Hey all-

New here but am looking for some thoughts. I'm trying to piece together an electromagnet experiment similar to a gauss rifle. I'd like the project to be complete with data gathering components but I'm stuck on the microcontroller. I can get most of the electronic control and sensor components at a reasonable price for a total propagation delay of 10-20ns. I'd like a microcontroller that I could program in assembly, easily access a parallel bus to interact with the sensors/drivers, and record some data from the same bus or a different one. I know that 20ns response time is 50Mhz, which is a high speed for common kits, and that I'll blow 20 cycles minimum which reduces a 50Mhz micro to 400ns response time. While this is all still really fast, I want to go faster. It's just a ten year old high school bet at this phase, but I want to be really accurate with the systems response time to the sensors, and build it modular so I can maintain it and expect it to be modern for a while. I have programmed both motos and atmels in college, multiple architectures. I guess it's been a minute and I haven't done this in a while, let alone as a hobby and on my own dime. I really just want to close this chapter and see if I can still design this system as it seems the sensor cost which was previously insurmountable has become quite affordable. I do know what I'm getting into, I just want to get the micro right now that the other parts are plausible. I could prob settle for 100ns, but I'd like to get it as small as possible. Yes I overbuild . If the costs are getting exponential I will just grab an atmel dev board. I think this should be doable under a grand though.

-Thumbs

 

Is this thing on a large enough scale to be dangerous? Because there is a rule here against rail guns and suchlike things. Balls hitting magnets doesn't sound too scary, but then why do you want a super-fast processor for a desktop toy?

 

The scale itself for me? No. I know what I'm diving into here and it scares the snot out of me so I'm being very safe. I've been working on the idea since high school and I have a BS in electrical engineering from a prominent U.S. University. Scale to be dangerous, yes. This is not a desktop toy. The design of every other piece is well thought out on the scale, but I will not say it is safe, and therefore many precautions need to be taken in this endeavor of mine.

Railgun, no. The intention here is not to magnetically pro-pulse an object ridiculously fast for intentions of propelling a device ridiculously fast unethically and dangerously (very very dangerously). This is why I have not divulged the rest of the components as the system could be used in this manner. The intent is to better understand the implications of a moving magnetic field hopefully to a magnetic object, like a motor on a linear scale. Yes there is always the possibility of unexpected ejection if a sensor fails to record a proper position and compensate the flux and is why safety is the most important measure in an experiment like this. I'm bound by a code of ethics and am only seeking the answer to my question. I have a couple interesting electromagnetic applications that depend on me first learning how to properly manipulate the flux (firsthand with data). I wanted to build the design in college and even went so far as to consider contacting the FCC in regards to frequency distortion as I lived near an airport and wanted to execute properly.

In short, if you think this post is improperly placed for public view then please close it. I assure you I have thought about the design and the ethics thoroughly and am not opposed to running on PMs from here if anyone can assist.

 

Hey Thumbs. I hear ya as to the safety concerns of this device, but that's a choice for the mods to make.

As much as I love micros this sounds like staying in the analog domain may be a better choice as each accelerating magnet can be in it's own loop.

Microchip makes PIC32's that run up to 80MHz with 1 cycle per instruction, and they can acquire up to 1M (mega) samples/second, or 1 every uS. They you have (up to) 80 instructions per uS to process this data. I would not consider doing this in assembly especially when MC gives away a fine C compiler to use, plus this is an extensive set of assembly instructions (meaning I have never even looked at them).

I still think that may be pushing things to go pure digital control. But these projects are interesting and it looks like you are still in the concept phase of your project.

 

I am very pleased at how the OP gives out a responsible profile and seems to be understanding the situation. A factor for closing threads is the poster's experience and here it seems to be adequate.

Other than that, even if the application is to measure magnetic propulsion, I hope there will be no such details in this thread. If the main issue is the data measurement, I see no problem for the interestingly challenging problem to be discussed.

 

Yeah I've been considering run of the mill kits at 50-80 Mhz. At that point I'd likely go with an Atmel. Truth be told I am also interested in observing power use and efficiency with differing power application techniques. In the end the good EE experiments include these measurements as well. That's really the reasoning behind the speed of the measurements. I want to be able to try different algorithms which may factor into a mark 14 version as an electric car motor with re-cyclical braking (something I always thought was neat 10 years ago ). With that you need a very good understanding of how the magnetic flux is being manipulated to roll it back into electrical energy. All this complication rules out analog for a one man design team though IMHO . Although something built on analog that could do all that would be something I'd definitely like to see in person .