My 76,000 rpm pulsed dc motor

[mnsman]

Hello,

You may have mentioned this already, so forgive my asking again...what is the goal? What is it that you are trying to accomplish?


Merry Christmas....

Regards

erfinder,

Several things. I'm experimenting with the motor. My goals are: 1) attain top speed; 2) obtain optimum efficiency; 3) obtain maximum output. 4) study the effects of a high voltage discharge at a right angle to the magnetic field; 5) acoustic energy harvesting. Of course the holy grail is over unity. Will I do it? The odds are against it. The whole project is open source and easily reproducible. Building it and studying it is very educational. The most difficult part of reproducing this is making the stacked pancake drive coil. You can use whatever coil you like but I'm not sure you'll attain the same speed.

Merry Christmas to you too.

[erfinder]

erfinder,

Several things. I'm experimenting with the motor. My goals are: 1) attain top speed; 2) obtain optimum efficiency; 3) obtain maximum output. 4) study the effects of a high voltage discharge at a right angle to the magnetic field; 5) acoustic energy harvesting. Of course the holy grail is over unity. Will I do it? The odds are against it. The whole project is open source and easily reproducible. Building it and studying it is very educational. The most difficult part of reproducing this is making the stacked pancake drive coil. You can use whatever coil you like but I'm not sure you'll attain the same speed.

Merry Christmas to you too.

I find the project interesting... I'm thinking the speed has a lot to do with the dimensions of the machine, thats been my experience anyway...There have been a few experimenters who have built devices which operated at very high speeds, 300,000 rpm was the highest that I have seen so far I believe someone on this forum had a device which was even faster....I built a Bedini SG using a sphere magnet for the rotor and clocked it at around 50,000 rpm...I stopped working in that area and started trying to find a way to get that kind of speed in a large machine. Haven't gotten there yet....a work in progress....while working with these pulse circuits, specifically while trying to understand the Bedini SG, independent of what we are told about it, "what it can do", I began to focus my attention on some of the functions of the circuit which aren't being discussed in chat groups like this one. I'm mentioning one here as I believe it applies.

You have many goals, one or two of which mirror my own! In my trials, the circuit revealed that there were a few things going on that I needed to understand before I could set out on trying to accomplish any of those goals. Among other things I learned that the SG is a NO CEMF prime mover. When the shaft of the device is loaded, there is no measurable increase in consumption, unlike the conventional pulse motor circuit, there is a dramatic decrease in consumption! Generator action which is more or less responsible for the increase in consumption is for lack of a better way of putting it....neutralized. In my opinion, this phenomena should be a fundamental function of any electrically supplied prime mover. Have you noted this effect in your design?

Regards

[quantumuppercut]

... Among other things I learned that the SG is a NO CEMF prime mover. When the shaft of the device is loaded, there is no measurable increase in consumption, unlike the conventional pulse motor circuit, there is a dramatic decrease in consumption! Generator action which is more or less responsible for the increase in consumption is for lack of a better way of putting it....neutralized. In my opinion, this phenomena should be a fundamental function of any electrically supplied prime mover. Have you noted this effect in your design?

Regards

I also think this is interesting and should be of further exploit. I also found the answer to my question about BEMF being higher than the source voltage.

Notes on Motors

"...Induced voltage may momentarily be higher than the applied voltage, causing the motor to act as a generator..."

[OrionLightShip]

Looking at your schematic and your design goals I came up with one thing.
I haven't worked with Arduino in any fashion that required anything but the standard compiler and timing code. If I remember correctly, the wait 1 statement is 1 millisecond. At 1K frequency, you are at that limit and adding in processor time, your friend is right, it is too slow. I haven't researched anything on this, just using what is in my head from memory.

Since the processor runs at 8 mhz, 16 mhz, or whatever; perhaps the interrupt function does not have the same time division constraint?

The only thing I can add is that regardless what platform or code you use, you could perhaps split the hall effect sensor into two outputs and simply let the motor free run. This would free up the controller to take care of all the other functions involving the tach display, spark gap, etc....


Orion

[OrionLightShip]

Still on my list is to build several different coils for testing... to include the modified starship coil as suggested by Orion. The modified starship coil will contain in it's core a removeable pancake coil. These two coils can be run in series or parallel.

Now that is sheer genius...no wasted space for maximum effect.

[mnsman]

There have been a few experimenters who have built devices which operated at very high speeds, 300,000 rpm was the highest that I have seen so far I believe someone on this forum had a device which was even faster.

I've seen the sphere motors run that fast but not one on a shaft. If on a shaft can you please share where I can find an example.

Among other things I learned that the SG is a NO CEMF prime mover. When the shaft of the device is loaded, there is no measurable increase in consumption, unlike the conventional pulse motor circuit, there is a dramatic decrease in consumption! Generator action which is more or less responsible for the increase in consumption is for lack of a better way of putting it....neutralized. In my opinion, this phenomena should be a fundamental function of any electrically supplied prime mover. Have you noted this effect in your design?

By loading the shaft I presume that you meant loading the system by adding a pickup coil. If this is the case I have not done so at this point. I have a nearly identical coil that I can add but haven't done so as of yet. I've loaded the system by drawing from the recovery capacitor with limited success.


MERRY CHRISTMAS everyone!

[mnsman]

Now that is sheer genius...no wasted space for maximum effect.

Not sure about genius... I'm the biggest dummy I know. lol I'll give it a go. Bought some rolls of 1/4" copper tape a few mils thick (not sure of thickness at the moment) which is normally used for shielding. Eventually I plan on rolling the tape into pancake coils with 1/4" mylar tape between layers as an insulator. A couple of those pancakes stacked will be the core of the modified starship. Thanks for your inspiration Orion and glad to see you've stuck around.

My pile of blown power mosfets keeps growing. Not having much luck lately with getting control over this beast. I've got to solve the problem of blowing up fets it's costing me big $$. Can't run off of power supply with the 1000V fets- the back-feed into the p.s. is making it go wonkers. Using more than one bat at turn on it's too big of a shock to the system and blows fets in a hurry. Need a power on circuit to gradually apply full bat power. Of course a micro controller should alleviate this problem given it's pwm.

There's always one more thing to try. lol

[soundiceuk]

Hi, you are welcome to use my driver circuit, if it is of any help:



Also maybe these circuits may be of help:

RMCybernetics - DIY Homemade Ignition Coil Driver

or these may be of help:

Cyber Circuits - RMCybernetics Shop

Have you got any good pictures of your setup. I would like to experiment. I have quite a number of neodymium magnets lying around.

Cheers

[OrionLightShip]

Not sure PWM will help or not..shorter pulses may cause even higher spikes.

You could do PWM very easily with a hall sensor triggered 555 with adjustable pulse width.

optoisolate both the hall and the 555 output
use high wattage external transient voltage protection diodes
use a mosfet driver

the internal TVP diodes are not rated high enough to protect you from what you are doing... just my opinion as to why you keep blowing mosfets

I don't know what those big 1500 watt TVP's cost but I'm thinking as a permanet solution...they might save you money in the long run

[soundiceuk]

Sorry found some of your other videos and can see what you are doing.

Somewhat similar to Jorge aka "skycollection" on youtube.

I believe using a bifilar pancake coil pickup you can make more wattage than your input. I have been trying to communicate this to Jorge.

What amperage is your current driver using?

Is it the high voltage spikes that are blowing the fets? The transistor in my circuit has never blown. The circuit was designed for this purpose. The fuse goes first.

[mnsman]

Looking at your schematic and your design goals I came up with one thing.
I haven't worked with Arduino in any fashion that required anything but the standard compiler and timing code. If I remember correctly, the wait 1 statement is 1 millisecond. At 1K frequency, you are at that limit and adding in processor time, your friend is right, it is too slow. I haven't researched anything on this, just using what is in my head from memory.

Since the processor runs at 8 mhz, 16 mhz, or whatever; perhaps the interrupt function does not have the same time division constraint?

The only thing I can add is that regardless what platform or code you use, you could perhaps split the hall effect sensor into two outputs and simply let the motor free run. This would free up the controller to take care of all the other functions involving the tach display, spark gap, etc....


Orion

I think the Arduino is capable of the task but I would be forced to learn assembly. Years ago I programmed in assembly for the 8088 processor with ms-dos... I know I'm dating myself. I really enjoyed doing that but there was a big learning curve and the same would apply for the Arduino. Don't really want to have to learn all of the assembly commands and registers etc. Hopefully the AVR-MT-128 micro-controller solution will pan out. Still waiting on a demo of the controller next week.

I made a couple modifications of the drawing. Most notible is that I placed a diode across the primary of the HV transformer instead of sending the coil discharge to a cap.

[mnsman]

Hi, you are welcome to use my driver circuit, if it is of any help:



Also maybe these circuits may be of help:

RMCybernetics - DIY Homemade Ignition Coil Driver

or these may be of help:

Cyber Circuits - RMCybernetics Shop

Have you got any good pictures of your setup. I would like to experiment. I have quite a number of neodymium magnets lying around.

Cheers

You and Orion are coming at me fast and furious today. lol Thanks for the schematic. I have a circuit that I built years ago somewhere around here that aloud me to adjust delay and duty cycle manually with some variable resistors. Two 555- first delay and second duty. I don't want to do that again. I'd rather have a micro controller do it for me automatically. Another advantage with the controller is the ability to control the timing of the load discharge as depicted in the above schematic I just posted. The biggest problem I have at the moment is the fets blowing with such high input voltage.

[OrionLightShip]

thought you were having trouble with the BEMF....

thought you were using 12v input...I must have missed something

[mnsman]

Not sure PWM will help or not..shorter pulses may cause even higher spikes.

Don't say that. My thinking was that a shorter pulse duration would mean a smaller charge across the coil and consequently a smaller discharge.

You could do PWM very easily with a hall sensor triggered 555 with adjustable pulse width.

optoisolate both the hall and the 555 output
use high wattage external transient voltage protection diodes
use a mosfet driver

See my last post regarding 555.

the internal TVP diodes are not rated high enough to protect you from what you are doing... just my opinion as to why you keep blowing mosfets

I don't know what those big 1500 watt TVP's cost but I'm thinking as a permanet solution...they might save you money in the long run

Agreed about internal TVP. A cursory look into external TVP's came up with either too high of a rating or too low. Need to look into that more.

[OrionLightShip]

I'm probably wrong about the spikes from a short pulse

One more stupid idea...use an rc integrator on the gate trigger input to ramp up to full on