Questions tagged [electrolytic-capacitor]
An energy-dense capacitor type, used in low frequency filtering applications.
236
questions
8
votes
2answers
7k 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
2answers
36 views
Electrolytic capacitor polarity voltages
What happens if we feed an electrolytic capacitor only positive voltages while keeping the negative pin voltage lower than positive. for example positive pin 20V and negative pin 5V.
Does it affect ...
10
votes
1answer
1k views
Desoldering a through hole capacitor with weird terminals
Apologies in advance if this is the wrong place to post this question.
So I've just RGB modded an old CRT TV, and now I'm trying to replace a series of capacitors to hopefully fix some screen ...
0
votes
1answer
72 views
Can failure of an old electrolytic capacitor be precipitated by motion?
I have report of a circuit board failure. The board was 20+ years old, and included at least one electrolytic capacitor. That capacitor would then be beyond its expected useful life. The board was ...
12
votes
5answers
3k views
High short circuit failure rate of aluminum electrolytic capacitors during the production processes
I have produced 1000 units of our new developed energy meter. Almost 20 aluminum electrolytic capacitors (2%) have failed short when we test them during the production processes. The Capacitor is a ...
0
votes
2answers
100 views
Charging 2 super capacitors in series
I have recently received my order of 2 2.7V 500F super capacitors from eBay.
After much searching, my yet unanswered question is:
Can I connect both of these capacitors in series and charge with 5V ...
1
vote
1answer
67 views
Coilgun capacitor reverse voltage in my schematic?
I'm going to build a coilgun and have thought about all possible problems, which I solved except the reverse voltage problem. I designed a schematic based on some other schematics I found online. My ...
1
vote
1answer
87 views
Can a smd aluminum electrolytic capacitor be replaced with a normal electrolytic cap?
I have a JBL Charge 2+ amplifier that during dissasembly I missed a major step and accidentally broke off about 2 to 4 of the SMD electrolytic caps. Instead of buying replacement ones I already have ...
-1
votes
1answer
173 views
What is the use of a capacitor in a DC motor circuit?
I'm trying to understand all the components I need in order to drive a DC motor through an Arduino.
I saw this circuit below, which has a capacitor (other sources show same circuit but without the ...
8
votes
3answers
1k views
Why should care be taken while closing a capacitive circuit?
The other day in class, our professor told us that care should be taken while closing a capacitive circuit and while opening an inductive circuit.
Why is this so?
I partly understand the inductive ...
0
votes
2answers
112 views
Why use both big polarized cap and small non-polarized cap in the TB6612FNG DC motor controller terminal?
In the datasheet of TB6612FNG DC motor controller, Typical Application Diagram section.
Both DC sources are smoothed by caps. But I don't understand why there are two caps in each position.
The ...
0
votes
1answer
81 views
My RT8272 buck dc converter fried in my test charging circuit for arduino
I'm building a circuit to power an arduino and later a stepper motor from a 3A 24V DC source. The DC power source is a switching power supply, much like those used in notebooks.
I'll need after ...
2
votes
1answer
81 views
Can a castellated PCB/module have electrolytic capacitors in it?
We're designing a small module (3in x 3in) that will have castellations on the edges for connection. I just watched a video on castellation PCB design. The video talked about the module going thru ...
0
votes
0answers
44 views
How to calculate a capacitor's discharge time? [duplicate]
How do i calculate a capacitor with a specific capacitance loaded with a specific resistance discharge time and reach a specific voltage?
So let's say i have a 22uF capacitor charged with 12 volts ...
0
votes
2answers
53 views
Discharging radial electrolytic capacitors
I'm a beginner/intermediate in electric engineering and had to discharge a few electrolytic capacitors last week in a hobby starter kit (not too high voltage) and now I have to discharge some more ...
15
votes
1answer
563 views
Why do some devices use electrolytic capacitors instead of ceramics for small value components?
I've recently run into a number of consumer-grade devices that use 50v, 0.22uF electrolytic capacitors, as well as other similarly rated parts, all below about 10uF. In use, the voltages on them are ...
4
votes
1answer
78 views
Safe way to reform high-voltage capacitor
This week I received an old photographic studio flash unit made in the early 1960'ies. Inside is a huge 40µF/2500V capacitor. I don't know the usage history of the unit; it may not have been used for ...
2
votes
0answers
24 views
Aluminum Electrolytic Capacitor submersed in synthetic (PAO) oil
We are testing solar water pumps which have the 3phase inverter for the BLDC in the down hole pump. The boards (one power board, one controller board) are submersed in the lubricant oil that is used ...
2
votes
1answer
70 views
Assembling and Dis-assembling a Charged Capacitor
If I have an electrolytic capacitor, which is a cylindrical body in which the two plates are rolled-up with a dielectric paper in between them, of very high value (say 1F) and I charge it using a DC ...
0
votes
1answer
62 views
Brand / Supplier of this capacitor
Having trouble to identify this capacitor, not for its values but its specifics. They're all being used in the AKAI reference series. This particular photo was taken from the power supply board of the ...
23
votes
3answers
4k views
Is the capacitor drawn or wired wrongly?
In my recent study of electronics, I chance upon a guide on building a line-following robot. In one of the diagram shown, I realized that the capacitors, namely, C1, C2, C4 and C5, all marked with red ...
0
votes
1answer
71 views
Two modes of electrostatic force with charged capacitors?
During a charged state of a capacitor (Regardless of the type of capacitor),
Simple parallel plate:
.png
Parallel plate with dielectric material in the gap:
]3
Supercapacitor:
How is the ...
1
vote
2answers
527 views
Bulk Capacitor for Motor Driver
I'm creating a motor driver for a BLDC motor. I was wondering how we can calculate or choose what capacitance we need for our purposes.
We're using the motor driver for a chain drive /transmission ...
2
votes
1answer
518 views
Can you identify these SMD Electrolytic capacitors? [closed]
I'm fairly sure I need to replace the capacitors in this LCD panel from 1993, but I'm not 100% sure I'm reading them correctly.
I'm guessing that the large ones are 47uF 16V, the medium ones are 10uF ...
1
vote
2answers
122 views
Decoupling capacitor placements and ratings - how to choose?
I am building a circuit with 2 hybrid stepper motors each powered by a stepper motor driver A4988 and both drivers are connected to an Arduino UNO R3.
Before soldering the components together on a ...
0
votes
1answer
93 views
How to tell if a printed capacitance is the actual value or a capacitance code?
My confusion was inspired by this question. The OP asked to identify an electrolytic surface mount capacitor and its ratings. I answered assuming the pictured capacitor's capacitance was a three ...
0
votes
1answer
183 views
Will this capacitive discharge welder design work?
I'm an electronics newbie trying to learn about the subject through tinkering, and my current project is a capacitive discharge welder for welding on battery terminals. I thought I'd better have ...
2
votes
1answer
54 views
What happens when a Cap fails?
I am trying to understand What happens when the Electrolytic caps fail at the input terminal of a charger? What about at the output of the bridge rectifier?
These two caps below are rated 100uF @ 200V....
1
vote
3answers
813 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 ...
1
vote
2answers
220 views
Why do bipolar electrolytic caps have a long and short lead?
Ok maybe not all, but the Nichicon UES series of bipolar "audio-grade" electrolytic through-hole caps have a short lead and a long lead..
Why?
The datasheet has nothing to say about it.
This fairly ...
1
vote
0answers
68 views
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 ...
11
votes
1answer
978 views
Storage of electrolytic capacitors - how long?
I have a high voltage (750V) high value electrolytic cap about as big as my forearm. It has been in my storage box for about 20 years. In general, do electrolytics degrade under normal storage ...
1
vote
1answer
209 views
Why is the electrolytic capacitor not polarity sensitive?
The issue
I was making a project in which I had to use a 2.2uF electrolytic capacitor in series with a microphone and weirdly, the circuit works even if I toggle the polarity of the capacitor, that ...
15
votes
3answers
488 views
Maximal operational pressure of tantalum and electrolytic capacitors
I need to design a device that have to operate in an high pressure environment (Nitrogen gas). The operational pressure may vary from 1bar (atmospheric) up to 20..30bar gauge pressure. The regular ...
0
votes
2answers
242 views
Replacing a Capacitor on an Onkyo HT-R960 A/V Receiver
I have an Onkyo HT-R960 receiver that's been acting very flaky for the past couple of months. I've had to let it warm up for several minutes before being able to use it. I would also have to turn it ...
1
vote
3answers
574 views
Capacitor max safe operating voltage
I'm currently making a power supply with a 32 volt AC out, so the rectified voltage would be 32*1.414-diode drop. The value comes around 44 volts. My question is, is it okay to hook up a 50 V rated ...
1
vote
1answer
180 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
1answer
96 views
What is this solar power RC circuit doing?
I am a CSE student working on a project.
We are using a solar powered microcontroller. The solar panel's power goes through a fuse and an RC circuit with a varistor to the charging system.
What ...
0
votes
1answer
58 views
Series capacitors; negative voltage
Interesting observation today; I set up a series stack of 4 cheap electrolytic capacitors (10V 220u) and after about 5 mins of applying 30V the lower most cap had settled at -300mV. The other three ...
1
vote
2answers
403 views
Identifying polarity of capacitor from PCB printing
I took out the old capacitor and didn't remember to check the polarity because I assumed the board would have more standard markings. Is there any way to figure it out with a meter or by the printing?
2
votes
2answers
360 views
Non-Polarized Electrolytic Capacitor Replacement
To the best of my abilities, I'm trying to repair an Atari 800XL which was sold as "non working unit". I found a new graphics chip and it's working ok. I though that, since I had it opened up, it ...
2
votes
1answer
99 views
How far does reforming a capacitor help? Does it have any adverse effect on using such a capacitor on components?
I read a few articles on the internet about reforming capacitors. Does this actually apply only to a capacitor that was stored during a certain period of time or can it be used on any electrolytic ...
2
votes
1answer
178 views
electrolytic cap shelf-life after being mounted on circuit borad
My question is about whether there would be a problem with aluminum electrolytic capacitors that have been installed in an amplifier, then factory tested (so a current was run through them), then ...
2
votes
0answers
161 views
Replace filtering(?) capacitor on CRT deflection Board
I am doing partial recap on CRT monitor Sony PVM 20m2e. (monitor was working, but RGB lines at the top of screen which should be hidden were visible and geometry is not top notch)
I desoldered C584 ...
6
votes
2answers
3k views
How to avoid a electrolytic capacitor on a (audio) signal path?
I've built a compressor basing on the all-in-one chip THAT4301. It works well. But I'm still not happy because of the electrolytic capacitor I used in the signal path. My design was based on the ...
1
vote
1answer
3k views
Can I change a capacitor with one with a higher capacitance?
Hi I have just joined after lurking a lot because I haven't found an answer that was specific enough for me.
I have a Soviet synthesizer (TOM 1501) and it has some odd defects such as clicking noises ...
1
vote
3answers
208 views
How an electrolytic capacitor survives in negative half cycle?
An electrolytic capacitor doesn't like higher voltage at its opposite terminal i.e higher voltage should only be at positive terminal as per convention.If that so how the capacitor survives in this ...
4
votes
2answers
435 views
Can I place an electrolytic capacitor close to a solder point on a two sided pcb?
I’m designing a pcb, which is going to be installed inside a metal chassis. To minimize space I will make it a two sided pcb. (See pictures)
Because there will be parts mounted on the top face of the ...
18
votes
3answers
2k 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 ...
0
votes
1answer
75 views
Chargng Capacitors in series
I am trying to build a capacitor bank for a project in order to feed an inductor with "high" voltage(500V) however I only have a dc generator rated at 100V at my disposal. Charging 5 identical ...
