So I was able to snap some shots this morning before heading to work, the first is the output signal (pin 3) of the 555 at 200 us:

EDIT: I guess I could have made it easier and set it to 1ms, sorry, but if you look at picture #3 it is set to 200us and shows that it corresponds to 3 pulses as well.

The next is the same signal but at 500 us:

And for some reason the zoom function doesn't zoom in it only zooms out so I changed the sweep to look at the signals close up:

 

Ok thanks for the zoom.

The frequency is much too high. That's about 12kHz out of the 555.

What is the 1M adjusted to?
What is the timing capacitor value (the one in series with the 1M)?
Is the random part connected to pin 5? If it is disconnect it and connect only the 100n or 10n cap to Gnd, as discussed earlier.

 

I don't have the random attached, I hooked it to the circuit a couple days ago just to see the 555 output change and then I removed it and set it aside, pin 5 is connected to ground through the 100nF cap.

As for the 1M pot, I didn't install one to this board because radio shack was out of the 1M pots, I substituted it for a 1M resistor, and the cap is a 100nF.

I just realized that I have that 100 ohm resistor connected to pin 7 of the 555 (as outlined in the random schematic post #35) the 100 ohm resistor isn't in the schematic in post #22, do you think that this is the cause for the high frequency?

 

the 100 ohm resistor isn't in the schematic in post #22, do you think that this is the cause for the high frequency?

No.

What is the code on the timing capacitor? It's supposed to be 104. If it is 101, that'd be 100pF which would (more or less) match the 13kHz .

 

I will check when I go home for lunch. if that's the case I then all the 100 nF and 100pF are swapped in the schematic.

 

ok, I checked the caps and they are the right ones (ase 104) I even verified the ones one the random board and the are 101's....

oh... darn it!!! I just realized that the resistor isn't in fact a 1M its a 1k. how did I screw that up?!!

im in the process of changing it right now.

 

oh... darn it!!! I just realized that the resistor isn't in fact a 1M its a 1k. how did I screw that up?!!

Don't worry, happens to all of us.

 

Ok, this looks much better:

Notice that it is at 1 second sweep. and that the lines are more crisp. And the current draw is only 7 mA. Are we where we needed to be a week ago?

am I safe to go ahead with attaching the coils?

 

What is the coil resistance again? And what gauge did you use?

Here the diodes in parallel with the FETs come in to play. When the coils denergize they create a voltage peak. This voltage is clamped to the power supply voltage.

The electrolytic cap needs to be near the FETs.

I didn't see the whole layout but if something needs be improved we'll see it.

When you connect the coils and start the circuit the following has to observed.

total current, temperature of the FETs and you could also check the voltage over the coils (as you did with the resistors). If there are voltage peaks higher than 100V turn it off and check if the diodes are in place.

If the FETs heat up too much you may need a heatsink.

 

If you want to be extra cautious you could test only one coil at a time.

 

the coils are 7.5 ohms of resistance each and when I put them in parallel they are 3.8 ohms. I have four 10 ohm 10 watt resistors to drop it down to manageable levels. the question I have is placement of the resistors, can I get away with attaching resistors on the drain of T7 and T8 to accommodate all of the coils or do I have to have resistors in line of each set of coils?

edit: the gauge of the coils are 30awg.

 

Ok. I forgot about the resistors. Put 2 x 10 Ohm resistors in series, as you suggested between the drains of T7/T8 and the starpoint of the coils.
That's about 500mA total. If you want more current you'll need to put 2 series pairs of these resistor in parallel. That gives you about 1A.

Monitor the voltage on the transistors measuring from drain to source (this is what the diodes protect).

 

guess what? I landed on the moon!!

I put one 10 ohm resistor in line and I was getting magnetism. I then put the other 2 on line and it works like a champ. I didn't right down the total current draw but I will record that when I get home.

 

guess what? I landed on the moon!!

I put one 10 ohm resistor in line and I was getting magnetism. I then put the other 2 on line and it works like a champ. I didn't right down the total current draw but I will record that when I get home.

Nice. At 12V and 13,6Ohm you will be dissipating near 10W. Verify if it doesn't get too hot.

 

I will, I almost wish that I already had the magnet portion completed. I'm going to attempt to just set a magnet on a peice of plexiglass to see if the pulses will move it and keep it centered.

I still need to order the LED's....


Hey, how do you guys attach the thumbnails? I just read that the way I have been doing it is advised against.

And once I get everything working, can I upload a video of this contraption?

 

Hey, how do you guys attach the thumbnails? I just read that the way I have been doing it is advised against.

And once I get everything working, can I upload a video of this contraption?

Click on attachments (the small paper clip symbol), choose the file, then click on upload.

Done.

I then right click on the uploaded file and choose "copy link" (or something similar, my Mozilla is not in english), then I close this popup window and click on insert image. Then I insert the link to have the picture inside the post.

Why is the way you do it not recommended?

I don't think you can upload a video. You can only post a link to where the video is hosted, on Youtube for example.

I would however be very interested in seeing it working. If you can't/don't want to put it on youtube send it to me by email, I try to put it there and post the link here.

 

there is a sticky that I read somewhere on this forum suggesting that some people have slow internet connections and have to wait a long time to load pages with pictures, so as a courtesy to them its recommended to upload it as a thumbnail which afford them the option to open it or not.

I have a youtube account and I can upload a video when I get to that point. I appreciate your help thus far and I will still require some help.

I have definitely learned an immense amount of information from you. Although I do feel that I bypassed quite a bit of the basic knowledge, what someone would consider the foundation of this trade. I came in with an idea to go from A to B, and you provided the transportation while I sat in the passenger seat.

thank you

 

there is a sticky that I read somewhere on this forum suggesting that some people have slow internet connections and have to wait a long time to load pages with pictures, so as a courtesy to them its recommended to upload it as a thumbnail which afford them the option to open it or not.

This may be true for the BMP format. The PNG I upload have usually less than
50kb. A JPEG may go up to 150k maybe...

 

If you can't get the bicolor LEDs buy normal LEDs and mount two of them (with different colors) near the magnets. There is a way to turn only one on depending on the voltage applied to the coil.

 

Last night was nothing but playing around with the magnets, not much progress was made. However with me messing with it I realized that the resistor and coils are getting too hot, I need more resistance but in the form of magnetic coils. Can I get away with putting the coils in series to increase the resistance that way? Right now each coil has 7.5 ohms each and that will increase it to 0.91A. If I rewire them to 10 ohms each I'd be right at 0.6A.

So here’s it is with the coils wired in series, please let me know if you see anything wrong with it. (just rewired the coils to be in series)