News for hackers. Stuff that matters.

A comment on Everything with a battery should have an off switch. Parent comment

Re:Everything with a battery should have an off switch by bombcar on Monday May 09, 2022 @09:04AM (#31313528)
Since scales inherently involve putting weight on them it should be possible to use that weight to push down a plunger generating enough electricity to run for the weigh-in.

A spring would then reset it for the next time.

[ Parent | on HN ]
Re:Everything with a battery should have an off switch by BenjiWiebe on Monday May 09, 2022 @09:58AM (#31314054)
If there's a plunger resisting the scale going down to harvest energy, that would prevent all the force from being on the load cell, giving you incorrect readings.
[ Parent | on HN ]
Re:Everything with a battery should have an off switch by shkkmo on Monday May 09, 2022 @10:52AM (#31314800)
Not if the plunger rests on the load cell. Then plunger just captures the work done as it is compressed, it doesn't reduce the force that passes through it (once at equilibrium.)
[ Parent | on HN ]
Re:Everything with a battery should have an off switch by hundchenkatze on Monday May 09, 2022 @10:45AM (#31314683)
Couldn't you subtract the resistance of the plunger and display the adjusted value?
[ Parent | on HN ]
Re:Everything with a battery should have an off switch by ars on Monday May 09, 2022 @11:12AM (#31315129)
You can put the switch in between the plate and the force sensor.

Then all the force is on the sensor and is also a switch.

[ Parent | on HN ]