#capacitors — Public Fediverse posts

The moon could turn astronauts into 'walking, high voltage capacitors' that accidentally zap spacecraft
https://atlas.whatip.xyz/post.php?slug=the-moon-could-turn-astronauts-into-walking-high-voltage-capacitors-that-accidentally-zap-spacecraft
<p>NASA is asking for ideas to stop static electricity from zapping astronauts or critical hardware during
#astronauts #capacitors #walking #voltage

Doing some research for the next video: I figured out that tan delta is the dissipation factor. But what is the quality factor of a capacitor? Is that listed anywhere in the datasheets…?
#capacitors #ee

Ancient caps, which also need to be replaced. Once I remember how to read the values. Then will have to figure out how these vibrator DC supplies work. Ancient technology that came before inverters... #capacitors #electronics #hamradio

Power Supplies: Turning Wall Power into Usable Power

By Cliff Potts, CSO, and Editor-in-Chief of WPS News

Baybay City, Leyte, Philippines — August 28, 2026 — 12:30 p.m.

Throughout this series we have examined individual electronic components.

Resistors limit current.

Capacitors store energy.

Batteries provide portable electrical power.

Relays control larger circuits.

Transformers change voltage.

Now it is time to put many of those pieces together.

The result is called a power supply.

Almost every electronic device ever built has one.

Without a power supply, even the most sophisticated computer, radio, television, or communications system becomes an expensive collection of parts.

The job of a power supply sounds simple.

Take electricity from one source.

Convert it into the form the equipment actually needs.

In reality, that simple description hides some elegant engineering.

Most homes receive alternating current, or AC, from the electrical grid.

Many electronic circuits, however, require direct current, or DC.

That means something must convert one into the other.

The transformer is usually the first step.

As we learned last week, the transformer can safely increase or decrease voltage while providing electrical isolation.

A household outlet may provide 120 or 240 volts AC, depending upon where you live.

The electronic circuit inside a radio may require only twelve volts.

A transformer performs the first part of that job.

The next step belongs to the rectifier.

A rectifier allows electricity to flow in only one direction.

Early electronic equipment often used vacuum-tube rectifiers for this purpose.

Later designs replaced them with semiconductor diodes.

Regardless of the technology, the goal remained the same.

Convert alternating current into direct current.

The result, however, is not perfectly smooth.

Instead, the voltage resembles a series of hills and valleys.

That is where another familiar component enters the story.

The capacitor.

Remember our discussion about capacitors acting like buckets of electricity?

Inside a power supply, capacitors fill in those valleys.

They store energy when the voltage rises.

They release that stored energy as the voltage falls.

The result is a much smoother DC output.

One simple component performs a remarkably important task.

Many modern power supplies go one step further.

They regulate the output voltage.

Whether the incoming power fluctuates slightly or the electrical load changes, the regulator attempts to keep the output steady.

Stable voltage means stable electronics.

Computers appreciate stable voltage.

Radios appreciate stable voltage.

Nearly every electronic circuit performs better when supplied with clean, consistent power.

Electronic Archaeology Note

One of the things that fascinated me when I first studied electronics was discovering that a power supply was not just a transformer.

It was an entire system.

Each component performed one specific job.

The transformer changed the voltage.

The rectifier changed AC into DC.

The capacitors smoothed the output.

The regulator maintained stability.

Separately, they seemed simple.

Together, they quietly powered nearly every electronic device I ever worked with.

That realization changed the way I looked at electronics.

Instead of isolated components, I began seeing complete systems.

Power supplies have evolved dramatically over the decades.

Older equipment often contained large, heavy transformers operating directly from household line frequency.

You could feel their weight the moment you picked up the equipment.

Modern switching power supplies operate at much higher frequencies.

Their transformers are dramatically smaller.

They are lighter.

More efficient.

Often far more complicated.

Despite the differences, both designs accomplish the same basic objective.

Deliver the correct power safely and reliably.

Power supplies also remind us that electronic equipment is only as good as the electricity feeding it.

Poor power causes strange problems.

Voltage spikes can damage components.

Voltage drops can cause unpredictable behavior.

Electrical noise can interfere with sensitive circuits.

Good power supplies exist to protect equipment from many of these problems while delivering the electricity the circuit actually needs.

That is why engineers devote so much attention to power supply design.

If the power is unstable, everything connected to it may become unstable as well.

Electronic Archaeology is about understanding how the pieces fit together.

The power supply is one of the first examples where we can finally see multiple lessons working together.

Electricity.

Magnetism.

Induction.

Transformers.

Diodes.

Capacitors.

Regulation.

Each lesson has been preparing us for this point.

The individual components no longer stand alone.

They become a functioning machine.

That is how real electronics works.

Not as isolated parts.

But as complete systems.

Next week we will begin exploring one of the most important inventions in communications history.

The vacuum tube.

For nearly half a century, it amplified voices, transmitted radio signals, powered radar systems, and helped build the first electronic computers.

Electronic Archaeology is finally arriving where many of us first became fascinated with electronics.

If this work helps you understand what’s happening, help me keep it going: https://www.patreon.com/cw/WPSNews

For more from Cliff Potts, see https://cliffpotts.org

References

Horowitz, P., & Hill, W. (2015). The Art of Electronics (3rd ed.). Cambridge University Press.

Encyclopaedia Britannica. (2025). Power supply. Encyclopaedia Britannica. https://www.britannica.com/technology/power-supply

U.S. Department of Energy. (n.d.). Fundamentals Handbook: Electrical Science. U.S. Department of Energy.

Capacitors | Electronics #4

In this video we will cover capacitors - what are they, what do they do and where do you use them.

#STM32World #Electronics #Capacitors

https://www.youtube.com/watch?v=FySp7jrzLWU

Hey #electronics .
Can I merge decoupling #capacitors ?
Pictured: 3 1µF caps in parallel.
One for VCC
One for AVCC
One is a filter for the power supply

It feels like they are all doing the same job and occupying space for no reason. What am I doing wrong?

#askfedi #hacking

🔌🤖 Oh great, another #podcast about #circuits, because clearly what the world needs is more talk about #resistors and capacitors! 🎧 Meanwhile, Michał Zalewski, aka lcamtuf, is apparently so #electrifying that you'll need a surge protector just to handle his #insights. ⚡✨
https://theamphour.com/725-the-secret-life-of-circuits-with-lcamtuf-michal-zalewski/ #technology #capacitors #HackerNews #ngated

Ceramic capacitor voltage sensitivity.

I looked up a Samsung 1206 22uF 25V X5R capacitor on their website.

Huge variation in capacitance against voltage. At the rated voltage the capacitance goes down by 90%.

Way more than I ever imagined! Would make a good VCO!

#capacitors #ceramic #electronics

How #chemists turned #bourbon waste into #supercapacitors
Hydrothermal carbonization can directly convert #stillage into hard or #ActivatedCarbon. Cossio & Guzman used activated carbon as #electrodes, creating double-layer #capacitors by putting liquid electrolyte between them. Proof-of-concept devices were able to store as much as 48W/kg. Built a hybrid device, with one activated carbon electrode and one hard carbon electrode, stored as much as 25 times the energy per kg
https://arstechnica.com/science/2026/03/how-chemists-turned-bourbon-waste-into-super-capacitors/

Dyson Vacuums and the Curse of Cooked Capacitors

https://fed.brid.gy/r/https://hackaday.com/2026/04/26/dyson-vacuums-and-the-curse-of-cooked-capacitors/

New video! Recapping the Amiga 3000T power supply.

YouTube: https://youtu.be/uKZePkkBd9g
PeerTube: https://makertube.net/w/rSCTC3Ddwsij2vukLprWe1

#Amiga #Amiga3000T #Amiga3000 #A3000T #Commodore #Restoration #PSU #PowerSupply #Recapping #Capacitors #Replacement #RetroComputing #VintageComputing #RareCommodore

Merry Christmas everyone! 🎄
I can finally check that this old Frako is just fine!
#capacitors

Oddly consistent corrosion: every 16-volt electrolytic in the device, plus one 25-volt. All the others were fine (after about 44 years). Or alternatively, all but one of this brand. There doesn't seem to be corrosion anywhere else, so it's probably not flux residues; but would all these have leaked or is it something to do with the metal itself?

Anyway, this is just tidying visible problems; don't know what's functionally wrong yet.

#capacitors #electronics #repairs

A very informative video on the improvement of sound quality of (professional) audio equipment with capacitors.

This knowledge can also be used in improving the tone of my Bass Guitar which suffers from a 3-6dB loss of signal on the third string (D string)

#music #capacitors #electronics #audio #interfaces #PA #pedals #bass #Joyo #passive #active #circuit

https://www.youtube.com/watch?v=fp0CvYj8n8k

I knew of two types of capacitor that had the right to their own symbol, but this 1939 manual has six pages of symbols corresponding to different types.

#capacitors #79 #systemsThatMatter

Just in: the long awaited 1937 sequel to the 1927 bible on capacitor production by Philip R. Coursey that I posted a while ago. Even more details, materials and production methods, but now zooming in on electrolytic capacitors. I didn't realize Coursey was the technical director of Dubilier, the first commercial manufacturer of capacitors, which I believe is still in business 105 years after it was founded.

#capacitors #electrolyticCapacitors #Dubilier #79 #SystemsThatMatter

Very timely arrival of what must be the bible on the history and materiality of capacitors, surprisingly rare, over 500 pages with more than 2000 references, published in 1927 when capacitors were high-tech. With many pictures of workers in the mica mines in India and the ladies back home who manufactured all those capacitors that kept the empire running.

#PhilipCoursey #Condensers #Capacitors #MediaArchaeology #79 #SystemsThatMatter

There have a vertical linearity issue on this CRT I picked up last weekend. It's a Magnavox "Computer Monitor 80" with no model # on the case anywhere, but I believe it's a Philips BM7500-series, or so.

(See the bottom 3-4 lines of text vs the rest of the text on screen - vertically squished.)

Here is the service manual as close as could be found,

https://archive.org/details/PhilipsBM75xxServiceManual/mode/2up

Can anyone tell from the schematic if there is a V.LIN pot on the board somewhere that I would find upon opening the unit? I'd like to get it adjusted and use it.

If it's a caps issue, I wonder how many would need to be replaced to get it back to snuff? This display was manufactured in late 1986.

#CRT #monitors #repair #AppleII #vintagecomputing #retrocomputing #fix #servicemanual #Magnavox #display #glitch #capacitors #repair #help #techhelp #TV

I'm designing a small circuit board which will have an STM32 microcontroller.

One document from STMicro says that the part must have two capacitors to filter the power supply, a 'ceramic' cap at 100nF, and a 'chemical' cap at 4.7uF.

Another document says they should both be ceramic caps, and the Nucleo64 evaluation board (sold by STMicro) uses ceramic caps for both.

Should I bother using a different cap for the larger value? If so, what qualifies as a 'chemical' capacitor, just electrolytics?

#Electronics #Capacitors #SchematicDesign

I've done my homework! 💪

#electronic #tinker #DIY #capacitors

This period was a nightmare for technical persons building computers. At that point in time I was building computers with a frequency of about 6 to 12 per day. The operating systems were put in afterwards.

Imagine the following nightmare scenario; at the certain point in time within the period of guarantee client calls with the message that the computer just stops working. The client has done everything that's needed to protect it; UPS, grounded outlets, ground resistance between .5 ohms and 1.2 ohms
Good UPS APC were good ones at that point in time.

Computers come in and after a while it's easy to see what happened because all the Elco's were dead, all of them!

#electronics #parts #capacitors  #chemistry #physics

The massive capacitor failure of 2K2

https://www.youtube.com/watch?v=rSpzAVpnXo4

#electronics #parts #capacitors #chemistry #physics

The capacitor plague of the early 2000s.

The Asianometry YouTube channel picks apart the story about this painful time. I had equipment fail because of this .

https://www.youtube.com/watch?v=rSpzAVpnXo4

#china #capacitors #electronics

Synth DIY component basics: capacitors

https://makertube.net/w/vQWeCK9y6s8i4maR6v1sBR

Basic Electronics for the Amateur Radio Operator: What You Need to Know for Your Technician License

1,003 words, 5 minutes read time.

If you’re preparing for the Amateur Radio Technician License Exam, understanding basic electronics is a must. While you don’t need to be an electrical engineer, the exam includes fundamental concepts like Ohm’s Law, circuits, components, and RF safety. This guide will walk you through the essential topics, ensuring you’re ready for the test and your first steps as a ham radio operator.

Understanding Electricity: The Basics for Amateur Radio

Electricity is the movement of electrons through a conductor, like a wire. Three key electrical properties define how electricity behaves:

• Voltage (V) is the force that pushes electrons through a circuit. It’s measured in volts (V).
• Current (I) is the flow of electrons, measured in amperes (A).
• Resistance (R) opposes the flow of electricity and is measured in ohms (Ω).

These three are tied together by Ohm’s Law, a fundamental equation in electronics:

V=I×R

This means if you know any two values, you can calculate the third. Understanding this equation is critical for both the exam and real-world troubleshooting.

Direct Current (DC) vs. Alternating Current (AC)

Electricity comes in two forms:

• Direct Current (DC) flows in one direction. Batteries and solar panels produce DC.
• Alternating Current (AC) changes direction many times per second. Household electricity is AC because it’s more efficient for transmission over long distances.

For amateur radio, most equipment runs on DC power, but you’ll also need to understand AC because radio signals are alternating currents that oscillate at high frequencies.

Essential Electronic Components and Their Functions

Several key electronic components appear on the Technician Exam. Here’s what they do:

• Resistors limit current flow.
• Capacitors store and release energy, often used in filtering circuits.
• Inductors store energy in magnetic fields and are important in tuning circuits.
• Diodes allow current to flow in only one direction, useful in rectifier circuits that convert AC to DC.
• Transistors act as switches and amplifiers in radio circuits.

Understanding these basics helps you answer questions about circuit behavior and troubleshooting.

Series and Parallel Circuits

Circuits are made up of components arranged in either series or parallel:

• In a series circuit, current flows through all components one after another. The same current passes through each, but the voltage is divided.
• In a parallel circuit, components share the same voltage, but the current divides among them.

For the exam, you should know how voltage, current, and resistance behave in each type of circuit. For example, total resistance in a series circuit is the sum of all resistances, while in parallel circuits, total resistance is lower than the smallest individual resistor.

Basic AC Concepts and Frequency

Radio waves are AC signals that oscillate at different frequencies. Frequency (f) is measured in hertz (Hz) and tells us how many times per second the wave changes direction. One kilohertz (kHz) is 1,000 Hz, and one megahertz (MHz) is 1,000,000 Hz.

Ham radios operate in different frequency bands, such as:

• VHF (Very High Frequency): 30 MHz – 300 MHz (e.g., 2-meter band)
• UHF (Ultra High Frequency): 300 MHz – 3 GHz (e.g., 70-centimeter band)

Higher frequencies allow for shorter antennas and are good for local communication, while lower frequencies travel further.

Modulation: How We Send Information Over Radio Waves

Modulation is how a radio wave (carrier wave) carries information. The Technician Exam covers three main types:

• Amplitude Modulation (AM): The signal strength (amplitude) changes with the voice signal.
• Frequency Modulation (FM): The frequency of the wave changes to encode information. FM is more resistant to noise and is commonly used in VHF and UHF bands.
• Single Sideband (SSB): A variation of AM that uses less bandwidth and is more efficient for long-distance communication.

Knowing these helps when selecting modes for different types of contacts.

Power, Batteries, and Safety

Most ham radios run on 12V DC power sources, such as batteries or regulated power supplies. It’s important to understand:

• Battery safety: Overcharging or short-circuiting batteries (especially lithium-ion) can be dangerous.
• Fuse protection: Many radios have built-in fuses to prevent excessive current draw.

Another key topic on the test is RF exposure safety. High-power transmissions can generate strong radio frequency (RF) radiation, which may cause health risks. To minimize exposure:

• Maintain a safe distance from transmitting antennas.
• Use the lowest power necessary for effective communication.
• Follow FCC RF exposure limits for your frequency and power level.

Ohm’s Law in Real-World Ham Radio Applications

A common exam question might involve calculating current or voltage using Ohm’s Law. For example:

Question: If a radio operates at 12V and draws 2A of current, what is the resistance?

Using Ohm’s Law:

Understanding these calculations can help with troubleshooting and designing circuits.

Final Thoughts: Studying for the Exam and Beyond

The Technician License Exam covers these topics, but learning electronics doesn’t stop there. Once licensed, you’ll continue exploring concepts like antenna design, signal propagation, and digital communication.

Great resources for studying include:

• ARRL’s Technician Class License Manual: The official guide with explanations and practice questions.
• HamStudy.org: Free practice tests and flashcards.
• QRZ.com Practice Exams: Simulated tests with real exam questions.

By mastering these basic electronics concepts, you’ll be well on your way to passing the exam and starting your journey in amateur radio. Keep practicing, get hands-on experience, and soon, you’ll be making contacts on the air!

D. Bryan King

Sources

• American Radio Relay League (ARRL) – Official Site
• FCC Amateur Radio Service – Licensing and Regulations
• QRZ.com – Amateur Radio Callsign Database
• HamStudy.org – Exam Prep and Study Tools
• Electronics Tutorials – Basic Circuit Theory
• RadioReference.com – Frequency Database and Scanner Information
• AMSAT – Amateur Radio Satellites and Space Communications
• DX Engineering – Ham Radio Equipment and Resources
• MikroE Learn – Electronics and Circuit Design Tutorials
• Radio Society of Great Britain (RSGB) – Ham Radio Resources
• Arduino – Microcontrollers and DIY Electronics for Ham Radio
• eHam.net – Amateur Radio News, Reviews, and Forums

Disclaimer:

The views and opinions expressed in this post are solely those of the author. The information provided is based on personal research, experience, and understanding of the subject matter at the time of writing. Readers should consult relevant experts or authorities for specific guidance related to their unique situations.

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#ACVsDC #am #AmateurRadio #amateurRadioEducation #amateurRadioTraining #antennaTheory #ARRLStudyGuide #basicElectronics #beginnerHamRadio #capacitors #circuits #current #diodes #electricalComponents #electronicsBasics #examPrep #FCCExam #FM #hamExam #hamLicense #hamOperator #hamRadio #hamRadioBands #hamRadioBeginner #hamRadioComponents #hamRadioEquipment #hamRadioOperator #hamRadioStudy #HamRadioStudyGuide #HamRadioTraining #hamStudyGuide #inductors #modulation #OhmSLaw #powerSupply #radioBroadcasting #radioCommunication #radioFrequencies #radioFrequency #radioFundamentals #RadioLicensing #radioSignals #RadioTechnology #radioTransmission #radioWaves #resistance #resistors #RFExposure #RFSafety #SSB #technicianClass #TechnicianLicense #transistors #UHF #VHF #voltage

I read this headline, and the first thing I thought was "oh hey, I wonder what old radios they recapped and fixed! I would watch that! They have awards for that, though? 🤔 "

#hamradio #capacitors #recapping

Finished #soldering. What I learned so far: l should clean between soldering #SMD components and #throughhole ones. I should leave enough space between the SMD components. I also dislike 0806 #resistors, better get some in 1206 size. The #capacitors were okay.
I tried it out with a square and a triangle wave as two inputs, connected through #potentiometers on a mini #breadboard and looked at the #oscilloscope
#diyelectronics #electronics #diysynth

2/ This is why I have never been a fan of Linux, people should be writing their own OSs 😜

As an aside, I found this #USENET thread with some familiar names from 1987 about porting Minix to the Atari - I assume that would have been the ST then.

https://www.linux.co.cr/unix-source-code/review/1987/0108.html

#DEC #Digital #PDP11 #LSI11 #Minix #Linux #OperatingSystems #Decent #Capacitors #USENET #Atari #AtariST #RetroComputing

1/ Just because, here's my LSI-11 desktop - It works, they used much better capacitors in those days.

Way back when, the LSI-11 was often used to teach people Operating Systems and Compiler Design, and in my CS degree in 1986 we'd fiddle with MINIX on these things, and deal with re-writing different low-level UNIX things. Life was much easier with only 50 instructions to work with.

#DEC #Digital #PDP11 #LSI11 #Minix #Linux #OperatingSystems #Capacitors #USENET #Atari #AtariST #RetroComputing

⚡Proper decoupling practices, and why you should leave 100nF behind

https://codeinsecurity.wordpress.com/2025/01/25/proper-decoupling-practices-and-why-you-should-leave-100nf-behind/

#electronics #makers #capacitors #technology

Of tens or maybe even around hundred Raspberry Pis that I repaired and saved from #ewaste - today I met the first one with a shorted capacitor.

My first ever shorted cap.

WOW.

#electronics #electronicsrepair #raspberrypi #ifixit #repair #capacitors

turns out this awesome little 65W #charger doesn't handle 400+ volts very well. no over-"provisioned" #capacitors here?

I do want to say one thing: aside from the capacitor plague era, components have been reliable way past the expected time manufacturers thought those computers would be used. The parts that are less reliable only started failing in numbers after over two decades and we're now four decades since the mid-1980s.

So yeah, I'll be mocking RIFA caps, mt RAM, early SIDs, TED chips and PLAs, but even these gave us at least a couple of decades of use. Even VARTA batteries stayed non-destructive for the same amount of time.

Anyway... Did you check your old stuff if caps or batteries have leaked recently? You probably should.

#retroComputing #capacitors #VARTA

Non-réparation d'un Sony EV-S35 (Video8)

https://video.latavernedejohnjohn.fr/w/x5G9knaKMwD7kj9CMcgqkm