OK, and interesting. Now, as an alternative that will allow much greater flexibility and quite a lot better reliability, I suggest using a small PLC, (Programmable Logic Controller). First reason is that as a complete package there is no need to experiment with trying to get it to do what you want. Second reason is that the hardware issues are already solved for you, including the package, power, and connections. And from the right supplier, the programming software is a part of the package, so no guessing how to make a timer or a counter work. That will allow experimenting with waveforms and amplitudes to be the focus.
I recommend Automation Direct as the supplier because they are not only honest, but also they are good with customer assistance. And the smaller simpler PLCs probably cost the same as the bunch of experimental hardware that will still need to be packaged and powered.

 

The reason is I am powering an electromagnet. I checked that the maximum value was 2500 uTesla. I suppose it is safe. Still prolonged exposure I am not sure since it runs 24/7. I am not sure if a microcontroller can operate in close proximity to the electromagnet. Or I have to put the MCU at a different location and run wires to the electromagnet. In any case I like to have a discrete component setup before trying out the microcontroller.

You're more likely to have issues with the multi-component solution, as there are many more opportunities for EMI ingress. Its unlikely the electromagnet will have an impact on the MCU. The emf generated at your highest frequency is <<0.1v even if right next to it.

Do you have a link to the magnet you're using? 2500uT = 25Gauss is a tiny magnetic field, though large compared to the earth (65uT at poles, 25uT at equator. 50uT here in London). By contrast an N52 magnet 20mm dia x 5mm thick is some 5000G or 0.5T

 

And the smaller simpler PLCs probably cost the same as the bunch of experimental hardware that will still need to be packaged and powered.

Really Bill? A basic Arduino-compatible PLC, programmed via the Arduino IDE so a roughly comparable setup, with 24v PSU, and 1 basic shield - their 'starter kit' - is $288.

And now we know it's powering an electromagnet as the end goal potentially simplifies things further as we don't need a high-side switch.

 

Really Bill? A basic Arduino-compatible PLC, programmed via the Arduino IDE so a roughly comparable setup, with 24v PSU, and 1 basic shield - their 'starter kit' - is $288.

And now we know it's powering an electromagnet as the end goal potentially simplifies things further as we don't need a high-side switch.

That might be a bit more than the price of the PLC I was visualizing.

 

That might be a bit more than the price of the PLC I was visualizing.

Can you point to something more reasonable then, ready to roll with programming environment, power supply (or low-power 5-12v operation to utilize existing) and suitable outputs.

 

You're more likely to have issues with the multi-component solution, as there are many more opportunities for EMI ingress. Its unlikely the electromagnet will have an impact on the MCU. The emf generated at your highest frequency is <<0.1v even if right next to it.

Do you have a link to the magnet you're using? 2500uT = 25Gauss is a tiny magnetic field, though large compared to the earth (65uT at poles, 25uT at equator. 50uT here in London). By contrast an N52 magnet 20mm dia x 5mm thick is some 5000G or 0.5T

I suppose the program is stored into the microcontroller in flash memory. That is why I suspected that it could be affected by the magnetic field. Ofcourse 2500 uT is only at the poles where there is maximum field intensity and still that could not be of a magnitude that would affect the program in the MCU. I am keeping the control circuit at a safe distance. Another reason is I will be taking time to set up my PC, learn programming and get all the setup running it takes time and energy meanwhile I want to get the control circuit working and the magnet running in a shorter period of time for now while I get the MCU approach ready.

That is not a commercially available electromagnet I made two one with 3 mm core dia of 2.5 meter length with insulated
Copper wire and one more with 0.5 meter length with wire wound around it. I am using a buck converter to power it. Its already running and working in manual mode I just change the frequencies manually by switching the 555 timer units. The ouput of the 555 goes to the buck converter voltage pot wiper pin and that produces the pulsing effect.

 

That is not a commercially available electromagnet I made two one with 3 mm core dia of 2.5 meter length with insulated
Copper wire and one more with 0.5 meter length with wire wound around it

So the magnet is 2.5m long and 3mm core? What material is the core? how any turns of wire over what length & what gauge wire?
Same info for 0.5m one...

 

So the magnet is 2.5m long and 3mm core? What material is the core? how any turns of wire over what length & what gauge wire?
Same info for 0.5m one...

Core is a flexible multistranded GI wire core for first EM, 0.75 sq. mm of pvc insulated copper wire wound around. I used about 12 to 15 meters of copper wire didnt count the turns when I wound it. For the second EM its a stiff non flexible 5 mm GI wire and I used 1.5 sq mm pvc insulated wire to wind.

 

Core is a flexible multistranded GI wire core for first EM, 0.75 sq. mm of pvc insulated copper wire wound around. I used about 12 to 15 meters of copper wire didnt count the turns when I wound it. For the second EM its a stiff non flexible 5 mm GI wire and I used 1.5 sq mm pvc insulated wire to wind.

Assuming your PVC coated 20awg wire is a typical 1.25mm diameter then 1 turn is 1.25mm wide and 4.25mm diameter or 13.5mm long approx. 12m of wire would be 12/0.0135 = 890 turns covering about 890 * .00125 = 1.1m of core. 15m would be approx 1,100 turns covering 1.37m of core. Does either of those sound about right? Assuming the bigger of the two, the magnetic field at the centre of the coil @ 1.5A and taking the relative permeability of the core as μr = 500 would be approx:

\(Φ = u_0 * u_r * N * I /L = 4\pi^{-7} * 500 * 1100 * 1.5 /1.37 = 0.76T \)

This is rather larger than your 2500μT ! How did you calculate yours?

Also the resistance of that coil is very small. How are you limiting current to 1.5A?

 

This is rather larger than your 2500μT ! How did you calculate yours?

Also the resistance of that coil is very small. How are you limiting current to 1.5A?

Actually the current is 3.75 Amperes supplied through a buck converter. I didnt calculate the magnetic field. I checked it at the poles using the magnetic field sensor on my android phone. Actually the two electromagnets are separated in space, electrically connected in series.

This is the buck converter

https://roboticsdna.in/product/5a-c...ery-charging-module/?src=google&kwd=&adgroup={adgroup}&device=m&campaign={campaign}&adgroup={adgroup}&keyword=&matchtype=&gad_source=1&gclid=Cj0KCQjwsaqzBhDdARIsAK2gqnc-dNGUcHFlG99kSA0_CZl94WJYlfxBa_GTMgZkoPmcQgCOkWlgOA8aAi6oEALw_wcB

 

Yes that CC/CV buck converter should work OK give sufficient input. What are you powering it from?

Can you post a picture of the two electromagnets?

 

What are you powering it from?

Its a normal 19 Volt dc adaptor for laptop charger.

The electromagnet concept is based on Vastu Shastra, an ancient Vedic science of using 5 elements of nature to harness the positive magnetic energy. Its complicated I have been researching into it as a hobbyist for over 11 years and now practically trying to understand how it works. For the electromagnets to work correctly the 5 elements in the house has to be in harmony. I may sound like a con but this is why I didn't want to go into the details.

As for the picture the second EM I put in a metal box filled with stones and sealed it bringing the wires out. The core is this 5mm GI wire

The first one is flexible and it can be changed to various shapes. This is the 3mm flexible wire rope I got it from amazon and its a 0.75 sq.mm wire used for house wiring wound around it. I tried with normal insulated copper wire used for windings but the insulation gets ripped off so it needed stronger coating. I'm sure you can visualize it. 2.5 meters of 3 mm core wound by this pvc coated wire.


I also found powering it produces healing effects I had various health issues and it seems to reduce the negativities but once I power it off it stops healing so I am now completely dependent on it. Also it doesn't seem to be permanent the magnetic energy seems to get saturated after sometime on contiuous running and loses its healing effect so I am trying to cycle the frequencies. It is only in testing stage I am trying to figure out how this energy works and it might be a long journey. I wouldn't recommend anyone trying similar thing out since doing it wrongly could cause the opposite adverse effects. The magnetic poles if they get reversed without applying concepts.

Starting from the buck converter a lot of help has been offered here in this forum by the members and ideas from Crutschow helped a lot. It wouldn't be fair on my part to not disclose whatever I am doing and keep asking for ideas. Anyways I have researched on Vastu Shastra for over a decade and trying to apply the concepts. Here for anyone who doesn't believe in it, dismiss it as myth I am not forcing any concept on anyone I am doing this for my personal use only.

Also apologize for going out of forum rules these are not even related to circuits just other members are curious to know about this project so I gave an explanation.

 

Also it doesn't seem to be permanent the magnetic energy seems to get saturated after sometime on contiuous running and loses its healing effect so I am trying to cycle the frequencies.

I suspect that might be the wrong material for the core. If its steel not soft iron it will gradually magnetize and you'll loose some of the variation due to pulsing, and therefore the impact on the nervous system will be reduced. Amazon link?

Here for anyone who doesn't believe in it, dismiss it as myth I am not forcing any concept on anyone I am doing this for my personal use only.

I'm a research student (yeah, at 66!) at UCL in the Centre for Rehabilitation & Assistive Technology. A colleague of mine is a specialist in TransCranial Magnetic Stimulation (TCMS) where a fairly powerful magnetic pulse is applied across the skull. This induces electrical signals in the brain's circuits. Though the exact mechanism is not fully understood it is known to have some very specific benefits, including reducing the scale & impact of epileptic fits and reducing depression, without the side effects of drugs.. I've tried it and the effects are weird. It works better, and is safer than, Electro-Convulsive Therapy (ECT) which requires much higher voltages and currents because the skull is a significant insulator, as is dry skin. I use a muscle stimulator to try and maintain muscle tone and good blood flow in my paralysed legs and this needs voltages of upwards of 120v to push 80mA through the skin to stimulate the thigh and calf nerves. Its a bit of a sledge-hammer to crack a nut but less invasive than opening up the legs to attach stimulation directly to the nerve root! Recently we've been working with a modified TCMS machine to see if we can get the same stimulation that way, as skin and muscle are transparent to magnetic pulses. Blood is ferromagnetic and is known to respond to magnetic fields (the basis of MRI machines) but the amount of iron carried in the blood cell is very small so extremely large magnetic fields are needed, hence the massive superconducting magnets needed for MRI. So I for one won't dismiss the concept at least. Whether you can achieve therapeutic value with low levels of magnetism, or whether the result is purely psychosomatic, is a separate question...

 

I suspect that might be the wrong material for the core. If its steel not soft iron it will gradually magnetize and you'll loose some of the variation due to pulsing, and therefore the impact on the nervous system will be reduced. Amazon link?

Teniq 3mm Dia. 10M Length galvanized iron steel wire rope for Hoisting https://amzn.in/d/58GPkYh

It says galvanised iron. But that is what I found most suitable that is readily available in the market.

Good to know that you understand that magnetic field has healing effects and that you have expertise on that.

I am not into sophisticated industrial equipments as you can see my equipments are simple and hobbyist level project. I did learn information about the magnetic field used for medical purposes.

But I suppose from what I see in my experiment, I do not see the intensity or the magnitude of the magnetic field that is producing the healing effect but its kind of its "quality" and its polarity I may sound absurd here but I have very low intensity magnetic field and it seems to clear out my autoimmune conditions and prostate problems. So I suppose the approach has similar concepts but they diverge in my case. When I power it off the problems return it is not a permanent solution but I also stopped taking medications for those conditions. As I said if run for about 4 to 5 days continuously at one frequency then it seems to lose its healing effect. Then I tried to cycle between two different frequencies it worked again for about a week fine and again got saturated and lost its positive effects. So I decided to cycle 7 frequencies.

 

I can verify that blood is at least somewhat ferro-magnetic. I certainly felt the magnetic pulses during an MRI of a ripped-apart shoulder joint a bunch of years ago. The feeling coincided with the audible sound from the powerful electromagnet in the machine. Not really painful, but certainly felt.

 

Teniq 3mm Dia. 10M Length galvanized iron steel wire rope for Hoisting https://amzn.in/d/58GPkYh

It says galvanised iron. But that is what I found most suitable that is readily available in the market.

Good to know that you understand that magnetic field has healing effects and that you have expertise on that.

I am not into sophisticated industrial equipments as you can see my equipments are simple and hobbyist level project. I did learn information about the magnetic field used for medical purposes.

But I suppose from what I see in my experiment, I do not see the intensity or the magnitude of the magnetic field that is producing the healing effect but its kind of its "quality" and its polarity I may sound absurd here but I have very low intensity magnetic field and it seems to clear out my autoimmune conditions and prostate problems. So I suppose the approach has similar concepts but they diverge in my case. When I power it off the problems return it is not a permanent solution but I also stopped taking medications for those conditions. As I said if run for about 4 to 5 days continuously at one frequency then it seems to lose its healing effect. Then I tried to cycle between two different frequencies it worked again for about a week fine and again got saturated and lost its positive effects. So I decided to cycle 7 frequencies.

Have you been logging your results? Assuming your doing something novel, you should try to make this into an actual experiment. Then, if you get unbiased results, you can potentially submit this method for further testing by professionals. This is the idea behind being a citizen scientist.

One of the best ways you can improve your results is by introducing randomness into your trials. As a designer, you have a strong personal interest in making your contraption work so there is a high probability of placebo.

As for the project itself, I have a moderate form of arthritis so I understand the willingness to try new things especially if it means stopping medications. That being said, whatever you are doing may in fact be damaging your body more in the long term than any temporary effects you feel now. It would be prudent of you to slowly adjust your parameters to account for gradual changes that are happening in the body which are not immediately obvious. For example, you are changing frequencies a lot.. are you sure you have given enough time in that maybe it's working but you just don't feel it? There is the important difference between pain relief and actual healing. Food for thought.

 

Have you been logging your results? Assuming your doing something novel, you should try to make this into an actual experiment. Then, if you get unbiased results, you can potentially submit this method for further testing by professionals. This is the idea behind being a citizen scientist.

One of the best ways you can improve your results is by introducing randomness into your trials. As a designer, you have a strong personal interest in making your contraption work so there is a high probability of placebo.

As for the project itself, I have a moderate form of arthritis so I understand the willingness to try new things especially if it means stopping medications. That being said, whatever you are doing may in fact be damaging your body more in the long term than any temporary effects you feel now. It would be prudent of you to slowly adjust your parameters to account for gradual changes that are happening in the body which are not immediately obvious. For example, you are changing frequencies a lot.. are you sure you have given enough time in that maybe it's working but you just don't feel it? There is the important difference between pain relief and actual healing. Food for thought.

Thanks for the advice I do realise that these healing effects could be temporary and I could be risking health for the long run. Also the medications I take do not give a permanent solution. I am not sure if this method can be submitted anywhere. It is based on Vastu Shastra which is kind of like Feng Shui and if it has to work, the house or place where the magnet works has to be Compliant to that. Meaning all 5 elements of nature have to be in perfect harmony in the right directions. I have spent a lot of money in altering the house to make it compatible with those Vastu rules its a normal practice in India to follow these rules in building houses.

I suppose the reason it works is because of this. The magnetic field that heals is not the field that is produced by the electromagnet but the field that is attracted by it. Actual concept of Vastu is that as long as the elements of nature are in order everything will be fine and once they are out of order chaos ensues. I suppose that is what happens here when it is powered off. Still I am diving into it and trying to learn how that energy works.

 

the program can be run in real time unlike constantly uploading to an Arduino.

What do you mean by this? You upload the sketch once from the IDE and there’s no need to upload it again.

 

What do you mean by this? You upload the sketch once from the IDE and there’s no need to upload it again.

In this screenshot I ran the script then stopped it after 9 seconds. The script is named app.py and the command via Thonny to run it is %Run app.py which executes almost instantly. I'm not showing a microcontroller in this example but the same idea works with the Pico code. It can be uploaded directly to the device or run on the fly via Thonny. If it's run on the fly, the script isn't permanently saved to the device. I really like this feature because you can start and stop the program (and edit) with little to no wait time. It basically runs the program from memory as opposed to mass storage.

 

OK, I am guessing that the sequential control portion of the question has been either answered or set aside. Certainly a small PLC would allow it to run 24/7 without any problems, and program changes could be made and loaded easily. And timer settings could be changed while running.