My wife just realized that all my 'lectronics can actually help her - Page 1
Forum section: electronics / general

author: duckduck
author_rank: Frequent Contributor
timestamp: May 29, 2020, 09:02:00 pm
content: Wife asks me to feel her forehead because she thinks she might have a fever. "I might have the 'rona!" No, she does not. Her forehead feels fine. "We don't have any working thermometers and who knows where all of batteries are?" she says. I tell her that as part of my new 'tronics hobby that I have organized all of the batteries in this little bin. I put the thermometer on my bench and I soon realize that the thermometer's little CR1225 has turned slightly negative, so it is toast. We don't have a replacement, so I use my DC power supply and little grippers to supply 3.0 V to the battery leads on the thermometer and it lights up and beeps. I hold the leads while she checks her temperature: 97.3 degrees F (36.3 degrees science). "Oh, thank God! I thought I was going to be hooked up to a ventilator for sure!" She looks over the bench and I can tell that she realizes that this 'lectronics stuff can actually come in handy.Still struggling to demonstrate the great utility of the trials motorcycle and electric guitars.

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 29, 2020, 09:35:04 pm
content: Quote from: duckduck on May 29, 2020, 09:02:00 pmIf there's only one cell, what could have given it a reverse charge?

author: pickle9000
author_rank: Super Contributor
timestamp: May 29, 2020, 10:46:38 pm
content: So you think you can wrangle that realization into some new tools for the test bench?

author: Tom45
author_rank: Frequent Contributor
timestamp: May 30, 2020, 01:09:33 am
content: To quote Red Green: If the women don't find you handsome, at least they will find you handy.

author: babysitter
author_rank: Frequent Contributor
timestamp: June 03, 2020, 07:17:15 am
content: Tell her if you can get a big enough lab, you might even build her a ventilator..

author: duckduck
author_rank: Frequent Contributor
timestamp: June 05, 2020, 06:08:52 pm
content: Quote from: NiHaoMike on May 29, 2020, 09:35:04 pmI don't know.I googled this phenomenon and read that there's a theory that other batteries can "push" a battery negative. It seems to me that I find "negative" batteries in devices with a "soft" power switch more often than in devices with a power switch that breaks the circuit with the batteries. My gut feeling says that "negative" batteries are correlated with a long, low-current drain on the battery. I certainly have some "undead" batteries in my bucket-o-dead-batteries. I may just tape/solder a 100k R to a few batteries that are merely too low to power the super-low-cost electric motors in Junior's toys and then check them a few weeks later to see if they have joined the dark side.The "negative" battery is a CR1225 lithium cell (3 V nominal) and it was in a thermometer with a "soft" power switch. "58" has been printed on the back of that cell.N.B.: I'm one of the "haters" from the "I hate batteries" thread (https://www.eevblog.com/forum/chat/i-hate-batteries/msg3002444/#msg3002444). Would I really prefer to have a mains-powered thermometer? Even if it were double-galvanically isolated, triple-insulated, and UL listed I would still not allow my family to use it, so batteries win again.Might be nice to get a thermometer that uses 3xAA (https://www.welchallyn.com/en/products/categories/thermometry/oral-axillary-rectal-thermometers/suretemp-plus-692.html), but for US$500 I'd just as soon buy a FLIR so I can see how I've miswired my latest project...EDIT: Henli Max batteries are made by YuFeng Electrical (http://en.czyufeng.com/).Quote