284

I hate this scale, it says low battery and shuts off after just 3 months of sitting in the drawer. It infuriates me that there's still a lot of energy in the battery, I can use that in remote controls with no issues

If there's enough battery to say "low battery", then there's enough battery to show the measurements!

you are viewing a single comment's thread
view the rest of the comments
[-] Thorry84@feddit.nl 288 points 2 weeks ago

That's because of the way these scales work. They use a material that deforms under stress and when it deforms the resistance changes. By putting current through this material and measuring the voltage drop, it can be mapped to how much stress the material is under and thus how much weight is on the scale.

This is a pretty roundabout way and has a lot of caveats, but it is very cheap. So cheap scales always work this way. That's why they aren't super accurate and have deviations depending on things like temperature. Another big downside is any permanent deformation ruins the calibration, giving incorrect results. That's why you never put more weight on kitchen scales than it says, it will break them.

The issue you are running into is the way it measures. It applies a very specific voltage and current in order to get the result. The lookup table it uses is only valid within a narrow range. When the battery voltage goes outside that range, it can no longer perform the measurement. Even though there's plenty of juice for things like the little processing chip and the LCD display. They don't need a lot of power and can do with low voltages. But it can no longer weigh anything so it just errors out with a low battery warning.

[-] thisguy1092@lemmy.world 44 points 2 weeks ago

Mighty informative, thank you

[-] Wizard_Pope@lemmy.world 15 points 2 weeks ago

Look up piezolectric materials if you wanna know more

[-] marcos@lemmy.world 5 points 1 week ago

The GP is not describing a piezoelectric scale. And you won't be able to find any piezoelectric scale that is anything similar to "cheap".

[-] Wizard_Pope@lemmy.world 3 points 1 week ago

Well which principle do the cheap ones operate on?

[-] Thorry84@feddit.nl 15 points 1 week ago* (last edited 1 week ago)

It's actually a plastic ribbon with a metallic foil in a zigzag pattern on top of it. It's extremely cheap and does a pretty good job. It usually sits on top of a metal bar that can deflect a tiny little bit.

You can read all about it here: https://en.wikipedia.org/wiki/Strain_gauge

The main effect is that the resistance depends on the geometry. So as that changes, the resistance changes as well.

load more comments (22 replies)
this post was submitted on 04 Nov 2024
284 points (89.7% liked)

Mildly Infuriating

35459 readers
1480 users here now

Home to all things "Mildly Infuriating" Not infuriating, not enraging. Mildly Infuriating. All posts should reflect that.

I want my day mildly ruined, not completely ruined. Please remember to refrain from reposting old content. If you post a post from reddit it is good practice to include a link and credit the OP. I'm not about stealing content!

It's just good to get something in this website for casual viewing whilst refreshing original content is added overtime.


Rules:

1. Be Respectful


Refrain from using harmful language pertaining to a protected characteristic: e.g. race, gender, sexuality, disability or religion.

Refrain from being argumentative when responding or commenting to posts/replies. Personal attacks are not welcome here.

...


2. No Illegal Content


Content that violates the law. Any post/comment found to be in breach of common law will be removed and given to the authorities if required.

That means: -No promoting violence/threats against any individuals

-No CSA content or Revenge Porn

-No sharing private/personal information (Doxxing)

...


3. No Spam


Posting the same post, no matter the intent is against the rules.

-If you have posted content, please refrain from re-posting said content within this community.

-Do not spam posts with intent to harass, annoy, bully, advertise, scam or harm this community.

-No posting Scams/Advertisements/Phishing Links/IP Grabbers

-No Bots, Bots will be banned from the community.

...


4. No Porn/ExplicitContent


-Do not post explicit content. Lemmy.World is not the instance for NSFW content.

-Do not post Gore or Shock Content.

...


5. No Enciting Harassment,Brigading, Doxxing or Witch Hunts


-Do not Brigade other Communities

-No calls to action against other communities/users within Lemmy or outside of Lemmy.

-No Witch Hunts against users/communities.

-No content that harasses members within or outside of the community.

...


6. NSFW should be behind NSFW tags.


-Content that is NSFW should be behind NSFW tags.

-Content that might be distressing should be kept behind NSFW tags.

...


7. Content should match the theme of this community.


-Content should be Mildly infuriating.

-At this time we permit content that is infuriating until an infuriating community is made available.

...


8. Reposting of Reddit content is permitted, try to credit the OC.


-Please consider crediting the OC when reposting content. A name of the user or a link to the original post is sufficient.

...

...


Also check out:

Partnered Communities:

1.Lemmy Review

2.Lemmy Be Wholesome

3.Lemmy Shitpost

4.No Stupid Questions

5.You Should Know

6.Credible Defense


Reach out to LillianVS for inclusion on the sidebar.

All communities included on the sidebar are to be made in compliance with the instance rules.

founded 1 year ago
MODERATORS