How To Discharge Capacitors The RIGHT WAY | Build a DIY Capacitor Discharge Tool

[@klapaucjusz1]

I found this useful. But for novices it is also good to remember about the "one hand in the pocket" safety rule.

[@senselessinductor7921]

And just so we're clear, if you're a lefty like me, get used to using your right hand... (Left hand in the pocket right hand doing the deed) "Keep that current running as far away from your heart as you can." ;) *And if you're really scurred, get a pair of insulating gloves for fuch's sake! (I don't get near anything I know will kill me, with bare hands)

[@pbakai182]

Every other tutorial I've seen with a similar tool has the one alligator clip to Ground (I.E. the chassis) and the other end of the tool (usually a probe, or can be alligator clip) touching both leads of the Capacitor one after the other. Any reason why you don't do this method?

[@linusblom2]

I saw a youtuber who used a homemade discharger one end was a alligator clip and the other was a probe. He explained that you attach the alligator clip to ground and the probe to positive side of the capacitor but he also said that you can also attach the alligator clip to the negative side because negative side always goes to ground. So you can choose where you wanna clip it to.

[@xlivexevilx]

Thank you bro! I made one similar except I soldered my resistor to a screwdriver and the other ends used a wire and alligator clip. Thanks again!

[@TheToneGeek]

You're welcome!

[@bwl123]

When soldering the resistor, attach a crocodile clip next to the resistor to avoid heat damaging the resistor.

[@linusblom2]

I have seen on youtube that some attach the alligator to the multimeter probes and then use the probe on the capacitor so they can see the drop in real time rather than counting and measure after. This must be a more timesaver. So I wonder if it's safe to do it like that. And if not why wouldn't it be?

[@TheDestineyAngel]

I was thinking about making one of these. Thanks for sharing this tutorial. Other videos tend to use short circuit method as well as the sparks. yet you never really know what might happen to that 500V capacitor during the short. Thanks for showing us the resistance of the wires using the ohmmeter to show your process was valid. why did you discharge the capacitor if the voltmeter said it had low voltage anyways in the 10 mV range? The resistors at the top were for discharging?

[@TheToneGeek]

Thank you for your kind words! My brain sometimes stops working when the camera is rolling and I think I was trying to demonstrate the capacitor discharging even further.

[@gastube22]

On top of the good stuff in some of the other comments... You need something to add more rigidity and strength to the resistor section. Just using basic heatshrink isn't enough. For example, a rod or strip of suitable high-voltage insulating plastic placed alongside the resistor, that the wires are tightly secured to. Otherwise, there's a risk that, after some considerable handling, the solid wire at one (or both) ends of the resistor might fracture and break the connection. Then it wouldn't be effective - so as he advises at the end, always check the voltage on the capacitor again after discharging, to make sure it has been properly discharged. Further, be aware that, after discharging one capacitor, a different capacitor in the circuit, that still has some charge, might charge it up again. So again, as he hints at right at the end, when you think you are done discharging them all, check ALL the capacitors again, and repeat as necessary... Also, you should check that your voltmeter is working properly, both before AND after making any test measurement that your life could depend on.

[@TheToneGeek]

Thank you for the awesome suggestion. Thank you!

[@robertgrays8790]

Right. The one you don't check, is the one that gets you.

[@prodoverjeff2876]

My own discharge method usesyour way but I add a ceramic resistor, about 1000 ohms and my multimeter so I measure the initial voltage and watch the meter to see the gradual decrease.

[@keyofg2020]

Can anyone tell me how the determine the appropriate resistance range to use for the capacitor being discharged? I'm sure a 200V 2200µF capacitor would require a different resistance than a 35V 1000µF capacitor, yes? Does VW mean something different than just V?

[@Retro.Studio]

Beware of when twisting and cutting the left overs of the resistor, be sure they are not Sharp en comes like a needle out of the heatshrink. So be aware, this thing is double isolated or there is a change to grab it and kill you when discharge high voltage capacitors.

[@TheToneGeek]

ooff! THank you for the advice!

[@Retro.Studio]

The Tone Geek it's only a safety thing, but although a great video.

[@PLINKER]

Thanks I'm trying to learn a bit about working on amps but want to be safe!

[@fritzj6803]

I suggest using a 5 watt resistor to be on the safe side. A 5 watt resistor can dissipate more heat than a 1 watt resistor without melting, making it better for discharging a capacitor. A 5 watt resistor can also be rated for at least 2.5 watts of power dissipation, which is safer for discharging a capacitor.

[@TheToneGeek]

Great suggestion! Thank you for writing in

[@vaejoviscarolinanus]

Is it okay to measure the cap still attached to the circut before I try to discharge it? What setting should I put on the multimeter? I am trying to figure out what is causing my ST70 amp to get a faint Oscillating sound and hum .

[@stevec9669]

What resistor is good to discharge a microwave oven capacitor (2100v)? xxxk ohm, xx watt?

[@Asian_Connection]

You look like a master. Can you just point me in the right direction? I have a Mark Levinson no.27 amp. When I turn it on I heard a strong pop on the right speaker and then the unit went into protection mode. Even time I turn it on after that the power switch would pop back to off. Same result with all cables off with only power plugged in. The power light still lights, fuse is good. Can anyone give me some guidance?

[@grahambambrook313]

Pre-tin the back of the clip first for an easier joint and good solder fusion!!!!

[@robzecc]

This is a crazy dangerous way to do it!

[@thetheoryguy5544]

I usually have a clip to ground and one on end of the cap then discharge, never to both ends of the capacitor lol

[@MC-hx6nk]

@@thetheoryguy5544 That is only okay if one side has an earth reference. If your capacitor is floating (hypothetically) and charged to 500V, grounding one, let's say the more negative side, will leave 500V on the other (with reference to earth). If you then probe the other side, the first side will go -500V (negative 500V wrt earth). All danger still there, nothing happened to reduce the stored charge. You may well have been very lucky up until now that one side was technically connected to your other (earthed) probe - of course it only was made safe because you somehow did connect both side of the capacitor together (intentionally or not) and put the electrons and 'holes' back in their stables.

[@The_Absurdistt]

DO NOT PUT BOTH HANDS IN THE AMP when measuring voltage or discharging caps. This vid does show what NOT to do.... had to be said to protect people from misinformation.

[@racmusiccom]

So much bad information from self taught “professionals” that have no knowledge based in science and fact here in youtubeland.

[@jasonperez7811]

All one needs is common sense. Only idiots electrocute themselves. I'm a self taught electronics enthusiast and I often have both hands in the amp. Once of course I make sure the capacitors are discharged, which also implies that the amp is off and removed from power, I've never accidentally "shocked" myself, and anyone with common sense and a little bit of intelligence won't. Only idiots electrocute themselves. The world needs less idiots.

[@The_Absurdistt]

@@jasonperez7811 So only idiots electocute themselves? So does that logic dictate that most, if not all, legendary amp builders/modders are idiots as Steve Fryette, Dave Freedman, John Suhr, and many others have shared stories of potential near death experiences getting zapped while tooling around in amps. Please review your statement.....

[@jasonperez7811]

@@The_Absurdistt one word common sense. If they were wood workers they'd have fewer fingers. Anyone that is careful and cautious ⚠️ absolutely will not electrocute themselves unintentionally. Accidents occur when we, overconfident, skip steps. Anyone that doesn't discharge capacitors and then check that they're actually discharged and follow all safety steps WILL NOT get electrocuted. Cutting corners, being lazy, and not paying attention will get you killed and considering how easily avoidable it is. Anyone that does so is indeed an idiot. I'm sure, that after they shocked themselves they would agree at how stupid they had been.

[@robertgrays8790]

Idiots is an incorrect word to describe people that are electrocuted. I do agree the methods used in this video are unsafe, and the creator should have first gone into detail about electrical safety to protect those that work on capacitors and energized components holding electricity. To pre-emptively call shock victims that actually die idiots is heavily biased and disrespectful to front-line electrical workers that literally put their lives on the line every day to keep the bulk power system running reliably. Any number of reasons can be found as to why an electrical shock occurred, from an incorrect assumption about how the circuit , tools, or equipment works, to complancy or oversight in setting isolation boundaries, not using proper personnel electrical propection, to unknown conditions inside a circuit such as a rusted enclosure piece falling on 2 phases of a bus, or a protective relay failing to open the circuit in time.

[@ourclarioncall]

The more I watch amp videos the more I fear and respect electricity and am shocked (no pun intended) at how dangerous amps can be to use/work on. It’s tempting to just want to dive in a try things but a person really has to understand the hidden dangers. We can’t emphasise safety enough. Learn as much as you can, watch lots of videos, ask lots of questions, and remember before trying to work on amps “if in doubt , don’t”. If your not confident and don’t really know what your doing then don’t take risks, leave it to someone qualified /experienced. Peace

[@robertgrays8790]

The content creator did not include any mention of electrical safety. Performing this work without any protection can result in serious injury or death. For the content creator's liability protection, a disclaimer should be included in each video, especially since it's a DIY video. Holding a metal part being soldered directly without a table clamp or vice can result in skin burns, and you can lose your eye sight if spallering solder gets in your eye. Working with potentially energized circuits at high voltage should have Flame Resistant gloves for arc flash protection and voltage resistant gloves for shock protection until the circuit and components to be worked on are verified de-energized. The part or phase you don't check is the one that gets you. The voltage in this circuit had up to 600 volts, and he could have easily caused an electrical arc and blown up the capacitors in the camera's view waving the hand tools over it. Know and respect the minimum safe distance for preventing arcs. Safety should the first topic discussed, and repeatedly discussed during the video.

[@raykar2]

Why don't you tin your solder iron? Tin your wire ends? No flux? It may have been quite a bit easier.

[@utopia2112]

I think the solder had flux in the middle of it. Look closely at the spool.

[@oldspiced]

will that little resistor work on any size capacitor? apologies if you said it in the video i didnt watch whole thing XD

[@TheToneGeek]

Any size capacitor might be a stretch depending how many microfarads however for caps inside guitar tube amps you can be generally certain this resistor works well

[@xxtwnz2919]

That resistor would work in almost all cases of high voltage and high power (uF). It simply takes longer than a resistor with a lower value while also reducing the heat that needs to be dissipated.

[@jeanlawson9133]

Thanks 😎

[@Damaraja]

Thanks, man 🤙

[@frankhoxsey1177]

Great tutorial!

[@TheToneGeek]

Thank you!!

[@Tipp_Of_The_Mitt]

would it be better or safer to add a second resistor to this tool?

[@TheToneGeek]

I don't think it would matter adding another resistor or not. There isn't much current going through the caps like this so I am unsure the benefit. Do you have a thought of something I may not be thinking of?

[@MC-hx6nk]

It would be better! First you need to know that if you put two (like valued) resistors in parallel, the resistance will half. Secondly, (which is the bit I think you were getting at) it builds in redundancy - almost always a good thing when it comes to safety. Thirdly, with the current splitting between the two resistors in almost equal proportion (actually disproportion, but close enough), you can add up the resistor ratings and say your 1W single resistors are now rated at 2W with them combined. You can measure with a meter before and check if one of the resistors has failed. But even if it does (usually) go open while discharging, the lower (overall) resistance of the remaining one, won't break its own power rating. As a side note, two sets of parallel resistors in series with two more the same, gives the same overall resistance as any one of the four it is constructed from. Series - doubling, parallel - halving, takes you back to x1. Make sure to join them all together in the centre and then do all the lovely calculations for the failure modes. Hard to heatshink, I know ...but there are small ABS enclosures that can house all that. Maybe put some 4mm shrouded sockets on the outside, pull your VDE rated leads out of your multimeter and use those. Oh ...now I feel sorry for the little crocodile lead we need to feel proud of 😢

[@williambock1821]

Ok so WHAT is going to blow up the amp,exactly?

[@Stoney47]

What size resistor do you use? Or does it matter?

[@TheToneGeek]

I would use at least 1w 500v resistor

[@MC-hx6nk]

@@TheToneGeek What 500V resistor is that then? Besides resistance, the only other figure you need is its power rating. As you had the 47uF 500V capacitor in view, your 220K 1W rated resistor is at least momentarily working 10% above its rated power (please see, 'derating'). Electric shocks are serious enough to not be describing a video as 'the right way', when you seem to know little better yourself. Was your heatshrink rated at the same voltage as the wire? If there was any sharpness where you soldered, that will create a potential weak spot. The inbuilt circuit resistors are called bleed resistors or a bleed network. Depending on the capacitance and the voltage, you may use the same resistor, but you need also to be aware of time constant; the rule of thumb being 5RC (look it up if you don't know) will bring you to about 1% of the voltage you started at. It is also worth mentioning that capacitors can produce very high current discharging initially, they pose a significant threat if starting at mains or above (dependant on your country, I guess).

[@JP-gc5in]

You added text saying “Anything less than 20 volts should be discharged.” Don’t you mean anything greater than 20 volts should be discharged? What about a capacitor at 150 volts? Don’t discharge it? Seems like the wrong advice. Also you should add a comment saying not to horse around with high voltage capacitors unless you know what you are doing.

[@COG777]

It's a no brainer you clever dick

[@tomvaisar6331]

He meant: if it has less than 20V on volt meter = it's (considered) Discharged

[@weimaraner3240]

Caution: If you are working on any equipment with a HIGH voltage power supply (i.e. anything greater than 600V) this will not work. Get schematics, be able to read them and be aware of what you're working on before attempting to discharge the capacitors.

[@androidgameplays4every13]

WHy this will not work?

[@robertthompson5908]

Terrible soldering technique! Holding the part with your hand is a really bad way to solder. For one thing you’ll jiggle the part while the solder is cooling ( in a split second) which can create a bad joint. Secondly if a joint is hot enough to solder probably the heat will flow to your finger (again in a split second ) and you’ll get burned. Also, a wire with an alligator clip at one end and a probe of some sort at the other (you can make the probe simply out of a mail for example) will be more useful.

[@Brandon-youtube]

Do you have a light bulb current limiter?

[@TheToneGeek]

Not right now.. duck and cover 😎

[@KyleFalconer1]

The light bulb will light up in the event of a short, preventing the accidental destruction of whatever equipment you are working on. There are several videos on how to make one on KZbin.

[@ourclarioncall]

Just watched a video on “uncle Doug “ amp channel on making a simple enough safety device to protect the components in the amp , and also protecting you too. Two different methods , some use a high wattage bulb and others use a low wattage bulb. The light bulb lights bright and then dims in one method and the other method the light bulb only lights up when there is something wrong. I hunk there is pros and cons for both. Very interesting and worth researching for safety

[@colinellicott9737]

Nice vid - Thx. Ceramic resistors are preferable for this application, energy & heat being an issue, also the resistor chosen is proportional to the capacitor's values, so one tool is not appropriate for all capacitors. Your use of the tool did not follow your instructions for how to use the tool - Too quick/ two hands/ no post discharge V check.

[@nickhoenig822]

sure, teach people to stick both hands inside an amp. you're get someone hurt like this

[@paulwood1657]

Brilliant!!! Thanks for doing this one 😄👍

[@TheToneGeek]

So glad you found it first!! This one's for you 🍻

[@paulwood1657]

The Tone Geek I really appreciate it. You've got the best channel on KZbin 👍

[@JohnAdams-xc5yk]

You can buy a discharge pin for a few dollars

[@zoozolplexOne]

cool!!!

[@jkbish1]

nicely done

[@TheToneGeek]

Thank you!

[@g8sbs944]

OMG you are Soldering that wrong YOU SHOULD SOLDER THE WIRE ON THE INSIDE OF THE CROC CLIP

[@weenote]

nice amp

[@tomgiorgini9154]

you dont know what gage wire it is and you think you know what your doing, gotcha

[@sonnysilversmith2156]

You are driving me nuts!… get a frickn extra grips!

[@COG777]

Why not just short it with screwdriver your doing same with that wire anyway lol

[@TheToneGeek]

I hear the quick capacitor discharge can harm the cap.. Slow should be ok :-)

[@COG777]

@@TheToneGeek Oh I see. So does doing so with a wire slow down the discharge?

[@TheToneGeek]

@@COG777 wire + resistor in the middle, yes ⚡. Great question!

[@ourclarioncall]

First of all I’d like to say Thankyou , I really like the tone of this channel, so many guitar and amp channels I’ve watched recently are so full of cussing and vulgarity and it’s so off putting and out of context. If there is good content people will happily watch it. I have a question, but don’t expect an answer as I know you have a life and can’t engage with every comment , but possibly you or another person can explain I think I understand that the cap (that you discharge at the end with the resistor and alligator clips) has electricity inside it ? Or a charge ? I’m wondering where does it go ? I’m guessing it slowly leaves one end of the cap goes through the wire, through the resistor , then where does it go ? As my brain is telling me it should just go back into the cap again like going round in a circle , but obviously that’s not correct ! Thanks

[@ourclarioncall]

@@michaeltilley9119 thanks Mike , makes sense 🙂

[@chongshenchang9367]

First of all, you need to learn some soldering lesson.

[@TheToneGeek]

Thanks. How is my soldering in my latest videos?

[@chongshenchang9367]

@@TheToneGeek I never thought you would reply within few minutes to a five years old video. 😀😀😀 Thankyou...👍👍👍 Actually, that was a random comment..😁😁😁

[@TheToneGeek]

@@chongshenchang9367 I hope I made your day ❤️⚡