AC MOTORS

Hey Professor Mehdi, I've got a couple ideas. One person mentioned a 3 phase VFD to drive it. VFDs have gotten much cheaper. Amazon has them for around $150 (small ones). If you want to stick with a homemade driver solution, you could create what a VFD does with the PWM pins of an Arduino. You'd use 6 of them connected to the base of 6 transistors which would be holding back rectified main voltage in a DC bus. 3 are for the positive waveform and 3 for the negative waveform. And you'd have to write code that could change the default frequency of the pins to a frequency you want... And they’d have to be 120 degrees out of phase… It looks like it’s possible, but it would be a lot of coding.

Tesla would be proud.

Giffy

Would an audio amplifier help this out? You could use a signal generator and a surround sound amplifier or a multi-channel professional amplifier to output ~25v and 80w per winding (home amplifier, professional amps can do more power and/or 75v depending on design)

Hey Mehdi, Sorry about the youtube comment that was left on this video under my name. I had left my account logged in on my friend's laptop and he thought it would be a funny prank to leave that comment while it was still unlisted. I have since deleted the comment at your request.

Might be Star/Delta problem?

Could be that you just need a soft starter. Reduced voltage for low torque startup.

When I'm looking at you using tools, I cannot help to make whining noises. It's not possible you still have all fingers. You had to be born with some spare ones.

Apuis Retsam

You could transform the signal, or run it through a saturable reactor. Now that would be cool!

Adam Nash

Lucky that prop didn't take out a finger, yoru scope screen, an eye. LOL

4:09 And now let me introduce fan without vanes ...

Yo Mehdi, can u make a video about 5g wireless frequency and how to mesure that kind of frequency in the air

The skew angle of the slots in the rotor reduce vibration and smooth out torque. It's basically equivalent to an helical gear vs spur gear.

Felix

VFD are expensives, and the waveforms he wold get on his scope would make it harder to explain what is happening. The best a VFD can do is approximate a sinus and those that do are even more expensive. Also it's beside the point. If he wanted to use a VFD he would use the brushless DC motor ECU he already has.

Felix

Lol. That would be worthy of ElectroBOOM, but he's trying to demonstrate a 3 phase induction motor and the mains is 1 phase. 2 phases since it looks like he got 208 V across different outlets in his apartment. Maybe he could knock at his upstairs neighbour's door and ask if he can borrow the 3rd phase?

Felix

It's called a rotary converter, but it's basically what his motor driving another motor is. He need a bigger one. Could also do it using a 3 phase IGBT inverter, which is basically what the brushless DC motor ECU is. The rotary converter is the only thing that can produce true sinusoidal AC tho.

Felix

Is that Primitive Technology?

Felix

You Could hook it up to Mains Voltage

Hey, Mehdi, thanks for your videos! Could the screw heads be messing up the field? I would think the air gap between rotor and coils would need to be as small as possible.

I think some cellphones can measure Gauss of magnetic fields, or you can build something to measure it. There are Gauss Meter projects on the net. It would be easier for audiences to understand your shoddiness if you measured it numerically.

Mehdi, why can't you use a VFD to run it? This is what most of industry uses. I repair vfds for a living!

SimplyElectronics

Thank you!

ElectroBOOM [Mehdi Sadaghdar]

I always enjoy watching him use tools.

Just in case the need ever arises again I recommend one of these: https://www.harborfreight.com/1-8-eighth-inch-to-1-1-8-eighth-inch-tubing-cutter-92878.html

Jason Hoffman

You must of gotten my message on people calling ac motors brush-less dc motors.

Just recently became a member. First time on Patreon and well worth it.

I think , I THINK , you should try to help it out with your hands at first, kind of like old motors

Need a reverse FUULLLAAHH BRIDGE RECTIFIAHHHH. But that's probably not a thing. Free energy source? Love your videos, keep it up