.

solenoids are either push or pull type. either way there is a stopper in there that limits the travel.

also, induction heaters do have a strong magnetic field.

At work, I have a machine that is a low voltage high current machine. it simulates high amps that are needed to test a circuit breaker. it out puts up to 50,000 amps at less than 20vac. anyways. when I run it over 10,000amps, any steel in the area gets sucked in right away. and if I have any loose connections, it almost instantly turns cherry red and pops.

Michael.

Aluminium doesn't ball up because above about 700F the surface rapidly reacts with oxygen in the air forming aluminium oxide which has a much higher melting temperature than aluminium. AlO2 also has an extremely high surface tension and is less dense than the Al, so it always floats to the top.

chipdouglas said:

solenoids are either push or pull type.

Click to expand...

I googled the push type, it looks to me like they're arguably the same thing as a pull type. The coil pulls the metal into the center, and a tiny push pin pops out the other end.

Correct.

Those are very common in doorbells.