Search found 1783 matches

by Externet
Sat May 05, 2018 4:36 pm
Forum: General Discussion
Topic: To evaluate performance of used 18650 cells...
Replies: 22
Views: 4456

To evaluate performance of used 18650 cells...

A bunch of old, used, salvaged lithium cells of unknown capabilities. Need a load scheme to evaluate their condition. Like loading them at a certain current load for 1 minute; another load for 10 minutes, another for one hour. Measuring the voltage at end. Perhaps checking voltage recovery after a c...
by Externet
Fri May 04, 2018 5:24 am
Forum: General Discussion
Topic: Typical 0.1 μF bypass capacitor value...
Replies: 4
Views: 2072

Typical 0.1 μF bypass capacitor value...

Most data sheets recommend 0.1μF bypass capacitors next to power IC pins. They smooth any sagging of the supply for the current the ICs draw in normal operation, and absorb transients generated elsewhere in the circuits. What if that capacitor value is raised; would it be 'better' or non-detrimental...
by Externet
Sun Apr 22, 2018 7:15 am
Forum: General Discussion
Topic: Aftermaster
Replies: 5
Views: 1996

Re: Aftermaster

Digital audio processing does wonders; but as soon as television/film producers find out that a gadget can improve the intelligibility, they will insist on raising the noises and distorted electric guitars they call 'music' background to make it worse. You cannot fix stupids abusing from sound effec...
by Externet
Thu Apr 12, 2018 7:27 am
Forum: Up For Grabs
Topic: Wanted: A couple of party clickers...
Replies: 9
Views: 2043

Re: Wanted: A couple of party clickers...

Got them :grin: (listed as dog trainers, not as party favors any more) They have to be cheap as last only few days in seawater before rusting...
If they were all snappy plastic would be a find !
by Externet
Thu Apr 12, 2018 7:17 am
Forum: General Discussion
Topic: Need Some Feedback Please...
Replies: 9
Views: 3696

Re: Need Some Feedback Please...

Clarity is important to teach.
Title could be 'Need some feedback about teaching online'.
All initial use of abbreviations and acronyms explained on a side column help novices.
by Externet
Thu Apr 12, 2018 7:06 am
Forum: General Discussion
Topic: Detecting a magnet... from a distance.
Replies: 23
Views: 5689

Re: Detecting a magnet... from a distance.

Hi John. So far I reached a 3 metre distance detection, with a 39000 turns coil. Ideal would be at least 50 metres. Perhaps am lacking mechanical dimensions (length) for the coil core bar. :sad: And refuse to spend too much $ for experimenting. Whenever you find how they detected the sun's magnetism...
by Externet
Sat Mar 10, 2018 8:32 am
Forum: Up For Grabs
Topic: Wanted: A couple of party clickers...
Replies: 9
Views: 2043

Re: Wanted: A couple of party clickers...

Thanks, dacflyer. Those are perfect. Somehow the ones I found before were battery operated. These are the real thing, mechanical snap.
Already in my list, for the next time I go to the 'city' with pet stores !
by Externet
Fri Mar 02, 2018 9:47 am
Forum: Up For Grabs
Topic: Wanted: A couple of party clickers...
Replies: 9
Views: 2043

Re: Wanted: A couple of party clickers...

Thanks, dacflyer. Found only electronic trainers. No mechanical :cry:
by Externet
Sun Feb 18, 2018 8:24 am
Forum: Up For Grabs
Topic: Wanted: A couple of party clickers...
Replies: 9
Views: 2043

Re: Wanted: A couple of party clickers...

Thanks, CeaSaR. That will do it !
And will save that site :smile:
by Externet
Sat Feb 17, 2018 4:34 pm
Forum: Up For Grabs
Topic: Wanted: A couple of party clickers...
Replies: 9
Views: 2043

Wanted: A couple of party clickers...

Hi. Any condition, ugly, rusty, from behind spider webs,... the one you stole from a kid that drove you crazy. Ebay has them at 'collector's prices; the dozen bag at the 99 cent store is not available any more. It is to test sound propagation. Will trade with hard to find IC or other parts. Make you...
by Externet
Sat Feb 03, 2018 8:17 am
Forum: General Discussion
Topic: Detecting a magnet... from a distance.
Replies: 23
Views: 5689

Re: Detecting a magnet... from a distance.

A good portion of noise could be erased by doing it differentially if in noisy environments. That is two sensors to reject common mode.
by Externet
Thu Feb 01, 2018 9:49 am
Forum: General Discussion
Topic: Detecting a magnet... from a distance.
Replies: 23
Views: 5689

Re: Detecting a magnet... from a distance.

:!: Yes, it is very real :!:
by Externet
Thu Feb 01, 2018 8:09 am
Forum: General Discussion
Topic: Detecting a magnet... from a distance.
Replies: 23
Views: 5689

Re: Detecting a magnet... from a distance.

Hi John. I talked to the developer/inventor of that expensive chip yesterday. He suggested trying first with the $30 ones from his company, as a way to evaluate if the expensive one would justify the results/needs/cost. I ordered a 10Km coil of AWG 40 before jumping to the modern sensors; will see n...
by Externet
Wed Jan 31, 2018 5:22 pm
Forum: General Discussion
Topic: Detecting a magnet... from a distance.
Replies: 23
Views: 5689

Re: Detecting a magnet... from a distance.

Hi John. That is exactly the plan. So far.
Because ----> https://www.amazon.com/TMR9001-Ultra-hi ... ometer+tmr
:shock:

Yes, iron core can work as well as mumetal.
by Externet
Sun Jan 28, 2018 6:47 am
Forum: General Discussion
Topic: Detecting a magnet... from a distance.
Replies: 23
Views: 5689

Detecting a magnet... from a distance.

Hi. Let's raise a bit the activity here... A magnet slowly spins in the next room. Or house. Or block. Detecting its presence will depend - on the field strength of the magnet, - the sensitivity of the sensor, - the gain of the amplifier, - and perhaps something else. What method would you implement...