
94 views

Why are there capacitors in series in this AC/DC converter?

In a circuit with an AC/DC converter that supplies 12V and then only 11.4V because of a diode (D16), I have found capacitors in series (C33 and C38, each 100µF 35V.) That makes no sense to me since ...
9 votes
3 answers
2k views

Can an electrolytic capacitor withstand 0.1 V reverse polarity?

Let’s start the question with a brief description of my application. I am trying to attach a headphone jack with a detect pin to a RDA5807 IC based FM radio project. I am using a separate ...
0 votes
1 answer
31 views

Multiple smaller capacitors on power rail for NeoPixel / WS2812B strip

I read in the AdaFruit guide that a 500-1000uF capacitor is recommended on the power rail. However, electrolytic capacitors in this capacitance are quite large. Depending on the length of the strip, ...
0 votes
1 answer
68 views

Cyclic Voltammetry for a Capacitor - Positive Current, Potential is decreasing?

In the boxed red region, why is the potential decreasing when the current is still positive? To my understanding, when the current is still positive (i.e. not changing direction), the capacitor will ...
1 vote
1 answer
129 views

Why conductor having charge(let say 1C) have tremendous potential but same conductor used in capacitor have low voltage?

When we talk about electrolytic capacitors or the supercapacitors (EDLC), then we know that we can store large amount of charges in it. Since in electrolytic capacitors the aluminum plate acts as ...
1 vote
1 answer
194 views

How does temperature affect ripple current parameter in electrolytic capacitors?

A maximum ripple current declared, for example, at 100 kHz and at a temperature of +105 ℃ for an electrolytic capacitor, if estimated at a temperature of +85 °C, how much does it increase? What order ...
1 vote
2 answers
93 views

Decoupling capacitors for operational amplifiers

when in the refence design of an amplifier (for example OPA856) we see the + sign in a capacitor schematic, does this necessarily means we should use electrolytic capacitors? If there is no positive ...
-3 votes
3 answers
126 views

Blowing up capacitors with a 9v battery [closed]

Hello, I have a 9V battery I would like to blow up some capacitors with; currently I have 6.3v 180uF capacitors that don't seem to blow up at least in a good time(I'm aiming for <5 seconds), they ...
18 votes
3 answers
4k views

How to Measure Very Large Capacitance e.g. Super/Ultra Capacitors

I have recently acquired a couple of mysterious ultra/super capacitors from my brother. Apparently he doesn't remember any of the specifications or even brand... To further complicate matters, they ...
1 vote
1 answer
651 views

Two polarized electrolytic capacitors in series VS two bipolars in parallel

I need one bipolar 4.7uF 50v electrolytic capacitor. I have polarized 10uf 50v capacitors and bipolar 2.2uF 50v capacitors. I can place two of the 10uF in series (negative leads joined) or two of ...
1 vote
1 answer
369 views

THAT4315 audio analyzer - capacitors getting hot

I have designed a audio spectrum analyzer circuit with THAT4315 and a drivers for IN-13 bar graph nixie tube to visualize the signal level. To supply +-12V to the opamps, the Meanwell NSD15 module is ...
0 votes
0 answers
22 views

Lithium Ion Battery : Electrolytic Capacitor At Buck Converter Output

It is recommended not to parallel electrolytic capacitors with a battery due to the leakage current of the electrolytic capacitor (which is small but worthy of consideration over large time periods) ...
1 vote
1 answer
89 views

Electrolytic 3-lead capacitor

I have a 3-lead capacitor that I'm having a hard time identifying. It is from an old Lafayette PF-30 receiver. I don't have schematics or a manual. It has a high squeal when turned on, and my first ...
1 vote
1 answer
56 views

Possibillity of reverse polarity of Aluminum Electrolytic Capacitor

Introduction First of all, this question more like theorical rather than practical as I want to test my understanding about Aluminum Electrolytic Capacitor, which I will later called Al-Cap for short. ...
0 votes
1 answer
57 views

Power schematic questions

I received a guitar pedal in poor condition and looking to repair. Checking through the schematic, it appeared the electrolytic caps were installed backwards. All other picture I could find online ...
2 votes
1 answer
332 views

How to identify surface mount electrolytic capacitors?

Various surface mount electrolytic capacitors seem to have no consistent marking method. Here are some examples: (Image sources: 1, 2, 3) How can I identify what value and voltage rating these are?
2 votes
1 answer
4k views

Surface mounted electrolytic capacitor markings

Is this 22 µF / 16V? General rule of thumb for these markings?
0 votes
1 answer
147 views

Precise capacitor in parallel to power supply

I found this schematic in ADNS-2610 datasheet. There are two capacitors in parallel between pins 6 and 7 (GND and VDD.) One is 4.7 uF and the another is 0.1 uF, so the parallel result is 4.8 uF. Why ...
0 votes
1 answer
233 views

Probability of explosion of a 100 µF, 25V capacitor when powered at 5V [closed]

I have a system which uses this board: Arceli Motor Control Speed. It's supposed to run for a maximum of 5 hours continuously. It has an electrolytic capacitor (black vertical tube) on which is ...
10 votes
2 answers
9k views

Why do some SMD electrolytic capacitors have platforms?

I’m working on a computer monitor’s power board (to replace a capacitor or two, which I assume is the problem), and found these: Replacements are easy to find, so no issues there, but I’m curious why ...
0 votes
1 answer
144 views

Can you replace ceramic or tantalum capacitors with aluminum electrolytic capacitors?

I have a question about the hookup for my 12VDC to 5VDC step down module - the K7805JT-500R3. It states in the datasheet that ceramic capacitors are what can be used but it also states that tantalum ...
1 vote
1 answer
213 views

EMI filter attenuation requirement for a buck converter given EMI compliant AC-DC converter

In my application I have an off the shelf 600W 72V AC-DC converter that generates the main DC bus that powers a custom board that houses a 72V input, 9A output buck converter switching at 330kHz. A ...
5 votes
1 answer
1k views

Electrolytics and PCB Routing

In researching whether or not it's common practice to run traces/place vias underneath electrolytic capacitors (specifically SMD electrolytics, didn't seem like it would be an issue to me), I came ...
0 votes
1 answer
87 views

Calculate capacitor charging constant time connected to battery and boost converter

I know the formula to calculate the constant time for capacitor is t=RC and for full charge t=5RC. In the following example there is not resistor in the circuit but of course we are not in the ideal ...
0 votes
1 answer
91 views

Mystery Voltage Across Reverse Biased Diode

I'm observing a mysterious behavior that I cannot explain. NOTE: Where I use the word "instantly" below I mean this occurs in less than the 1 ms scale I'm using on my digital scope. Also, I'...
3 votes
4 answers
7k views

Can you replace electrolytic capacitors with tantalum ones?

Due to size constraints on a custom PCB, I have opted out for using the smallest type of electrolytic capacitors (3 mm diameter.) However, capacitors in such a small diameter are almost impossible to ...
0 votes
2 answers
125 views

What is the capacitor needed for 30 kHz power rectifier?

I need to rectify 200 V at 30 kHz for a resistive load of 3-4 kW. I use a 1200 V/60 A Schottky diode bridge. I have some 6800 uF/450 V capacitors. Can I use them, or should I use other values? Is ...
1 vote
0 answers
98 views

How can I measure the voltage of a capacitor using multimeter?

I'm new to electronic and trying to measure a capacitor (Aluminum Electrolytic one) using a multimeter. The cap is already charged. What I did is to touch the positive leg of the cap with the red ...
3 votes
2 answers
2k views

Green vs black capacitor (aluminum)

I seem to have defective capacitors on a board and I am looking at buying new one to change them. The actual capacitors are green. I noticed that the green ones are more expensive than the black ones ...

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