In America such calculations are normally done with decade boxes and variable voltage power supplies.

There are simply no end of circuits already solved -- sitting on the shelf for this and that purpose.

You need to hit the books -- at a library dedicated to electrical engineering.

You'll also find amazing amounts of knowledge in basic electrical engineering texts.

As for the principle I think you'll agreed it's obvious: a steady DC induced magnetic field in the MAIN WINDINGS will cause the rotor - -with its induced magnetism to brake to a stop.

One need only figure out how to break the AC connection ( a switch ? ) while making a DC connection. ( the same switch ? )

A decade box ( of resistors ) tapping a DC power supply ( half-wave ) ) would start out at high values and low current -- later being adjusted down to a value that stops rotation without collateral damage...

This test rig would then be followed by a production solution with tweaks for switches and time delay before drop out.


However, it does seem over engineered since a simple pause in power would seem to bring a washing machine to an acceptable halt without further complication -- and it's expense.


More generally, we are electricians who install field wiring/ wire buildings.

As a rule, we don't have bench equipment and are entirely unconcerned about solving engineering problems -- particularly ones that constitute the typical college course.

I'm sure that you'll find other forums much more dedicated to such topics.

They're out there.

It really is a different mind-set.

We tend to be focused on what's going to make our customers and inspectors happy.

We're not allowed to self-engineer -- when it's going into a building.

That's the motivation for the NEC. Only tested and proven devices are deemed worthy - -and only when they've been installed according to manufacturer's instructions.

That turns out to be a lot tougher than one might think. Just that alone can take 10,000 hours of field experience on top of 1,000s of hours of book learning.