Here's something that might have relevance to this discussion .
Back in the early 70's at tech college we were working on electrical motor systems - mainly three phase AC motors .
However we did a bit of playing with an old DC series wound motor. The instructor told us the usual bumph - including the fact that DC motors are better and other forgettable stuff.
However he did tell us not to mess around too much with it and to never run under load free conditions .The motor would just accelerate uncontrollably .So myself and another apprentice decided to do that, red flag to bull springs to mind .
Disconnected the motor from the machinery attached to it but before we could try it out the instructor caught and said some swear words and asked us what we were playing at. "Trying to build a time machine sir - thought if we reached the speed light ,you know HG Wells anall that"
Turns out that motor would accelerate until self destruction since the heat generated would destroy the bearings and the housings. Forgot all
about that incident but having read through this thread a bit a light bulb went off in my head.
"So where would the energy come from? I now ask myself"
This fellow here says never run this type of motor because there is no bearing at the load end , is that a convenient way to hide the constant acceleration thing?
View: https://www.youtube.com/watch?v=EAxWAtvrVto
I could be wrong but removing the drive end bearing maybe just a convenient way of hushing up that phenomenon. He doesn't mention the fact that DC motor must only be run under load.
Alternating current flows in one direction and reverses 180 degrees 50 times a second, if we are still on 50Hz . Back and forth. So a motor accelerates in one direction and a fraction of a second later it current should provide a force of rotation in the opposite direction. How did this system ever catch on . The motor must receive it's impetus from the initial burst of current. The constant switch in direction back and forth must limit the power of the motor - wasting electrical power and pouring money into the electric company coffers.
Direct current provides a rotational force in one one direction and the amount of current would be limited by the load attached to the rotor. Must be far more efficient.
Correct me if I'm wrong - was involved in industrial electrical engineering most of my working life . Never thought to question the damn thing.
I will watch the Pete and Pete vid when I get the chance . I will have a chuckle if I've wasted all those years.
I know we used to
Back in the early 70's at tech college we were working on electrical motor systems - mainly three phase AC motors .
However we did a bit of playing with an old DC series wound motor. The instructor told us the usual bumph - including the fact that DC motors are better and other forgettable stuff.
However he did tell us not to mess around too much with it and to never run under load free conditions .The motor would just accelerate uncontrollably .So myself and another apprentice decided to do that, red flag to bull springs to mind .
Disconnected the motor from the machinery attached to it but before we could try it out the instructor caught and said some swear words and asked us what we were playing at. "Trying to build a time machine sir - thought if we reached the speed light ,you know HG Wells anall that"
Turns out that motor would accelerate until self destruction since the heat generated would destroy the bearings and the housings. Forgot all
about that incident but having read through this thread a bit a light bulb went off in my head.
"So where would the energy come from? I now ask myself"
This fellow here says never run this type of motor because there is no bearing at the load end , is that a convenient way to hide the constant acceleration thing?
View: https://www.youtube.com/watch?v=EAxWAtvrVto
I could be wrong but removing the drive end bearing maybe just a convenient way of hushing up that phenomenon. He doesn't mention the fact that DC motor must only be run under load.
Alternating current flows in one direction and reverses 180 degrees 50 times a second, if we are still on 50Hz . Back and forth. So a motor accelerates in one direction and a fraction of a second later it current should provide a force of rotation in the opposite direction. How did this system ever catch on . The motor must receive it's impetus from the initial burst of current. The constant switch in direction back and forth must limit the power of the motor - wasting electrical power and pouring money into the electric company coffers.
Direct current provides a rotational force in one one direction and the amount of current would be limited by the load attached to the rotor. Must be far more efficient.
Correct me if I'm wrong - was involved in industrial electrical engineering most of my working life . Never thought to question the damn thing.
I will watch the Pete and Pete vid when I get the chance . I will have a chuckle if I've wasted all those years.
I know we used to

