@JCOX - While waiting on your parts and final circuit, here is something else to consider/work on. You will need a way to hold your magnet and allow it to spin. I'm pretty sure that just laying a magnet on the top plate of the 'project' is going to make it spin when power is applied.

A rotating motor of any type needs a central shaft, to keep the rotor(magnet in this case) from being thrown out of the stators/fields rotating magnetic force. With out a pivot point it is going to attract the magnet to the most powerful coil and stop rotating. And with hand wound coils one of them is bound to be stronger than others. Just something to think about.

I have been tinkering around with that, and think that I will use a magnetic bar, like the ones that chemist use in their stirrers and attach that to a center shaft that will be held by a bearing, I have everything that I need I just need to put it all together.

@Prandevou, I must of missed something in this thread, or maybe it was in a PM with you and JCOX.- Why a random voltage generation for the 555? I thought this was to simulate what is happening in a electric motor? Sorry for asking such a dumb question, but I'm lost now.

Honestly that was something that I wanted to incorporate, it's not necessary at all. It definitely isn't going to transfer over to the lesson. If everything works out, and I don't screw anything up, I want to make one for myself just to play around with and the random thing is going to be fun to play around with.

I'm almost 40 years old and this stuff excites and interests me!!

 

I'm almost 40 years old

Me too...

I personally think that in order to demonstrate how attraction/repulsion works the bar magnet needs to have the poles marked and there should be some kind of indication what pole is active at the coils, maybe with LEDs.

Just a thought.

 

I didn't find a 4075 OR gate in a DIP package at Future. A NOR does it too. (4025)

When I pull up the 4025 it looks totally different that what was drawn into the schematic, the picture shows that it has 14 pins, and the schematic shows only 4. It was the one you had in your parts list "MC14025BCPG" Is that the one that I want?


The 40106BD, the 40106 (not sure the difference between the 2) those are 14 pin IC’s as well.

There are so many variations of the 40175 I’m not sure on which one will work or if all of them will.

I can’t find LM258AD that is sold individually. The minimum order is 2500.

For all the capacitors, what voltage should be used?

And finally the resistors, what watt rating?

This is what I have so far..

 

Me too...

I personally think that in order to demonstrate how attraction/repulsion works the bar magnet needs to have the poles marked and there should be some kind of indication what pole is active at the coils, maybe with LEDs.

Just a thought.

Yeah I was thinking of red and green LED's across each electromagnet when it's north it'll be red and when south it'll be green. That's pretty easy right? can I just run red one direction and Green the other, just have to add resistors in line of the LED's to give it the proper voltage drop?? right?

Edit:
I meant to add the 2 LED's parallel to the coils to light up.

 

When I pull up the 4025 it looks totally different that what was drawn into the schematic, the picture shows that it has 14 pins, and the schematic shows only 4. It was the one you had in your parts list "MC14025BCPG" Is that the one that I want?


The 40106BD, the 40106 (not sure the difference between the 2) those are 14 pin IC’s as well.

There are so many variations of the 40175 I’m not sure on which one will work or if all of them will.

I can’t find LM258AD that is sold individually. The minimum order is 2500.

For all the capacitors, what voltage should be used?

And finally the resistors, what watt rating?

http://www.futureelectronics.com/en...es/triple-gate/Pages/6959951-MC14025BCPG.aspx
There are 3 gates inside.

http://www.futureelectronics.com/en...8045213-MC14106BCPG.aspx?CrossPart=CD40106BD3

http://www.futureelectronics.com/en...ic/4000-series/Pages/3593191-MC14175BCPG.aspx

http://www.futureelectronics.com/en/Technologies/Product.aspx?ProductID=LM258NSTMICRO3746666

Resistor wattage 1/4W or more.

Capacitor voltage 25V or more.
The 10uF and 1000uF are electrolytic caps, the others ceramic.
Take always the cheapest option. Shouldn't be a problem in your application.

I go back to work, will only be back in the evening.

 

Capacitor voltage 25V or more.
The 10uF and 1000uF are electrolytic caps, the others ceramic.

I have everything ready to order except for the 100 pF and 100 nF.. I can't find the through hole caps, do I just go with the surface mount ones? or am I missing something?

 

Yeah I was thinking of red and green LED's across each electromagnet when it's north it'll be red and when south it'll be green. That's pretty easy right? can I just run red one direction and Green the other, just have to add resistors in line of the LED's to give it the proper voltage drop?? right?

I'd suggest bi-color LEDs, red/green, so you only have one indicator, use a dropping resistor on it to limit current to below 20mA.

That way it would be red or green, or yellow if AC is on the coil.

 

I'm almost 40 years old and this stuff excites and interests me!!

I know what you mean. I'm going to be 64 in a couple of weeks and it excites me, especially when the guy's on the forum take the time to help and it works when its done!

You might ask Prandevou to add a switch and a potentiometer to the circuit so the speed can be varied either by the pot or the random voltage generator, so they can see both methods.

More work for Prandevou, but he's a good guy.

 

Finding parts on Future is horrible. It seems they don't want to sell....

100nF
http://www.futureelectronics.com/en/Technologies/Product.aspx?ProductID=SA105E104MARAVX4336418

100pF
http://www.futureelectronics.com/en/Technologies/Product.aspx?ProductID=SR212A101KARAVX1661594

In the shopping list you posted there are 16 MOSFETs. Why is this? In case you burn them?

EDIT:

LEDs
http://www.futureelectronics.com/en/Technologies/Product.aspx?ProductID=3BCBIVAR5001704
buy 510Ohm resistors for them.

 

No problem at all. I'm glad someone else is looking at this.
/QUOTE]

Yeah, I'm keeping my eye on you

 

In the shopping list you posted there are 16 MOSFETs. Why is this? In case you burn them?

To justify shipping, I ordered enough for 2. what I didn't order was those LED's and the potentiometer, I will try and call them tomorrow and hopefully have them add it to the order. Thanks

 

To justify shipping, I ordered enough for 2. what I didn't order was those LED's and the potentiometer, I will try and call them tomorrow and hopefully have them add it to the order. Thanks

Good luck with that, they are usually quick...

 

Good luck with that, they are usually quick...

You're not kidding! I sent them an email last night and called them first thing this morning. Like you said, it's already processed and shipped.

Oh well, I will check the local area, there is Fry's and a couple radio shacks in the area.

 

So on my lunch break, I was able to re-read the thread and have figured a few things out, things that were obvious to everyone else, I have done some research and noticed that the 3 CMOS IC's 4049BD_15V on the schematic are actually in one component, and that there are actually 6 of those in the 4049.

By using that logic I also deduced that the CMOS 4025BD has three of those in one chip. I wondered why your parts list only had 1 of those chips.

There are 3 gates inside.

^^that comment makes sense now
(I may not be the quickest at understanding things but I eventually come around) oh and the 40106.

One question that I have is: Does the VDD, and VSS pins need to be powered and grounded for those to work, or am I just using those sub components by themselves?

JCOX

 

One question that I have is: Does the VDD, and VSS pins need to be powered and grounded for those to work

Yes.

As for the layout, try to keep the logic part separated from the magnet part, i.e. the current that powers the gates should not ( or for the shortest distance possible) pass through traces/wires that power the magnets.
Initially, if you have an adjustable bench top power supply you could use that to power the magnets and a fixed 12V power supply for the logic.
This way you won't damage anything in case there are wiring errors.

 

Make sure you only tie the INPUTS of unused gates to ground.

Some people have misread and tied all unused PINS to ground, which kind of destroys the IC.

 

You realize you just invented the stepper motor? Had you did this years ago, you'd be rich and famous.

 

Actually he just invented the "3-phase stepper motor" which are only just now seeing a rersurgence of popularity in industry.

 

thanks for the input. so initially I will use 2 of those 12v power supplies. I will have to look at the schematic again to see where each power supply will go where. as for an adjustable power source I found some literature on the RS-7A and there is a trim pot that can be adjusted. so I took one apart and hooked a volt meter up to it and adjusted the pot both ways. the range that I have is 10.97v to 14.75v.
will that be enough range?

 

will that be enough range?

Actually not. Even though this power supply has a short circuit protection I would be starting with a lower voltage for the power part.
If this is not possible I would use a separated 12V power supply (as you suggested) for the IRF/magnet part and put a resistor of a few kOhm in series with "+", not connecting the magnets/LEDs. Then you could measure the voltage pulses at the points where you will connect the magnets too.

If there is any cross conduction between the FETs or wrong wiring, a voltage will appear over the series resistor, if everything is ok, no voltage will be present (since there is no current)