SAFELY Discharge a Capacitor (Don't Use a Screwdriver!)

Using a screwdriver is NOT safe. It can damage the capacitor (and possibly you). This method is easy and safe--though you should always be careful when working with electrical.

#diy #electrical #handyman

[TrapperAaron]

I wouldn't use my multimeter to discharge a cap. U could always hook it up to a light bulb. My grandpas test bench still has a 3 bulb resistance bank built in. You can swap out the incandescent bulbs for different wattages/resistances and has a set of switches that connect the bulbs in series or vairous configurations of parallel. One of my favorite jobs as a kid was bleeding down the cornicopia box of transformers, caps, and components from all manner of stripped-down appliances and equipment.

[bananaehgs]

I’m gonna go around touching every bare wire and terminal I can find

[kevinmalec]

Contrary to other comments, I say this is safe, it's just slow. the meter's input resistance during dcv measurement will discharge the capacitor. don't do this with the meter on amps - the hrc fuse in the meter is more expensive than your time making or buying a faster discharge tool.

[ce]

An analog meter will discharge a capacitor. A digital can but takes a long time. A 1000 ohm resistor or incandescent bulb is best. It is up to you to do it safely.

[Actrealsurprised]

I’ve done hvac for 16 years and just stuck them to the unit on the ground. I had no idea you could do this. Learn something new every dau

[camforman]

Most dvms have an input resistance on the order of 1 to 10 megaohms. The cap in the video looks like a typical motor start capacitor which are on the order of 10 to w few hundred microfarads. So 100uF × 10M ohm = 1000 seconds ~ 13.3 minutes. This means that a cap that started at 150v will still take about 15 minutes to discharge. If the voltage is higher than 1500v it could damage the meter and still take an hour to discharge. So a lightbulb would be faster but still not high voltage safe. Then there are multi farad supercaps that even at 3v will weld to anything metal and take monthes to discharge this way, although safe to touch if your not whearing a ring...

[elgordo]

You can also use a insulated needlenose plier

[BeesKneesBenjamin]

Good video! It sure is safe to actively measure to see your capacitor is properly discharged. You can get a very nasty sting if you don't watch out!

The input impedance of your voltmeter is so high, it's gonna take a while to discharge though :-). Of course it is safe to do so, if it's not, the engineer did a poor job designing the front end of the meter. BUT it's easiest to just discharge it through a resistor. You can always measure afterwards if you want to be sure. I'm sure worst case the internal resistance of electrolytic capacitors is high enough to survive a complete short as well every now and then.

A good tip is to often incorporate a bleeder resistor when you use big capacitors, whenever you turn the device off, it will slowly discharge the cap. Ofcourse its not always ideal, but you see this in many oldskool powersupply designs.

Also, it is good practice to store capacitors with shorted terminals, then you know a 100% sure they're discharged :-). I do this mostly only with capacitors with screw terminals with a fat piece of copper wire.

[LR]

what brand hoodie is that. id be perky to if i was wearing it

[ronyerke]

My older brother used a light bulb to discharge a capacitor when we were kids. It got bright and dimmed pretty quickly, about 3 seconds. The filament's resistance slowed the discharge, but now I wonder if maybe he should have used multiple bulbs for more resistance.

[aureliosacchio]

What about dipping the terminals into saltwater? (In case you have no light bulb, let alone a resistor at hand.)
I mean maybe that's also not that hard on the cap and you can see from the bubbles when it's over. (Hmm, one of the terminals will be a bit oxidized though, right?)

[HVACLife]

Insulated screwdriver works just fine 😂

[JCR]

Great info here! Thank you for posting. 😊

[MaartenVanNuffel]

You should just use an oldschool lightbulb. The one with the wire

[honeybadgerrants]

We use to use the flash capacitor in a disposable camera to make a little "tazer" so yeah i kinda already know how to discharge a capacitor

[bradfader]

They do sell discharge devices specifically meant for caps. If all fails just use a garden hose

[sirgregoir]

We used to throw them to the Apprentice. Here catch, then we would all roll around laughing. Works everytime..!

[digital-experiance]

Hmm, what did she say? I was distracted by the headlights.
Sorry, had to do it.

[turboprintd]

I have a set of jumpers and a large 5k r resistor i use for dumping caps

[alanhurdle]

I am working on free energy, the real one. Thanks for helping. I bought a capacitor that was developed for an Rf system 5000k fraud. I am learning its values from kilo watts amp hours to the usage that an individual would use and even more! What they use it on. Storage is your time, your generation teaching the people who to make electricity will be easy how to wire it up you be able to do it. It is the holding cell that will be where the money is studied and play with the elements the periodic table focuses on in their information sections play with the heat section (kelvins) Mercury the elements follow up on it. A path way awaits you alway do for the good thank you for the video