Re: Extech EX410A DVM Don't Buy

Liste des GroupesRevenir à e design 
Sujet : Re: Extech EX410A DVM Don't Buy
De : alien (at) *nospam* comet.invalid (Jan Panteltje)
Groupes : sci.electronics.design
Date : 07. Oct 2024, 08:25:27
Autres entêtes
Message-ID : <ve02d8$3n82$1@solani.org>
References : 1 2 3 4 5 6 7 8
User-Agent : NewsFleX-1.5.7.5 (Linux-5.15.32-v7l+)
On a sunny day (Sun, 06 Oct 2024 10:56:14 -0700) it happened Jeff Liebermann
<jeffl@cruzio.com> wrote in <cmd5gj12l7q8bqflsd6lcj9t6mr4feipnu@4ax.com>:

On Sun, 06 Oct 2024 06:04:58 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
>
On a sunny day (Sat, 05 Oct 2024 17:30:03 -0700) it happened Jeff Liebermann
<jeffl@cruzio.com> wrote in <ugj3gjp918lmu1b7fipb2vqe4a2kucgf5q@4ax.com>:
There are also consistence problems and matching issues with NiMH:
<https://eneloop101.com/batteries/eneloop-test-results/>
>
Wow, some test site.
>
Yes.  I find the best web sites when I'm looking for something else.
>
Eneloop looks good, oldest onces I have are AAA from 2010 ...
still going fine, some in remotes, one in an inside/outside temperature meter
I have a DCF radio-clock with eneloop too.
>
Will your DCF radio clock operate at 1.2VDC (or less) at the radios
"normal" current drain?  Actually, yours probably uses two cell in
series, so that should be 2.4VDC.

Nope, one big AA, using an Eneloop
Top left one:
 https://www.google.com/search?q=xiron+radio-controlled+-+DCF&client=firefox-b-e&sca_esv=7190e4524bdedbd5&tbm=isch

Runs for years on the eneloop
In use now for 20 years? displays room temperature too.



The better NiMH cells provide 1.2V
with a very light load:
<https://eneloop101.com/wp-content/uploads/eneloop-sanyo-white-1900-mah-cell-2007-2017-10-year-battery_-capacity-test.png>
Disabling the receiver for most of the day and only operating it for a
few minutes when propagation is good (after midnight), isn't
sufficient.  The battery voltage might be higher than 1.2V when the
receiver is off, but as soon as the receiver comes on, and the current
drain increases, the voltage will drop below 1.2V.  I forgot how much
lower.  I did some polarization testing with an Oregon Scientific Time
Machine using WWVB.  It ran on two AAA cells.  Alkaline and
carbon-zinc worked well, but NiMH lost considerable sensitivity as the
battery aged:
<https://www.learnbydestroying.com/jeffl/WWVB%20test/>
<https://www.ebay.com/itm/387144016757>

Looks antiue, has that ferrite antenna rod separate..

I actually am waering a Casio waveceptor radio watch...
That one uses a 3 V cell, just replaced that cell a while back,
should last 2 years.
 https://www.bol.com/nl/nl/p/casio-wave-ceptor-wv-58r-1aef-herenhorloge-43-mmmm-zwart/9300000047976469/
Used the ooportunity to buy some watchmaker tools, I come fro ma watchmaker family,
my uncle had a jewel and watch repair shop.

 

I just found the device.  If I get ambitious or bored, I'll put the
clock on a variable voltage power supply and see how it handles low
battery voltages.



Fun with shorting alakline batteries:
<https://www.learnbydestroying.com/jeffl/pics/Duracell/index.html>
>
I gave up on Duracell long ago, when the AA rechargebles I bought for a lot of money
did not keepd their charge even for a few days!
I still have those, repeated test once .. some result.. crap.
>
The photos are not of a common Duracell leaking electrolyte, but
rather of a premium Duracell exploding inside its metal case.  There's
a small chance that this 9V battery was a counterfeit, but it's too
late to check.
>
No generator here, but I am considering buying something like this:
https://tesup.com/uk/tesup-vertical-wind-turbines-for-homes
there is more wind than sun here :-)
>
Ummm... A tiny desktop vertical rotating turbine is not likely to
produce 10 Kw of power.  The unspecified size solar panel might
produce 10 Kw, but a small desktop device will only deliver a few
watts at best.
>
I've had some experience with vertical turbine generators.  In a
strong wind, they can't be feathered and will usually rip the base out
of the roof or whatever it's mounted on.  They also make far too much
noise.  When ground mounted, the part of the vertical turbine blades
near the ground don't contribute much power.
>
I suggest you do some reading before you waste your money:
<https://en.wikipedia.org/wiki/Vertical-axis_wind_turbine>

Nice link, I will study that and look up some of that stuff.
One idea I have is to use it on a catamaran boat with electric drive.
Testing on land would give some idea ...
Same for my flexible solar panels...




I have two LiFePO4 batteries:
<https://www.bioennopower.com/products/12v-20ah-lfp-battery>
>
That is very expensive,
I payed $872.14 for my 12 V Lifepo4 250 Ah battery pack from Aliexpress.
>
I didn't pay anywhere near full price for the two batteries.  I don't
want to explain how I obtained the batteries but I will assure you
that I didn't steal them.
>
Well, I am more lucky with a huge garden where the wind can blow,
A wind generator on the roof would produce a LOT of power here,
but might blow away in the next storm, we just had one.
But in the garden, why not?
Can you not mount something on top of an old tree?
>
Again, you can't easily feather a vertical wind turbine.  There's no
easy way to point the vertical turbine blades perpendicular to the
wind.  The only way to slow down the rotation is with some form of
brake, which essentially converts the wind energy into heat.  Imagine
your turbine dissipating 10 Kw of heat continuously.

When used to charge a battery pack, just lock it fixed when the battery is full?
Or pull a hull across it?? Dynamically if needed?
Seem no real problem to me.


I solved that problem a few years ago by convincing a neighbor to buy
a "no moving parts" weather station for about $300.
<https://tempestwx.com/station/76665/grid>
<https://shop.tempest.earth/products/tempest>
I get to play with it and he gets to deal with maintenance issues.
>
Better than mine, mine only does temperature and humidity, sends data via RF to an in-house receiver.
I also log it to a file, receive it with an RTL-SDR stick connected to a Raspberry Pi.
I have been experimenting with wind speed - and direction sensors based on temperature differences:
https://panteltje.nl/panteltje/pic/wind_pic_thermal_udp/
and by using ultrasonics:
https://panteltje.nl/pub/wind_speed_by_differential_2_ebay_distance_meters_IMG_4891.JPG
 these are 2 dolar ultrasonic distance meters from ebay..
>
That's roughly the way the Tempest weather station works.  I suggest
you look at the available data sheet, feature list, and software
before you reinvent the device.  Communications is via Wi-Fi:
<https://shop.tempest.earth/products/hub>

That link fails, with 'page does not exists'

<https://www.youtube.com/watch?v=lks6lIb5gGM>
>
See "Technical Questions" near middle of FAQ:
<https://tempest.earth/frequently-asked-questions/>
How does the ultrasonic anemometer work?
The ultra-sonic anemometer is composed of 4 transducers housed in the
top of the device. The Tempest measures wind speed and direction based
on the time of flight of ultrasonic pulses between pairs of
transducers. This allows for a high degree of accuracy especially in
variable wind conditions. An ultrasonic sensor is very good at
detecting light winds and has an advantage over mechanical sensors
which require momentum to rotate their bearings. Tempest�s ultrasonic
anemometer has an upper detection limit of 100mph (~160 kmph). Any
wind speeds above this threshold may be outside of accuracy
specifications.


Yes, sure, but it is fun to make your own for <10 dollars.
 https://www.ebay.nl/itm/185960647108
  the input is a trigger pulse,
  the output is a pulse, arriving later if more distance.
Unsolder the RX unit and put it at the other side,
then the time between trigger and pulse changes with the wind strength in that direction
 That was 1 dollar
Now use a second one TX and RX on opposite side,
trigger from the same source,
If no wind then the RX pulses arrive at the same time.
any temperature and air pressure and what not  cancels.
When wind blows you can xor the RX pulses .. or use a micro.
 that makes 2 dollars
Now do the same for north-southy if the first one was east-west
That makes 4 dollars.
And add a Microchip PIC micro for 3 dollars plus some parts...
Lots of fun to experiment
I do also have a hand held wind strength meter for on a boat.

There are many fun ultrasonic experiments, this used old ultrasonic transducers from very old TV remotes:
 https://panteltje.nl/pub/acoustic_wind_speed_phase_only_test_setup_IMG_4887.JPG
 https://panteltje.nl/pub/listening_to_ultrasonics_IMG_5145.JPG

Time of flight test in wind tunnel:
 https://panteltje.nl/pub/44kHz_radar_time_of_flight_test_in_wind_tunnel_IMG_4105.JPG

 

Well, I did some testing writing quadcopter code, these days useful for bombing I guess:
https://panteltje.nl/panteltje/quadcopter/index.html
>
Sorry, but exploding drones have been replaced by exploding pagers. 

No, drones are in, Seems Netherlands is going to help YouCrane with drones (was in the news today here)
There used to ba a guy that posted here that was working for drones for the mil.
He mysteriously stopped posting after I did that drone experiment...
I may still have some postings from him saved.



I'll pretend to be polite and not say anything about the wiring.
>
Ah, how 'bout this then?
https://panteltje.nl/pub/z80/sound_card_bottom.jpg
>
The wiring is (barely) tolerable.  However, whatever animal droppings
you used for flux is beyond disgusting.  I suggest baptizing your
wiring maze in some alcohol, which should remove the brown goo and
make your masterpiece presentable.
>
As a kid I started with 4.5 V batteries...
>
I'm still a kid. 
>
Sure, almost 80 here ...
>
I'm 76 and holding.
<http://www.learnbydestroying.com/jeffl/pics/jeffl/jeffl-wolf.gif>

Yea same hare:
 https://panteltje.nl/panteltje/live/index.html



I am still running around, biking, writing code and soldering with 60/40.
lead bad?
;-)
Inhaled resin smoke all my life,
>
I've given up running and cycling and downsized to walking and hiking.
<https://www.strava.com/athletes/103870441>


As a kid my parent had me subscribed to some walking club
Got many medals for walks I completed...

Was fun, mostly for the places we went,..
Then when I got hold of a bike I went far away...

<http://www.learnbydestroying.com/jeffl/pics/bicycles/5bikes.JPG>

WOW, I only got once, and its old, but OK for shopping (supermarket is in a nearby vllage a few miles from here).


I don't write code.  Many years ago, I had to choose between a career
in hardware or software.  I chose hardware because it was less likely
to be automated into insignificance.  So far, I think I made the right
choice. 

Well, in the seventoes I bought a Sinclair ZX80, started playing with it
then bought the book 'computer interface techniques'
 https://archive.org/details/MicroprocessorInterfacingTechniques_3rd_ed
and things took of from tehre...
 https://panteltje.nl/panteltje/z80/index.html
wrote my own CP/M clone and designed hardware
Before you knew the ZX80 had a floppy drive and all sorts of stuff:
 https://panteltje.nl/panteltje/z80/system14/diagrams/index.html
I already had met Unix when working at the local accelerator,
so when I got hold of a Linux distro in 1998 it was Linux from then on.
At work later I was designing stuff on PCI cards for in the IBM PC.. more stuff.
You canot do much without software these days, using a simple i2c chip will aready need it.
 

I still use 63/37 tin-lead solder, but have forced myself to tolerate
using ROHS dross.  I have separate soldering and desoldering stations
on my bench, one for each blend.  There's are two small fans blowing
the fumes towards the wall behind my bench, which has slowly changed
from white to brown.  I make my own rosin flux from pine tree sap and
isopropyl alcohol.  It's very organic, substitutes nicely for incense
and might even be healthy.

Neat :-)
Yes I have a small fan that I sometimes use too, but smoke gets everywhere..



BTW that Voltcraft soldering iron has adjustable preset temperatures,
so no special tips needed like a Weller.
Also I >never use a wet sponge< on the tips,
I clean tips with a piece of kleenex or even toilet paper, or rub it against the lead..
Using wet sponges kills your soldering tips, it is a sales trick.
I have tips that still look fine after 24 years.
>
I didn't know that.  I use cellulose sponges and water for tip
cleaning.  I also use some brass "wool" tip cleaners.  For the big
irons, I use a sal ammoniac (ammonium chloride) block.  When I bought
the box of Weller soldering station parts many years ago, it came with
about 50 dirty Weller tips.  I soon determined that the company that
provided me with these irons had a policy of not cleaning tips.  When
a tip became dirty with burned flux, it was replaced with a new tip.
After some experimenting, I managed to clean almost all the tips, some
of which I still use today.

Good!

Date Sujet#  Auteur
3 Oct 24 * Extech EX410A DVM Don't Buy26john larkin
4 Oct 24 +* Re: Extech EX410A DVM Don't Buy3Klaus Vestergaard Kragelund
4 Oct 24 i`* Re: Extech EX410A DVM Don't Buy2john larkin
4 Oct 24 i `- Re: Extech EX410A DVM Don't Buy1Cursitor Doom
5 Oct 24 `* Re: Extech EX410A DVM Don't Buy22Jeff Liebermann
5 Oct 24  +* Re: Extech EX410A DVM Don't Buy14Jan Panteltje
5 Oct 24  i`* Re: Extech EX410A DVM Don't Buy13Jeff Liebermann
5 Oct 24  i +* Re: Extech EX410A DVM Don't Buy8Jan Panteltje
6 Oct 24  i i`* Re: Extech EX410A DVM Don't Buy7Jeff Liebermann
6 Oct 24  i i +* Re: Extech EX410A DVM Don't Buy4Jan Panteltje
6 Oct 24  i i i+- Re: Extech EX410A DVM Don't Buy1Klaus Vestergaard Kragelund
6 Oct 24  i i i`* Re: Extech EX410A DVM Don't Buy2Jeff Liebermann
7 Oct 24  i i i `- Re: Extech EX410A DVM Don't Buy1Jan Panteltje
6 Oct 24  i i `* Re: Extech EX410A DVM Don't Buy2john larkin
6 Oct 24  i i  `- Re: Extech EX410A DVM Don't Buy1Jeff Liebermann
5 Oct 24  i `* Re: Extech EX410A DVM Don't Buy4Klaus Vestergaard Kragelund
5 Oct 24  i  +- Re: Extech EX410A DVM Don't Buy1john larkin
5 Oct 24  i  `* Re: Extech EX410A DVM Don't Buy2Jeff Liebermann
5 Oct 24  i   `- Re: Extech EX410A DVM Don't Buy1Klaus Vestergaard Kragelund
5 Oct 24  +* Re: Extech EX410A DVM Don't Buy5john larkin
5 Oct 24  i`* Re: Extech EX410A DVM Don't Buy4Jeff Liebermann
6 Oct 24  i `* Re: Extech EX410A DVM Don't Buy3Klaus Vestergaard Kragelund
18 Oct 24  i  `* Re: Extech EX410A DVM Don't Buy2john larkin
18 Oct 24  i   `- Re: Extech EX410A DVM Don't Buy1Cursitor Doom
6 Oct 24  +- Re: Extech EX410A DVM Don't Buy1legg
9 Oct 24  `- Re: Extech EX410A DVM Don't Buy1Martin Rid

Haut de la page

Les messages affichés proviennent d'usenet.

NewsPortal