14
votes
Is there any material that blocks a static magnetic field?
Yes, there are several different ways to manipulate magnetic fields. One way to shield an area from a magnetic field is to place a highly ferrous material like iron next to the source of the magnetic ...
- 593
5
votes
Accepted
How is it possible electromagnets keep a heavy maglev train levitating without forcing anything metallic to be flinged away?
First off there are many different types of maglev prototypes out there each with their pros and cons. In fact some designs have the drawback of needing shielded compartments for people with ...
- 593
3
votes
Accepted
Can you use an electromagnet to break the connection of a permanent magnet?
These are called electropermanent magnets.
Source: https://en.wikipedia.org/wiki/Electropermanent_magnet
The control can either come from rotating one of the magnets, or by using a control coil. If ...
- 205
3
votes
Generating practical power without an iron core, but with high RPM
the iron structure(s) inside a generator serve the purpose of minimizing flux leakage, which maximizes the utilization of the magnetic field in generating electricity. One of the ways in which they ...
- 15.3k
3
votes
Accepted
Defining camera as a passive radar
Not really.
Firstly the RA in RADAR stands for RAdio which covers significantly longer wavelengths than the visible light (an in some cases near infra-red) which cameras can detect.
While light ...
- 15.3k
3
votes
Accepted
Protect equipment against electromagnetic radiation
There are 2 effects to look out for:
Magnetic induction into wiring from e.g. coronal mass ejections. The electrical grid is already largely protected against these events. To protect equipment in ...
- 746
3
votes
Accepted
What are possible applications for room temperature superconductor requiring extreme presssure?
Such applications would be extremely rare. Cooling with liquid nitrogen is easy and cheap, so using regular high temperature superconductors would almost always be preferred.
The paper claiming +15C ...
- 469
3
votes
Accepted
Controlled oscillation of a piano string by electromagnetic, mechanical, or other means
What you describe has been on the market for over 40 years for electric guitar use; it is called an E-Bow. It contains a sense coil, a drive coil, a battery, and an amplifier circuit inside a case you ...
- 15.3k
2
votes
Accepted
Some questions about liquid nitrogen cooling
Regarding questions 2 and 3, I think you need to look deeper in the chemistry, reactivity, and heat transfer characteristics of Nitrogen.
1) It is not a noble gas. It is reactive, and you benefit ...
- 196
2
votes
Accepted
Quantifying Static Electricity Hazard with High Explosives
Static electricity is a major issue when handling or dealing with explosives.
When blast holes are loaded with ANFO (ammonium nitrate fuel oil) as the main explosive, and a specific density of ANFO ...
- 9,752
2
votes
Can a wireless signal of sufficiently high energy damage a wireless transceiver?
Yes, but it's unlikely. Damage from other frequencies will be limited because typical receivers have a pre-select filter after the antenna to filter out other frequencies. In band signals pass through ...
2
votes
Accepted
How to split mercury with a magnetic force?
It looks like it should work. It is a little more geometry specific than you are thinking, so I have modified your design below.
It will require a reasonable amount of experimentation to perfect the ...
- 8,285
2
votes
Magnetic treatment of hard water to prevent scale and corrosion? How does this work?
It's snake oil. From a physics standpoint, aqueous chemical reaction dynamics do not couple to magnetic fields.
- 15.3k
2
votes
Can a Foucault's current brake be used on the rails themselves to brake trains?
Yes they can and they are in use. Details on Wiki
By Sebastian Terfloth User:Sese_Ingolstadt - Own work, CC BY-SA 3.0
A linear eddy current brake in a German ICE 3 high-speed train in action.
2
votes
Magnetic treatment of hard water to prevent scale and corrosion? How does this work?
There's very little data available to evaluate these claims. The manufacturers tend to rely on anecdotal information and testimonials rather than hard data, and no-one else really has any incentive ...
- 1,031
2
votes
Building oscillating magnetic field circuit
To make sure the inductor will respond that fast, you need to solve for the size of the inductor (which will make your magnetic field) which will be resonant at 1000Hz when coupled with a capacitor of ...
- 15.3k
2
votes
What Goes Into Making a Variable Field Magnetic Motor?
Variable Field magnetic Motor can mean different things depending on the context. What I saw in the video is completely different to what I thought when I read the title of the question.
The first ...
- 24.3k
2
votes
Use magnetic levitation to lift a carousel capable of turning 9000lbs
This isn't a real answer, but I feel compelled to provide it. What you are suggesting is perhaps possible, but very, very complicated. You will need to hire experts to engineer a magnetic bearing of ...
- 915
2
votes
Accepted
Linear solenoid mount
Figure 1. An image search for "M3 clevis male" throws up a wheelbarrow-full of images.
You could use a female thread version but would need to connect the them with a male stud and maybe ...
- 11.1k
2
votes
Accepted
Does an iPhone on airplane mode continue to emit electromagnetic radiation field?
All electric and electronic devices emit EM waves as a matter of course because changing current flows will produce waves like a motor, clock, or pocket calculator. But then there are also devices ...
- 5,629
2
votes
Recent breakthrough on Inertial Confinement Nuclear Fusion at NIF
Assuming this part of your post was correct, "...it has been demonstrated that it is now possible to make Nuclear Fusion generate more energy than is required for its equipment to operate", ...
- 726
2
votes
Recent breakthrough on Inertial Confinement Nuclear Fusion at NIF
Proposals for Magneto-inertial fusion do exist and research is ongoing. Lasers are good at heating and magnetic fields are good at confinement, so combining them may make it possible to pass the ...
- 469
2
votes
Accepted
What are the benefits of using a spring as a drive screw in this electronic deadbolt?
The reason drive screws are used is because they give mechanical advantage.
Solenoids are linear devices and don't have inherent use leverage for mechanical advantage. A rotary motor with a small ...
- 5,629
1
vote
What is the material requirement for Van der Graff generator sphere?
You want to deposit charge inside the high voltage terminal.
You'll need some mechanical strength for that and because the charge is deposited near the middle you'll need an conducting path to the ...
- 391
1
vote
Is there a motor design where a rotor gradually moves into a stator?
It’s a pointless design since all you do is decrease the amount of magnetic coupling between the rotor and stator. You may as well just reduce the current - it’ll have the same effect.
You’d have to ...
1
vote
Magnetic treatment of hard water to prevent scale and corrosion? How does this work?
Your quote is an explanation of how scale works, not of how the 'magnetic' system works.
There is a suggestion that 'magnetic' systems cause the calcite to precipitate out as sand rather than as scale ...
- 824
Only top scored, non community-wiki answers of a minimum length are eligible