Driver to drive?

[Bill Sloman]

On Monday, January 6, 2020 at 4:53:59 AM UTC+11, jla...@highlandsniptechnology.com wrote:

On Sun, 5 Jan 2020 07:35:11 -0600, John S <Sophi.2@invalid.org> wrote:

On 1/4/2020 9:00 PM, Bill Sloman wrote:
On Sunday, January 5, 2020 at 5:48:27 AM UTC+11, amdx wrote:
On 1/2/2020 8:11 PM, Bill Sloman wrote:
On Friday, January 3, 2020 at 12:05:49 PM UTC+11, John Larkin wrote:
On Thu, 2 Jan 2020 15:30:08 -0800 (PST), Klaus Kragelund
klauskvik@hotmail.com> wrote:

On Thursday, January 2, 2020 at 11:14:12 PM UTC+1, bitrex wrote:
Is powdered carbonyl iron toroid an appropriate material for winding a
small flyback transformer on? Like micrometals material #7 or 8?

I have a number of them on hand, about half an inch outside diameter.
For the inductance and ratio I need the calculator shows i'll need about
30 turns on the primary and 80 on the secondary which should easily fit
using say 26 gauge wire for the primary and 36, 38 for the secondary.
Switching frequency between 1 and 2 MHz

I have looked at the micrometals 10 years ago. AFAIR the have extreme high permeability. So they will not be good for high frequency operation, since the BH loss loop will be dominant. Utilize the high u, and go for low frequency operation

That said, I might remember all this wrong

Cheers

Klaus

Micrometals has cores down to u=1, namely not magnetic at all. But
their powdered-iron parts are lossy at high frequency and flux
density; I've burned the paint off some. KoolMu types are better.
MicroMetals may have something similar now.

At moderate power, say below 10 watts, I'd try to use a stock
dual-winding inductor as an autotransformer flyback. Winding toroids
is a nuisance.

So is designing the right inductor for the job. Finding someone to wind a bunch for you probably takes less effort, but John Larkin likes to claim that he does electronic design, so he invokes the difficulty of finding a coil winding shop as his excuse.


I don't have any problem with people having different political ideas,
but you are just going off the deep end a just being an asshole without
any provocation.

John Larkin doesn't like designing special purpose multi-winding inductors, and tries to discourage other people from doing it.

My experience is that you can get much better performing multi-winding inductors by designing them to do the job you need them to do.

The problem is that multi-winding inductors - when compared with other passive components - have a lot more variables to play with, and you chance of picking up a commercially available part that will do your job well are a whole lot poorer than they are with things like resistors and capacitors and single winding inductors.

Pushing this point may strike you as being anti-social, but my point of view is that pushing a personal prejudice that discourages people from exploiting an accessible range of design options is decidedly anti-social, to the point of being downright irresponsible.


In your opinion, of course.

I design a circuit first which may include an inductor or transformer. I
then look for an appropriate device to do the job. I can usually find
something that will work. I may adjust my circuit slightly to get best
performance with what I selected.

If I can't get the COTS magnetic device I need, then I design it. Having
no tools to wind it myself means that I must write specifications for it
then search for a facility to wind it. Then I must characterize the item
when it arrives. This takes much longer than just getting a COTS item if
I can find it.

Sometimes it makes sense to use a couple of stock transformers instead
of one custom multi-winding transformer. Clever circuit design can
usually allow using stock parts.

More parts is usually more expensive and bulkier. If you've got the space and really don't want add to a new component to your inventory, that can be an acceptable solution, but it isn't clever circuit design, just cheap.

--
Bill Sloman, Sydney

 

[John Robertson]

On 2020/01/05 3:23 p.m., edward.ming.lee@gmail.com wrote:

Folks have had success using a car battery for spot welding...Use the
starter solenoid and a push button and heavy copper lugs for the welding
points.

You can also use battery packs itself to spot weld additional one. Start with some spring mounted cells, than build it up.

I am testing my 2 Kw 18650 packs on my Leaf now. Went a little farter

Gas powered, eh?

Sorry, no gas, went further than before.

I have an ancient Aurenthtic 24VDC motorcycle that I plan to restore -
someday. Takes two deep discharge batteries and hits a top speed of
50KPH! Fast for the early 70s.

https://jetmandan.blogspot.com/2009/03/auranthetic-electric-mini-bike.html

Like I don't have enough projects!

John :-#)#

 

[Bill Sloman]

On Monday, January 6, 2020 at 4:26:50 AM UTC+11, mpm wrote:

On Tuesday, December 31, 2019 at 7:19:10 PM UTC-5, Bill Sloman wrote:

Wind turbines need to be properly engineered and maintained - they fall down if they aren't, like every other sort of civil engineering project.

Bridges fall down from time to time too, but nobody complains about renewable energy when that happens.

I'll never forget something my brother said to me when he used to live in Queens (an NYC borough): He said you just never know what's going to happen. You could be driving along the Long Island Expressway and a big pothole the size of your car could suddenly open up and that would be it for you.

I like to visit New York City, but no way I would ever want to live or work there! Too many people. (And with excessive population comes problems of sort described here: un-permitted, shady installations that pose a danger to the public!)

You don't have to go to big cities to find under-maintained bridges. There are more bridges in big cities so they are over-represented, but the underlying problem is human fallibility.
..
https://en.wikipedia.org/wiki/List_of_bridge_failures

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Monday, January 6, 2020 at 3:28:28 AM UTC+11, DecadentLinux...@decadence..org wrote:

Bill Sloman <bill.sloman@ieee.org> wrote in
news:254c6d62-9a43-42d1-984e-103c720ea19b@googlegroups.com:

And you are silly enough to make that claim without having any
kind of information to base it on.

How does that feel, hypocritical fucktard?

ISTR you claiming to have great knowledge about gapping pot cores,
when in fact the exact opposite is true.

You made the silly claim that gapping a pot core was useful as a device to minimise ringing in a switching inverter, when the main effect of gapping the core is to change the inductance the windings in the transformer, which can change what the ringing looks like, but doesn't address the source of the ringing.

This is actually entirely obvious, and can be worked out from elementary theory. I've used gapped pot cores (not all that often), and went to trouble of understanding what I was doing.

You don't seem to have bothered, but think that having been exposed to a lot of gapped cores automatically instilled some kind of comprehension into your brain, which obviously didn't happen.

--
Bill Sloman, Sydney

 

[Michael Terrell]

On Sunday, January 5, 2020 at 5:13:54 PM UTC-5, Rick C wrote:

In all the references I've looked at I haven't seen anyone state that as a show stopper until it is solved. What do you know about it? Hydrogen is not as small as helium.

That's interesting.

A Hydrogen atom is one Proton and one Electron.

A Helium atop is two Protons, two Electrons and one or two Neutrons

You need to learn about 'hydrogen embrittlement in steel'.

 

On Sunday, January 5, 2020 at 2:54:58 PM UTC-10, Michael Terrell wrote:

On Sunday, January 5, 2020 at 5:13:54 PM UTC-5, Rick C wrote:

In all the references I've looked at I haven't seen anyone state that as a show stopper until it is solved. What do you know about it? Hydrogen is not as small as helium.


That's interesting.

A Hydrogen atom is one Proton and one Electron.

A Helium atop is two Protons, two Electrons and one or two Neutrons

You need to learn about 'hydrogen embrittlement in steel'.

Helium is a gas of atoms .
Hydrogen is a gas of H2 molecules.
He atoms are used in leak detectors for that reason.
He is smaller than H2.

 

[Whoey Louie]

On Sunday, January 5, 2020 at 5:11:36 PM UTC-5, John Doe wrote:

I am neat, careful, and quick to avoid overheating when soldering. How
possible is it to solder a large lithium-ion battery without damaging or
degrading the battery? For connecting batteries together.

I like doing things right, so I'm willing to buy a $100 Chinese battery
connector welding box. But the foreseeable need is only about five two-
cell battery packs. You do the math...

Thanks.




--

Gotta love water-soluble resin solder. Sparkling clean after a warm
water rinse. That's my plug.

Aren't similar batteries that have tabs on them available? You can then solder to the tabs, which is easy.

 

[Winfield Hill]

Sorry for top-posting. Will be mailing out free
sets of two RIS-796 digital 250A pulser PCBs, on
Monday, send me your address. Full use info below.
Have fun, get ready for new RIS-796A analog version.
Inexpensive parts, you too can make massive pulses.

Winfield Hill wrote...

Updated files on DropBox. Writeups for the
RIS-796 digital, with scope traces, and the
new RIS-796A analog. Now ready to order PCB:

https://www.dropbox.com/sh/tcmiahzzughadfk/AABtgFDy01cuTDWDRjujP6jva?dl=1

Winfield Hill wrote...
Winfield Hill wrote...

First, referencing a previous s.e.d. thread:
Title: Trying JLCPCB for 200A 6kW LED pulser.
Was about my RIS-796 design, implementing a
refined version of the 200-amp theatre LED
pulser in AoE x-Chapters, read 3x.19 And
about procuring PCBs (arriving in a few days).
Free blank PCBs available, w/ free shipping.

See RIS-796_2_proto_fab-2, in Dropbox folder:

https://www.dropbox.com/sh/tcmiahzzughadfk/AABtgFDy01cuTDWDRjujP6jva?dl=1

New project: Make a similar 200A LED pulser,
but with active analog op-amp control, rather
then a gate pulse (as in 3x.19 and RIS-796).
New project, RIS-496A (the A is for analog),
see x-Chapters 4x.26 for concept and theory.

Complete schematic of the new design, see
file RIS-796A_1_sch_bw.pdf For details of
the output stage, first read or scan 4x.26.
Doing the calculations with R1 = 20mR, find
that gate resistor R2 must be low, 3.3 ohms,
implying the use of a serious driver, BUF634.
Keep in mind, driving MOSFET's Ciss = 7600pF.
Taking advantage of precision analog waveform
control, and seeking to combat LED failure, a
rise-fall linear ramp has been added, D3 D4.
Most other accouterments may be obvious.

Expected result, exceed performance of the
original "digital" drive, by adding waveform
refinements. At the expense of more parts.

Inviting discussion here, in case some ideas
come up, before I finish the new PCB layout.

A new file added to the DropBox folder:
RIS-796A_4x.26_calculations, showing simple
R3 and R2 C2 math for the 200A circuit.

In 4x.26, we showed measurements for a 2.5 amp
25ns programmable current-source at half scale,
but now we seek to explore up to 250 amps.

Free "digital" PCBs are available now, and the
"analog" PCBs will be available after layout.

--
Thanks,
- Win

 

[Michael Terrell]

On Sunday, January 5, 2020 at 8:07:07 PM UTC-5, omni...@gmail.com wrote:

On Sunday, January 5, 2020 at 2:54:58 PM UTC-10, Michael Terrell wrote:
On Sunday, January 5, 2020 at 5:13:54 PM UTC-5, Rick C wrote:

In all the references I've looked at I haven't seen anyone state that as a show stopper until it is solved. What do you know about it? Hydrogen is not as small as helium.


That's interesting.

A Hydrogen atom is one Proton and one Electron.

A Helium atop is two Protons, two Electrons and one or two Neutrons

You need to learn about 'hydrogen embrittlement in steel'.

Helium is a gas of atoms .
Hydrogen is a gas of H2 molecules.
He atoms are used in leak detectors for that reason.
He is smaller than H2.

Yet you ignored the problem of 'hydrogen embrittlement in steel'.

 

On Sunday, January 5, 2020 at 2:12:33 PM UTC-5, edward...@gmail.com wrote:

On Sunday, January 5, 2020 at 11:08:50 AM UTC-8, Rick C wrote:
On Sunday, January 5, 2020 at 1:38:49 PM UTC-5, keith wright wrote:
On Sunday, 5 January 2020 10:13:50 UTC-8, jla...@highlandsniptechnology.com wrote:
.. can always charge the battery downhill.

Don't hybrids have regenerative braking?

All hybrids have regenerative braking, usually up to about 30kW or so..

Yes, but the battery is very small, and peaking out very often.


The hills in SF are not long enough to peak out the battery on most hybrids.

The hills here are short and choppy, just a few blocks long, yet
hybrids don't do well. Maybe they have to use the real friction brakes
a lot.
..

It depends what you mean by "don't do well" - I expect they still do much, much better than conventional vehicles. If the hills are too steep the 30kW regeneration limit is reached and the friction brakes are used, in which case it does waste energy, but a significant fraction is still recovered for going up the next hill.

My Prius usually consumes only about 50-600% of the fuel of my Mazda 3 (comparable vehicles in size, weight and performance) regardless of the terrain. Yes, the absolute numbers will vary for both but the Prius is always better, especially in slow city traffic such as in SF.

30 kW is about 40 Hp. I would expect a hybrid to have more power in the engine and battery, but I guess they don't charge at near the same rate as discharge. My car regens at up to 100 kW I believe. I guess that's an advantage of a larger battery. I barely use the brake.

and larger motor. It's too expensive to put in a big electric motor together with a gas motor. That's why GM is dropping the volt.

Hmmm, I dont believe that. The Prius effectively does the same thing and they have been around (and will continue to be around) for a while.

I haven't looked but I'd assume there are studies done about system efficiencies wrt to hybrid vehicles/EV and moving the problem from the multitude of gasoline vehicles to generating stations.
In addition, many ppl throw out numbers for efficiencies of this electric motor when motoring, or energy when doing regenerative braking, etc. but quite frankly, all those numbers are useless individually - it is a SYSTEMS issue and I'd like to think that at some point a number of math models were done of various hybrid and EV configurations to a) evaluate component efficiencies takeoffs and b) identify and design to real-world operational scenarios/operational envelopes, and not just throw electric motors and internal combustion engines on a chassis and see who will buy it under the moniker of 'environment friendly'...

As a side note, I am in the market for a new vehicle...I looked at a Toyota highlander hybrid. The base adder for a hybrid is about 1800 USD above the gasoline version. I tend to keep my vehicles past 100K miles. By most accounts, the design lifetime of the battery packs are 100K miles, and the current replacement cost is $4800 USD. Hmmmm do the back of the envelope math, and the gasoline fuel usage costs over the 100K lifetime compared to the hybrid version has a much narrower gap that one would think. The cost of 'fuel' has been moved/redistributed. One could avoid the end of lifetime cost of a new battery by getting rid of the vehicle before having to buy a new battery pack - maybe that is what the manufactures are betting on.
j

 

[Rick C]

On Sunday, January 5, 2020 at 7:54:58 PM UTC-5, Michael Terrell wrote:

On Sunday, January 5, 2020 at 5:13:54 PM UTC-5, Rick C wrote:

In all the references I've looked at I haven't seen anyone state that as a show stopper until it is solved. What do you know about it? Hydrogen is not as small as helium.


That's interesting.

A Hydrogen atom is one Proton and one Electron.

A Helium atop is two Protons, two Electrons and one or two Neutrons

You need to learn about 'hydrogen embrittlement in steel'.

Hydrogen seldom exists as a single atom. That would be a free radical. Hydrogen exists as H2. We call that a molecule. Can you say mol¡e¡cule?

Then there is the fact that the two protons in a Helium atom hold the electrons much closer than the single electron in the Hydrogen atom. So even a single atom of Hydrogen is half again larger than a Helium atom which has a full valence shell so doesn't form diatomic molecules. He has a diameter of about 1 Å and the H2 molecule is 2.11 Å along the long axis.

You need to learn about physics and chemistry.

--

Rick C.

+++- Get 1,000 miles of free Supercharging
+++- Tesla referral code - https://ts.la/richard11209

 

[John Doe]

Whoey Louie <trader4@optonline.net> wrote:

John Doe wrote:

I am neat, careful, and quick to avoid overheating when
soldering. How possible is it to solder a large lithium-ion
battery without damaging or degrading the battery? For connecting
batteries together.

I like doing things right, so I'm willing to buy a $100 Chinese
battery connector welding box. But the foreseeable need is only
about five two- cell battery packs. You do the math...

Gotta love water-soluble resin solder. Sparkling clean after a
warm water rinse. That's my plug.

Aren't similar batteries that have tabs on them available? You can
then solder to the tabs, which is easy.

Probably, if I didn't already have plenty. I was planning to charge
them in an ordinary slotted charger, using a battery holder on the
project.

That is a good point. If you are planning to use them in a pack with
a balance charger, can find the correct source batteries in a
cordless tool battery pack, if they are not much more expensive than
bare batteries, and if they are properly connected (deduced by the
voltage and capacity), that will save some work. The welds on those
batteries are great.

 

[Rick C]

On Sunday, January 5, 2020 at 8:59:27 PM UTC-5, jjhu...@gmail.com wrote:

On Sunday, January 5, 2020 at 2:12:33 PM UTC-5, edward...@gmail.com wrote:

and larger motor. It's too expensive to put in a big electric motor together with a gas motor. That's why GM is dropping the volt.

Hmmm, I dont believe that. The Prius effectively does the same thing and they have been around (and will continue to be around) for a while.

Edward seems to have an agenda with regards to EVs. The Prius has combined 121 HP, a 1.8 liter gas engine and electric engine. So while it won't win any stop light derbies it's a whole lot more than 30 kW.


> I haven't looked but I'd assume there are studies done about system efficiencies wrt to hybrid vehicles/EV and moving the problem from the multitude of gasoline vehicles to generating stations.

I'm not sure what you are saying. Are you talking about charging issues?


> In addition, many ppl throw out numbers for efficiencies of this electric motor when motoring, or energy when doing regenerative braking, etc. but quite frankly, all those numbers are useless individually - it is a SYSTEMS issue and I'd like to think that at some point a number of math models were done of various hybrid and EV configurations to a) evaluate component efficiencies takeoffs and b) identify and design to real-world operational scenarios/operational envelopes, and not just throw electric motors and internal combustion engines on a chassis and see who will buy it under the moniker of 'environment friendly'...

It depends on what you are talking about as to what system needs to be considered.


> As a side note, I am in the market for a new vehicle...I looked at a Toyota highlander hybrid. The base adder for a hybrid is about 1800 USD above the gasoline version. I tend to keep my vehicles past 100K miles. By most accounts, the design lifetime of the battery packs are 100K miles, and the current replacement cost is $4800 USD. Hmmmm do the back of the envelope math, and the gasoline fuel usage costs over the 100K lifetime compared to the hybrid version has a much narrower gap that one would think. The cost of 'fuel' has been moved/redistributed. One could avoid the end of lifetime cost of a new battery by getting rid of the vehicle before having to buy a new battery pack - maybe that is what the manufactures are betting on.

Not sure why you think you will need a new battery at 100,000 miles. They are warrantied for that, no? So do you really think it's going to go at 101,000 miles? If your car warranty is for 50,000 miles are your doors expected to fall off at 51,000 miles?

--

Rick C.

++++ Get 1,000 miles of free Supercharging
++++ Tesla referral code - https://ts.la/richard11209

 

[Bill Sloman]

On Monday, January 6, 2020 at 4:57:11 AM UTC+11, Rick C wrote:

On Sunday, January 5, 2020 at 8:59:37 AM UTC-5, Rob wrote:
jlarkin@highlandsniptechnology.com <jlarkin@highlandsniptechnology.com> wrote:
On 03 Jan 2020 15:23:30 GMT, Rob <nomail@example.com> wrote:

John Larkin <jlarkin@highland_atwork_technology.com> wrote:
On 02 Jan 2020 22:08:21 GMT, Rob <nomail@example.com> wrote:

John Larkin <jlarkin@highland_atwork_technology.com> wrote:
The electric busses here do climb the hills better that diesels, and
need less maintenance, but they get their power from overhead
trolleys, not tons of batteries. Lots more ugly wires.

We used to have those in the previous century in some cities, but
nowadays the busses have batteries and the overhead trolleys are
only present in the bus station, where they charge the batteries
during the resting stop between trips.

What is the ratio between charging and running? Our busses don't stop
very long.

It depends on the schedule and the amount of traffic. Of course when
there is heavy traffic and the bus arrives late, the stop tends to be
shorter as it preferably would depart on-time again.

This charging does not occur at every stop, only at the endpoints of
each line and/or in the central bus station in a city (near the train
station).

We still run cable cars, where the entire line runs off one big
electric motor in the central barn. They are a hoot to ride,
especially the Hyde Street line at night.

I have been in SF in 1989 and have seen the cable cars and their
power station. Incredible that this works...

Of course here the country is mostly flat and buses likely spend a
bit less energy (driving down a hill rarely recoups all the energy
that was required to climb it, although electric vehicles are better
at that than other types).

Some of the older diesel busses had to ask the passengers to get off
at the bottom of a hill, and walk up to meet the bus again.

Hybrids cars don't get very good mileage here. Well, gas cars don't
either.

But electric cars, on the other hand, should get good mileage!
Of course only when you operate them in the middle of the battery
charge, so you can always charge the battery downhill.

Huh? Unless you charge to 100% at the top of a hill you can always regen.. The speed is slower so less braking very near 100%. Anything below 90% gives full regen in my car. What you call the "middle of the battery charge" is 10% to 90%, the range you would normally operate the battery anyway.


Diesel busses are gone here. We only have LPG, CNG and Hydrogen
busses (in addition to the electric ones). LPG is the direct replacement
for Diesel in volume, the others are upcoming techniques that often
are operating as experiments on a single line due to the infrastucture
neccissity.

Seems we can make hydrogen through electrolysis with 80% efficiency.
That's not really bad.

It wouldn't be if the electrolysis stage was the only one where you lost energy.

The round trip from electric power via hydrogen gas back to electric power gets you back about 25% of the energy you started out with.

There are a bunch of "industry experts" who want Australia to install huge solar farms to make hydrogen to get liquified and shipped off to Korea and Japan.

They figure that they can make money on the deal, and may well be right.

A long undersea high voltage cable would probably be a better way of moving the power the 5000 miles involved, but the up-front cost would be higher.

> If we have excess electrical generation capacity it can be used to make hydrogen which can be injected into the natural gas distribution system replacing carbon releasing gas.

Batteries give you back about 85% of the energy you put in. It's a much better deal, but you'd need a lot of batteries, and Elon Musk seems to be the only guy who has spent big on mass-producing them. And his output is aimed at electric cars, rather than grid back-up for which vanadium redox cells seem to be a better choice.

> They are looking at doing this in the UK since they seem to have a higher proportion of gas heat in the homes and like it, they like it a lot!

For space heating the thermodynamics may be a bit better - until you compare burning gas with driving an electrically power heat-pump. Heat pumps do represent a bigger capital investment than a gas burner, but if you do the end to end sums they do come out ahead.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Monday, January 6, 2020 at 9:13:54 AM UTC+11, Rick C wrote:

On Sunday, January 5, 2020 at 3:38:04 PM UTC-5, keith wright wrote:
On Sunday, 5 January 2020 11:19:33 UTC-8, Rick C wrote:
...

Unfortunately the round-trip efficiency is more likely to be in the 30-40% region. The losses are a combination of theoretical limitations (~83% each way) and practical ones.

Not sure what you mean by "round trip". Are you talking about the fuel cell efficiency in a car? I have no idea what you mean about 83% "each way".

By round trip, I mean from electrical energy to hydrogen and back. They both suffer from theoretical losses since part of the energy is unavoidably converted to heat during electrolysis.

The reverse process is not hydrolysis... ??? The reverse would be a fuel cell. I don't know much about them but there they don't have the "theoretical" limitations that hydrolysis does.

Besides. you are talking about electricity storage. I was talking about using the H2 for heating. This makes good sense anywhere there is gas pipelines. They are very common in the UK it seems having been promoted some time back to use the plentiful gas from the North Sea.


In the UK they want to use the H2 for heat which is pretty often 100% efficient. I don't know of other uses for natural gas/H2 in this country than heating the home, water, cooking... all of which are pretty efficient.


It can still be viable for long-term energy storage as the cost of hydrogen storage facilities can be orders of magnitude lower than batteries..

https://www.nrel.gov/docs/fy19osti/73520.pdf

Oh, I see from the link you are talking about grid storage by hydrolysis to H2. No, I don't think that would be a good idea. I was talking about H2 generation from excess electrical capacity such as solar or wind and storage for use as gas, not to back up electrical use. By using excess capacity the price of the energy source is minimal.

...

OK - even then using the hydrogen for generating electricity is probably one of the better applications.

Not sure why that would be. It has all the same efficiency issues as natural gas. I guess it is another way to provide peaking generation.


Mixing hydrogen with natural gas has been proposed although it looks like a significant issue is leakage through piping walls due to the small size of the hydrogen molecule.

In all the references I've looked at I haven't seen anyone state that as a show stopper until it is solved. What do you know about it? Hydrogen is not as small as helium.

It's small enough that hydrogen leakage by diffusion is a significant problem, compounded by the fact that mixtures of hydrogen and air are explosive over a wide range of proportions - air containing more than 4% hydrogen can ignite and is easy to ignite.

Since town gas contained quite a lot of hydrogen this isn't an unfamiliar problem, and the precautions required are well known (if not always applied as carefully as they might be).

https://en.wikipedia.org/wiki/Hydrogen_safety

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Monday, January 6, 2020 at 11:54:58 AM UTC+11, Michael Terrell wrote:

On Sunday, January 5, 2020 at 5:13:54 PM UTC-5, Rick C wrote:

In all the references I've looked at I haven't seen anyone state that as a show stopper until it is solved. What do you know about it? Hydrogen is not as small as helium.

That's interesting.

A Hydrogen atom is one Proton and one Electron.

But hydrogen gas is diatomic - H2 - while helium gas is monatomic- He.

> A Helium atop is two Protons, two Electrons and one or two Neutrons

Mostly two. He-3 is stable but the natural abundance is 1.3 ppm.

The university of NSW has a quantum comnputer that has to be cooled with He-3 to work, and their He-3 comes from the US where it's collected from nuclear reactors, which spit out quite a lot of alpha-particle (He-3)

> You need to learn about 'hydrogen embrittlement in steel'.

That too. But town gas contained quite a lot of hydrogen so the problem has been dealt with in the past.

--
Bill Sloman, Sydney

 

[Jasen Betts]

On 2020-01-05, John Doe <always.look@message.header> wrote:

I am neat, careful, and quick to avoid overheating when soldering. How
possible is it to solder a large lithium-ion battery without damaging or
degrading the battery? For connecting batteries together.

I like doing things right, so I'm willing to buy a $100 Chinese battery
connector welding box. But the foreseeable need is only about five two-
cell battery packs. You do the math...

can you rent, or borrow one, or contract out the spot welding?
or perhaps build one from a MOT.

--
Jasen.

 

[Jasen Betts]

On 2020-01-05, Rick C <gnuarm.deletethisbit@gmail.com> wrote:

On Sunday, January 5, 2020 at 8:52:16 AM UTC-5, Martin Brown wrote:

Most people used the 80188/6 for embedded PC.

What exactly is an "embedded PC"? PC stands for Personal Computer
which is not an embedded computer at all. What are you trying to say?

PC compatible embedded in some other device (eg kiosk, ATM, video
slot machine, etc.)

PC/104 possibly also qualifies as embedded pc.

--
Jasen.

 

[whit3rd]

On Sunday, January 5, 2020 at 2:13:54 PM UTC-8, Rick C wrote:

On Sunday, January 5, 2020 at 3:38:04 PM UTC-5, keith wright wrote:

Mixing hydrogen with natural gas has been proposed although it looks like a significant issue is leakage through piping walls due to the small size of the hydrogen molecule.

In all the references I've looked at I haven't seen anyone state that as a show stopper until it is solved. >What do you know about it? Hydrogen is not as small as helium.

In theory, a Hydrogen molecule has the same electron structure (two electrons in 1S shell) as Helium,
thus the van der Waals volume of hydrogen, 0.02651 L/mol, is comparable to that of
Helium, 0.0238 L/mol. It's about the same size.

The thing is, H2 doesn't diffuse through most metals; if you get it trapped by
welding, or neutrons diffusing in, and turning to protons (hydrogen nuclei), that's a problem.
A monatomic hydrogen atom in a metal matrix IS a weakening impurity.
A pipe or tank doesn't leak too badly with gas pressure, though.

 

[Rick C]

On Sunday, January 5, 2020 at 11:54:41 PM UTC-5, whit3rd wrote:

On Sunday, January 5, 2020 at 2:13:54 PM UTC-8, Rick C wrote:
On Sunday, January 5, 2020 at 3:38:04 PM UTC-5, keith wright wrote:

Mixing hydrogen with natural gas has been proposed although it looks like a significant issue is leakage through piping walls due to the small size of the hydrogen molecule.

In all the references I've looked at I haven't seen anyone state that as a show stopper until it is solved. >What do you know about it? Hydrogen is not as small as helium.

In theory, a Hydrogen molecule has the same electron structure (two electrons in 1S shell) as Helium,

Not really. He is a single atom so 2 electrons in a single 1S shell. H2 is two atoms sharing 2 electrons between them. Not really the same.

thus the van der Waals volume of hydrogen, 0.02651 L/mol, is comparable to that of
Helium, 0.0238 L/mol. It's about the same size.

The thing is, H2 doesn't diffuse through most metals; if you get it trapped by
welding, or neutrons diffusing in, and turning to protons (hydrogen nuclei), that's a problem.
A monatomic hydrogen atom in a metal matrix IS a weakening impurity.
A pipe or tank doesn't leak too badly with gas pressure, though.

Exactly. They mix H2 with methane in public gas distribution, so it can't be too bad.

--

Rick C.

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