The bistander thread

[Netica]

Hi Netica,

I'll reply here because I try hard to avoid threads started by a certain member. Analog panel meters are typically a moving coil type or other movement involving a coil. They have a very low resistance and essentially appear as a short circuit element in a circuit, so have a very low voltage drop across the meter terminals, even if there is a high voltage source for the circuit. Even though the meter has a very low potential difference across its terminals, it can still have a very high potential difference (voltage with respect to) other circuit nodes. For that reason it is usually wired adjacent to the most negative point (node, or negative of the power supply) of the circuit, which is typical ground, if you use a ground.

If it is a digital panel meter, it would use a csr (current sensing resistor) and a power supply for the led/lcd display. Such a device could galvanticly connect high voltage to the display circuit. I'd certainly check the specifications before using a digital meter in a high voltage circuit.

A fuse is a good idea. If you're unfamiliar or uncertain, you're welcome to post your schematic here and I'll comment.

Be careful out there,
bi

Hi bistander,

Thanks for your advise.
I am only using a panel meter.
So from what you are saying I take it that you can run it like normal but best to be on the negative side.
My thoughts are that even though it is high voltage it shouldn't matter as it is all the same potential within the meter as long as it can't earth or short with anything, is this correct?

[BroMikey]

Hi Turion,

I noticed the increasing 'drop' in RPM when I first examined the data. It curve fits the classic induction speed/load curve well. I'll post an image of a typical characteristic curve.

Also of interest considering the full load rating is 3450 RPM at 7.2 Amps, the starting RPM is 3460. You mentioned 7 Amps. That would indicate your freewheeling load, no bulbs switched on, is just shy of 3/4 hp.

Synchronous speed is 3600 RPM.

The load curve isn't a straight line. It is slightly curved with increasing downward curvature until you reach the knee, called 'breakdown torque', and once it reaches that point, the motor stalls and current skyrockets, tripping the klickson protector.

The kill-a-watt meter would confirm this.

Image showing shape of induction motor speed torque characteristic.

Split-Phase-induction-motor-Torque-Speed-Curve_copy_1117x999.png

Image from:

https://www.electrical4u.net/inducti...e-speed-curve/

Regards,
bi

The 115v motor pulls 805watts under load and without a load is 115v x 5amps= 575w but that motor is not suited for this project. A dc motor is something else and your wikipedia curves will not apply.

[bistander]

I also wanted to point out something about the data I posted from Greyland in case you didn’t notice

Starting RPM was 3460
Light #1 - 3440. 20 RPM drop
Light #2 - 3410. 30 RPM drop
Light #3 - 3359. 51 RPM drop
Light #4 - 3297. 62 RPM drop
Light #5 - 3120. 77 RPM drop

Although the loads are equal the effect on the motor is NOT. Hope that adds to your understanding of why this stuff is so important.

Hi Turion,

I noticed the increasing 'drop' in RPM when I first examined the data. It curve fits the classic induction speed/load curve well. I'll post an image of a typical characteristic curve.

Also of interest considering the full load rating is 3450 RPM at 7.2 Amps, the starting RPM is 3460. You mentioned 7 Amps. That would indicate your freewheeling load, no bulbs switched on, is just shy of 3/4 hp.

Synchronous speed is 3600 RPM.

The load curve isn't a straight line. It is slightly curved with increasing downward curvature until you reach the knee, called 'breakdown torque', and once it reaches that point, the motor stalls and current skyrockets, tripping the klickson protector.

The kill-a-watt meter would confirm this.

Image showing shape of induction motor speed torque characteristic.

Split-Phase-induction-motor-Torque-Speed-Curve_copy_1117x999.png

Image from:

https://www.electrical4u.net/inducti...e-speed-curve/

Regards,
bi

[bistander]

Hello people,
Sorry for butting in on this thread, this is off topic but not sure where to get help.
I am wondering if anyone can help here.
Problem
I have a normal panel amp meter 0-5amp and want to use it to measure amperage, but the voltage is around 3 to 4 thousand volts.
How should I hook it up?
Do I just pass the positive through it like a normal hook up and make sure the meter is well isolated, or is there another way of doing it.
Any advise would be greatly appreciated.

Hi Netica,

I'll reply here because I try hard to avoid threads started by a certain member. Analog panel meters are typically a moving coil type or other movement involving a coil. They have a very low resistance and essentially appear as a short circuit element in a circuit, so have a very low voltage drop across the meter terminals, even if there is a high voltage source for the circuit. Even though the meter has a very low potential difference across its terminals, it can still have a very high potential difference (voltage with respect to) other circuit nodes. For that reason it is usually wired adjacent to the most negative point (node, or negative of the power supply) of the circuit, which is typical ground, if you use a ground.

If it is a digital panel meter, it would use a csr (current sensing resistor) and a power supply for the led/lcd display. Such a device could galvanticly connect high voltage to the display circuit. I'd certainly check the specifications before using a digital meter in a high voltage circuit.

A fuse is a good idea. If you're unfamiliar or uncertain, you're welcome to post your schematic here and I'll comment.

Be careful out there,
bi

[bistander]

bi,
That is the entire point. You DON’T see increased load on the motor when the bulbs are switched on if you are running at the correct frequency. The load in NO WAY affects the performance of the motor. The motor neither speeds up nor slows down, nor does it draw more amps or fewer amps. And at the correct frequency the coil output is at its maximum. If the motor is speeding up when the load is attached, as in the debunk video, the output of the coil is less than maximum even though the motor is turning at a higher RPM and you would EXPECT it to output more. It DOESN’T.

We discussed gearing or pulleys for the AC setup, but I advised them to go back to DC for a couple reasons I believe to be significant. The original rotor had six, two inch magnets on it. The current rotor has 12 magnets each 3/4 in diameter. The original coils had three strands of 1000 feet. These coils have 12 strands wound in parallel with groups of four connected in series to increase capacitance per the Tesla patent.

The original machine was “neutral” at 2800 RPM. That was the bottom of the range. The top was over 3,000 where it would start speeding up under load. We have NO IDEA at what RPM the current machine is neutral. I would imagine it could be as low as 1800 or 2,000 RPM. And we have NO IDEA what the range is. At what speed does it begin to speed up under load and then the coil output drops off?

Based on what I have seen on the bench, the actual input required may be far less with these new coils and new rotor than what I have stated because less voltage is required to achieve the correct frequency. Yet the coil output will be at its maximum for that frequency.

When all these things have been determined with a DC motor, then we can go to an AC motor with the proper gearing to get the correct RPM. Otherwise we would be trying gear after gear to get the right RPM of the motor.

Hi Turion,

Bingo!

That is the entire point. You DON’T see increased load on the motor when the bulbs are switched on if you are running at the correct frequency. ...

Yep, that's what you've been saying. Excellent opportunity here and now to demonstrate it.
Good luck,
bi

[Turion]

bi,
That is the entire point. You DON’T see increased load on the motor when the bulbs are switched on if you are running at the correct frequency. The load in NO WAY affects the performance of the motor. The motor neither speeds up nor slows down, nor does it draw more amps or fewer amps. And at the correct frequency the coil output is at its maximum. If the motor is speeding up when the load is attached, as in the debunk video, the output of the coil is less than maximum even though the motor is turning at a higher RPM and you would EXPECT it to output more. It DOESN’T.

We discussed gearing or pulleys for the AC setup, but I advised them to go back to DC for a couple reasons I believe to be significant. The original rotor had six, two inch magnets on it. The current rotor has 12 magnets each 3/4 in diameter. The original coils had three strands of 1000 feet. These coils have 12 strands wound in parallel with groups of four connected in series to increase capacitance per the Tesla patent.

The original machine was “neutral” at 2800 RPM. That was the bottom of the range. The top was over 3,000 where it would start speeding up under load. We have NO IDEA at what RPM the current machine is neutral. I would imagine it could be as low as 1800 or 2,000 RPM. And we have NO IDEA what the range is. At what speed does it begin to speed up under load and then the coil output drops off?

Based on what I have seen on the bench, the actual input required may be far less with these new coils and new rotor than what I have stated because less voltage is required to achieve the correct frequency. Yet the coil output will be at its maximum for that frequency.

When all these things have been determined with a DC motor, then we can go to an AC motor with the proper gearing to get the correct RPM. Otherwise we would be trying gear after gear to get the right RPM of the motor.

[bistander]

We need to be able to control the speed of the motor, so the logical choice is to go back to the DC motor, where voltage will control the RPM more easily for simple setups and this prototype. Someone else can deal with the issue of motor speed at a later date. One other interesting fact is that the DC motor was using less than 400 watts to achieve what I wanted it to achieve, although output wasn't as high, and the AC motor is using closer to 800 watts and is still slowing down when put under load. Not what I want to see.

That AC motor is pulling more than 800 W when it slows down. The easy way to reduce speed to generator shaft is 5:4 pulley ratio. Yes, speed control allows easy adjustment and variable voltage to a DC motor is valid solution whereas variac/induction motor was not. But adjusting speed will not provide magic. You'll still see increasing load on the motor as more bulbs are switched on. I am glad you're finally collecting data to show this. Before induction motor is removed I'd love to see the 5 or 6 kill-a-watt meter readings for those data points.

Regards,
bi

[Turion]

We need to be able to control the speed of the motor, so the logical choice is to go back to the DC motor, where voltage will control the RPM more easily for simple setups and this prototype. Someone else can deal with the issue of motor speed at a later date. One other interesting fact is that the DC motor was using less than 400 watts to achieve what I wanted it to achieve, although output wasn't as high, and the AC motor is using closer to 800 watts and is still slowing down when put under load. Not what I want to see.

[bistander]

I've said for a while now that EVERY coil is a speed up under load coil (neutral coil) when run at the correct frequency. FREQUENCY is incredibly important. How do you CHANGE the frequency? Number of magnets on the rotor, or RPM of the rotor.

Here's some data for you from the tests Greyland's team ran today. They FINALLY got all six sets of lights working, but one set of lights, when put under load, would cause the motor to slow down, and it would drag down the whole system.There are six pairs of coils connected to six 300 watt bulbs, and the switches are numbered 1-6. Logical, right. Number six was the culprit that was causing the entire system to drag. They tried replacing the switch They tried rewiring the coils and checking all the connections. It still drug the system down.

It shouldn't be slowing down AT ALL, but it is. SO I asked them to turn on coil pair # 6 FIRST. They did, and then turned on the others in order. 6,1,2,3,4,5. When they got to the 5th set of coils and turned it on, the whole system drug down.

I asked them to measure the RPM after each coil pair was turned on.

Starting RPM was 3460

Light #1 - 3440

Light #2 - 3410

Light #3 - 3359

Light #4 - 3297

Light #5 - 3120

Light #6 - kills it

So my original machine with 6 of the 2" magnets and three strands of #23 each 1,000 feet long was "neutral" at 2800 rpm. Below that, when a load was attached, the motor would bog down. At 2800 there was no reaction. At about 2900 there was speed up under load. When I went to a 12 magnet rotor the necessary RPM for "neutral" dropped. I never experimented with higher RPM than what I needed to get the "neutral" effect. I appears there was more to learn.

These coils worked PERFECTLY with the MY1020 as the run motor, but their RPM wasn't this high. Let me run something by those who have experimented with these kinds of coils. Here is my thought. The motor here is turning the rotor TOO fast for these coils to react properly. What if there is a speed at which the coil drags. You speed up the rotor and you are neutral. You speed up more and you get "speed up under load." WHAT IF, when you speed up AGAIN you get to the point where the coil is dragging again. Above that there may be another range where neutral occurs again and above that another range where speed up under load occurs again. Just a thought. Some experimenting on the bench will tell if I am right or wrong. But if there was a speed at which these coils had drag, and there was a speed above that at which they sped up under load (and there was, because with the MY1020 motor, that was the range we were operating in at 36 volts because I have SEEN it.) Then the fact that they are dragging again at a higher rpm is interesting data. I told them to slow the thing down and see what happens. They need a Variac so they can control the AC motor speed. They are getting one. If any of you are experimenting with these kinds of coils, I thought that might be useful information for you to have.

Hi Turion,

Thanks for posting data. Very nice to see. Load bulb # vs RPM trend is typical of increasing load applied to an induction motor. Unfortunate that input to the induction motor wasn't recorded for each point. Could they possibly put a killawatt meter on the outlet to measure induction motor amps, watts, PF, etc?

The proper method for speed control of an induction motor is frequency control. A variac will slow down the induction motor by reducing its breakdown torque such that slip increases drastically. In other words, a variac will lower loaded RPM but cause motor to heat rapidly and stall at a much reduced load.

Again, thanks for data. Carry on.
bi

Ref: https://electronics.stackexchange.co...g-at-high-slip


JY6YU (1).jpg

[Turion]

We all do stupid things. Look at YOU, arguing about whether or not this stuff works and is worth anything.

[bistander]

I've been in the same garage when an air compressor tank failed. Easily could have injured or even killed a person. We were lucky. I know you don't believe in physics, Newton and all that, but a compromised pressure vessel should never be used. Ain't worth the hundred bucks to discard and replace.
bi

[Turion]

My dad and I replaced a broken tooth on a starter motor with A blob of JB weld and filed it down. No more problems with that starter working and it was still going strong five years later when my dad passed. I repaired a puncture in a compressor tank my dad threw away and I still have that compressor. It has its uses. How it will hold up if magnets get hot is another issue. This whole machine is just a proof of concept. Then I’ll turn it over to the engineers and let THEM figure out how to apply these concepts in a proper generator.

[bistander]

...
Over the next couple days I am going to pull the neutralization magnets back out of the machine and attach them to the circular plate on the end of the threaded rod with JB weld. My friend who built his OWN version of this machine said he is seeing the virtual S between the N magnets pull the magnet off the end of the threaded rod and they stick to the rotor between the two N magnets. ...

Hi Turion,
Your virtual poles are called consequent poles. With regards to your anticogging, the unexpected attraction of the magnets to the consequent poles will offset, at least to some degree, your anticogging scheme, won't it? Been wondering how determental cogging would be to breakaway and acceleration using the 5 core/22 magnet configuration in the first place. I guess you can probably adjust the 5 stator magnets back far enough to see.

And JBWeld? I don't like the stuff. I don't remember it ever working well for me. Think it'll hold if the magnets get hot? Or how long with thermal cycling? If a bond does fail, doesn't appear to be catastrophic, but who knows? At high speed, that rotor will have a lot of angular momentum.

Be safe,
bi

[Turion]

I assume the motor was simply drawing too many amps when the magnetic neutralization was out of adjustment. Once they got that squared away it no longer kicked off.

I will be having a long discussion with them at 3:00 today.
Edit: Discussion got postponed until tomorrow.

About this motor. I assume it that the more load you put on it, the more amps it will draw until it reaches the overload point and shuts off. I'm sure the boys probably overloaded it. But then they implemented magnetic neutralization properly, and the motor did not draw nearly as many amps. That is the benefit of magnetic neutralization

[bistander]

Here is a picture they sent me the other day of the motor nameplate when we were trying to figure out it’s amp rating.

Also, they sent me a video of them testing the coils. They turned on one light at a time, tested it, and turned it off. That is the recorded data I sent. Now I wasn’t there, but it appeared TO ME from the sound that each coil was slowing the motor a bit except ONE. And that coil sounded like it was causing the motor to speed up. I wouldn’t be surprised if THAT was the coil with the lowest output. Also, at the end of that video they flipped ALL the lights on and it sounded to me like the motor was slowing down. I also wanted RPM after each light is added

I have asked them to repeat some of these tests, as well as leaving the lights on as they flip each new one on.

if that one coil is indeed speeding up the motor when connected to a load, I would expect it to put out far below its max possible output. In my experience, that is exactly what happens. It needs to be neutral. F5C0ADB4-2D2D-4725-95F2-E665E8D01C75.jpeg

Cool. A single phase 2-pole induction motor rated 3/4 hp continuous output at 3450 RPM. Can be connected for different line voltage. At 115V it is rated at 7.2 amps. At rated, .892PF and 76.2% efficient. SF =1.25, so can run at 25% overload or 8.8A (115V). Rated for ambient temperatures up to 40°C. Insulation is class B, 90° C rise. ODP is open drip proof enclosure. Thermally protected, likely a klikson (bi metal switch) will trip on over current/time like a circuit breaker or on over temperature.
bi
{edit}
A few posts ago I mentioned PF (power factor). Here's a good example. 3/4 hp is rated mechanical power output, which is real power in watts, conversation factor of 745.6 watts/hp. So 3/4hp = 559.2W. That is output power.

Input power is calculated by current times voltage times PF = 7.2A * 115V * .892 = 738.58W. Efficiency = (output power) / (input power) * 100% = 559.2 W / 738.58W * 100% = 75.7% ( Nameplate spec is 76.2%, so it appears I have a calculation error of 1/2% likely due to rounding)