this post was submitted on 13 Feb 2024
39 points (95.3% liked)

No Stupid Questions

36151 readers
1215 users here now

No such thing. Ask away!

!nostupidquestions is a community dedicated to being helpful and answering each others' questions on various topics.

The rules for posting and commenting, besides the rules defined here for lemmy.world, are as follows:

Rules (interactive)


Rule 1- All posts must be legitimate questions. All post titles must include a question.

All posts must be legitimate questions, and all post titles must include a question. Questions that are joke or trolling questions, memes, song lyrics as title, etc. are not allowed here. See Rule 6 for all exceptions.



Rule 2- Your question subject cannot be illegal or NSFW material.

Your question subject cannot be illegal or NSFW material. You will be warned first, banned second.



Rule 3- Do not seek mental, medical and professional help here.

Do not seek mental, medical and professional help here. Breaking this rule will not get you or your post removed, but it will put you at risk, and possibly in danger.



Rule 4- No self promotion or upvote-farming of any kind.

That's it.



Rule 5- No baiting or sealioning or promoting an agenda.

Questions which, instead of being of an innocuous nature, are specifically intended (based on reports and in the opinion of our crack moderation team) to bait users into ideological wars on charged political topics will be removed and the authors warned - or banned - depending on severity.



Rule 6- Regarding META posts and joke questions.

Provided it is about the community itself, you may post non-question posts using the [META] tag on your post title.

On fridays, you are allowed to post meme and troll questions, on the condition that it's in text format only, and conforms with our other rules. These posts MUST include the [NSQ Friday] tag in their title.

If you post a serious question on friday and are looking only for legitimate answers, then please include the [Serious] tag on your post. Irrelevant replies will then be removed by moderators.



Rule 7- You can't intentionally annoy, mock, or harass other members.

If you intentionally annoy, mock, harass, or discriminate against any individual member, you will be removed.

Likewise, if you are a member, sympathiser or a resemblant of a movement that is known to largely hate, mock, discriminate against, and/or want to take lives of a group of people, and you were provably vocal about your hate, then you will be banned on sight.



Rule 8- All comments should try to stay relevant to their parent content.



Rule 9- Reposts from other platforms are not allowed.

Let everyone have their own content.



Rule 10- Majority of bots aren't allowed to participate here.



Credits

Our breathtaking icon was bestowed upon us by @Cevilia!

The greatest banner of all time: by @TheOneWithTheHair!

founded 2 years ago
MODERATORS
 

Can I Use my Multimeter to Test How Much Power my Appliance (TV) is Using?


I wanted to know if my TV actually uses only 50W of power.

If it's possible to use a multimeter to check, how do I do it and what should I avoid?

you are viewing a single comment's thread
view the rest of the comments
[–] [email protected] 10 points 10 months ago* (last edited 10 months ago)

This is tricky, as power is calculated as voltage x current. Measuring (or knowing) voltage is usually pretty straightforward. But accurately measuring current requires setting up the circuit so it flows through the multimeter (while set to whatever current measurement mode it has - usually "Amps A/C", or similar). However, this method isn't safe, or practical, for non-electricians to measure A/C appliances.

As someone else mentioned, you could buy a multimeter that has an "amp clamp" - effectively a non-contact way of measuring current. BUT, you need to be aware...

A typical appliance's cable will have both active and neutral wires inside the outer layer of insulation. Current flows through a circuit - up one wire and down the other, if you will. So an amp clamp can only measure the current on one of those wires. If you were to measure both at once (ie. clamp the whole cable), the readings in each direction will cancel each other out. You'll measure zero net current. The only way is to cut the outer insulation and clamp a single wire inside.

I would absolutely NOT recommend this for an A/C appliance. The possibility of accidentally cutting through the insulation of one of the inner wires, combined with the possible death of the person handling it afterwards, should make this a non-starter.

Your safest options for ANY A/C powered appliance are to either:

  1. rely on the manufacturer's label; or
  2. buy a smart plug that measures the current for you.

There's many, many brands for the latter available, and most are really quite affordable.

Edit: as another commenter said, you could possibly buy a short extension lead that splits the wires out for you, but now you're buying a non-standard extension lead and (possibly) a new multimeter, all to validate what's on the appliance's label.

A $20 smart plug with current measurement will still be your cheapest and safest option.