1 Phase Magnetic Delay Induction Motor
I want to desribe how I made the Tesla patent no. 524,426 to function.
The work on the motor started about a year ago, and before that also some failed attempts. The first mistake I did was to have too thin wire, and too small a magnetic field for the rotor. I understood I had to design a series of coils that first of all did not burn up at mains 50 hertz, 230V AC pressure, meaning the Ohm was too low and the Ampere too high, but also producing a strong enough magnetic field to grab onto the iron disk rotor. From experience I know that about 40-60 ohm is sufficient using a AWG 24 wire ( 0.5 mm diameter crossection ) . So I coiled up 4 coils of 60 ohm / 4 coils = 15 ohm . the coils used is actually 15.5 ohms however and wired in series, basically 1158 turns, AWG24 Ø = 0.511 mm wire diameter. Coil chassy is a steel pipe about 42 mm diameter and 40 mm long between the faces.
Tesla decribes in the patent that using long iron cores will produce a phase differance in relation to a short iron core with a coil. To make the motor function it has to be understood how the coils are ordered, this is not desribed clearly in the patent, but if one pair of coils that are diameterically opposed, share the magnetic field like one bar magnet that is split on the middle. and so are the pair on 90 degrees. It is of great importance to wind the coils in the same manner, that is to be certain where the IN wire enters, and where the OUT wire exits, and wind all the coils either from top left to right bottom or vice versa, to keep track of the magnetic fields when placing the electromagnets .
The long core coils was changed after the first initial failed tests, I wound them out of the coil chassy, saved the wire and reused it on a new coil chassys, that was longer and could hold more turns. I figured the magnetic field was too low. and I made a longer chassy, and added another coil in parallell ontop of the first. the initial turns was 1158 turns, but I then had to make a choise, shall I wire the next coil with another 1158 turns or should I constrain myself to 15.5 ohm. since its a parallell wiring, I went for constrining the ohm, so the coil ontop of the other didnt have 1158 turns and maybe 30 ohm. the ohm increases because the increased diameter. So the outer parallell coil has about 640 turns.This works as seen on the video, but not essential. What I later realized is that I had been sent a wire that was maybe AWG25 or 26. being 1 thenth of a millimeter thinner. increasing the resistance drastically, with excellent service from the wire provider, I got a refund wire of proper diameter and labelling. It is worth mentioning that the Resistance is one thing, but in an AC coil its actually the effective resistance ( or Real resistance ) in Impedance that is the important factor, and the Impedance is always larger than the resistance. Just like the Hypothenus is always longer than the kateths of a triangle .
Previously I wrote 1240 turns but is an error due to the fact that I uncoiled the origional wire chassy of 1158 turns onto a coil chassy with a longer core, then there was less layers and got more turns with the same lenght of wire.
11.04.2017
I disconnected the paralllell windings on the long core coils and only used the 1158 turns of wire on all 4 coils. And I replaced the short core irons cores with wood cylinders. I then managed to move the short cores much closer to the rotor, and also have the long cores and its belonging coils very close to the rotor.
The speed of the rotor is very low, and the tork is also poor, but this may be that is only one thin steel disk of rotor. I will add more layers of sheet iron and a bearing to the rotor to check if it speeds up and gives a more decent tork.
Nikola Tesla himself says in his notes somewhere that this kind of motor was quite difficult to develope. Because his employer Westinghouse desired a motor to run on just one phase.
29.04.2019 Rotor.
Observing the rotor in the patent it is a disk with cutaway corners. Long and narrow rectangle with rounded ends so it matches a circle circumference. The first rotor sheet was about 9.5 cm in diameter, and worked. for the disks cut out part, I usually cut away Radius / 2 from the diameter on each side of the central Origo point. If the disk has 9.5 cm in diameter, I cut away 9.5 cm Diameter / 4 = 2.3 cm on each side. I have made several rotor sheets of steel at 10 cm diameter. and also worked. Then I made some sheets being 5 cm in diameter, and I havent got that to rotate with these cores at all. Inspect the Patent drawing I see, the iron being left from the cutout, matches the donut hole of the coil or coil core size pretty decently. So having a coil donut of 4.2 cm the total diameter should be 8.4 cm, and 2.1 cm cut from each side. Presumably, as a starting point . when it comes to the wheight of the rotor and the number of plates the coils can rotate, I have got some results, but the sheets soon get heavy and slows down the speed. Each rotor blade is insulated with a brown packing paper. And I have a feeling that its equally important to insulate the plates as it is by insulating each turn on a coil. (!)
Regarding the diameter of the rotor compared to the diameter of the coils, or the wheight of the rotor . However som more testing and investigating that double coil alittle closer. I see that when comparing the 2 double coils, all coils have 15.5 ohms. but 2 coils have anddtional wire in a coil also of 15.5 ohm. these are short circuited, as a closed circuit . And this adds to the tork tremdously. and additional effects is that probably the cosinus phi is lowered on these coils so when the secondarys on the double coils are closed, no iron cores is needed at all. and also the cores can have very close distance to the rotor. that is to have short circuited secondarys on 2 of the coils, having the same ohm as the other coils. Ohn very rare occations you strick luck and I think I just did. Now I have also all 4 coils out of single wire coils and its more difficult to get a rotation but it works.with these particular iron cores, about 45 cm long. I get a no rotation or similar phase between the coils at 0 - 4cm and a 180 degree phase delay at about 30 cm when displacing the magnetic dealy coils. I presume the 90 degree off phase is about 13 cm from the core . and that works.
30.04.2017
Translating a circular circumference into a Rectangular circumference.
Sometimes it is neccesarry to have squar shaped coils and not round. This is a method I am going to use. First I have a circular circumference that I use, in this case core Diameter = 4.2 cm
D diameter Coil = 4.2 cm
Define the circular circumference, that is 1 turn of wire .
O = Pi * D = 3.14 * 4.2 cm = 13.19 cm circumference , lenght of 1 turn of copper wire.
Find the equivalent lenght around a square .
O circumference / 4 = 13.19 / 4 = 3.29 cm on all 4 sides of the square
Then presume the size of the rotor that is to be magnetized, in this case it is 4.2 cm that matches the coil diameter donut hole.
Recangle coil short side = 4.2 cm
Rectangle coil long side = (O circumference - (shortside * 2)) / 2 = (13.19 - 4.2*2) /2 = 4.76 / 2 = 2.39 cm
Here the longsides and shortsides needs to be flipped. However the rectangle conserves the same ohm per turn on the coil.
Check Rectangle = 2.39 + 2.39 + 4.2 + 4.2 = 13.19 cm circumference for the copper wire. The ohm is conserved but the geometry is changed.
Obtain the diameter from a circumference :
O circumference / pi = 13.19 / 3.14 = 4.2 cm diameter if a circle .
08.05.2017
I have got myself a new Multimeter that I trust, and it measure the circuit Resistance at about 65 ohm. The current in the motor coils is starting at 0.95A, then the coils get hot, and after about 40 minutes the Ampere is down to 0.82A. I figure 950mA - 820mA = 130mA is lost into heat. And I dont want a heater, I dont want IR radiation or hot coils, I want a large magnetic field, with cold or room temperate coils. So I want to translate the loss of heat into a magnetic field. I construct new coils that have a sligtly larger Resistance, by having more turns of the same wire gauge, then lowering the temprature of the coils, by increasing the Ampere Turns. I also found a method of making the rotor self start ! And I get a rotation of a rotor wheighing about 365 gram, thats an improvement from the first run, when the rotor wheighed about 25 gram, using the same coils showed in the video feed . Rotating at decent speed, but not top speed. I would recommend anybody interested in Magnetic action to read the patent, and try to make it work. It is very amusing .
Making it about 230V * 0.82A = 190VA motor
P = R * I^2 = 65 ohm * 0.82^2A = 43.7 watt
S = U * I = 230V * 0.82A = 188.6 VA
cos phi = P / S = 43.7 / 188.6 = 0.23 ! ( a very low cosine. commercial motors are about 0.95 !)
SAFETY : Under no circumstance touch the coils,wires or iron cores during operation. The amperes and frequency is dangerous, and may cause heart fibrillations. If shocked contact the doctor, its usually a 12 - 24 hours medical check after a stun. Turn the motor off when adjusting the magnets. And I pull out the plug when wiring the wires, just to be safe.
The work on the motor started about a year ago, and before that also some failed attempts. The first mistake I did was to have too thin wire, and too small a magnetic field for the rotor. I understood I had to design a series of coils that first of all did not burn up at mains 50 hertz, 230V AC pressure, meaning the Ohm was too low and the Ampere too high, but also producing a strong enough magnetic field to grab onto the iron disk rotor. From experience I know that about 40-60 ohm is sufficient using a AWG 24 wire ( 0.5 mm diameter crossection ) . So I coiled up 4 coils of 60 ohm / 4 coils = 15 ohm . the coils used is actually 15.5 ohms however and wired in series, basically 1158 turns, AWG24 Ø = 0.511 mm wire diameter. Coil chassy is a steel pipe about 42 mm diameter and 40 mm long between the faces.
Tesla decribes in the patent that using long iron cores will produce a phase differance in relation to a short iron core with a coil. To make the motor function it has to be understood how the coils are ordered, this is not desribed clearly in the patent, but if one pair of coils that are diameterically opposed, share the magnetic field like one bar magnet that is split on the middle. and so are the pair on 90 degrees. It is of great importance to wind the coils in the same manner, that is to be certain where the IN wire enters, and where the OUT wire exits, and wind all the coils either from top left to right bottom or vice versa, to keep track of the magnetic fields when placing the electromagnets .
Measured with DC current the fields should be like this.
N
S
N S . N S
N
S
This is a AC motor so the poles will shift. The next problem is to balancing the magnetic field strenght onto the rotor, in relation to the phase differance between the coils. I tried many things but after a while I removed the long core coils completely and did a magnetic test using just the short core coils. Then moving the short core pair as far away from the rotor as it barely managed to attract or magnetize a quarter swing the rotor to a fixed position when the current was turned on. Then I positioned back the long core coils, but with these I placed the irons very close to the rotor, so the rotor would get a strong magnetic field, however at a delay. I gradually moved the long core coils away from the rotor, I tried 3 cm distance from the rotor, 4 cmall the way to about 11 cm distance on these particular coils the rotor gave a motion of rotation . I was amazed . However the first times the rotor stopped after a short while , doing only some few turns . I was so close, but why did it stop ? I took some hours to think of it. contemplating a new rotor with a bearing. I then inspected the central hole of the iron rotor disk and found out that the hole I drilled had some irregular corners. the rotor shaft is a lso a threaded pin, and the disk edges into the thread and that also prohibits rotation. I filed it the rotor hole decently round. and there it was ! Spinning like a happy dancer . I am very happy that I made it work. An induction motor made from scratch .
I also have developed a computer program to calculate the coils. That is somewhat uselful. However theory is not the complete answer to such devices. There is a ton of theory online and in conventional electrical books. All shcematics seems to copy one another . There is very difficult to convert a mathematical result into a material construction, especially concerning energy and fields. for instance a coil with B = 0.5 tesla, what are the coil dimensions, the amperes, the reactance ?
I also have developed a computer program to calculate the coils. That is somewhat uselful. However theory is not the complete answer to such devices. There is a ton of theory online and in conventional electrical books. All shcematics seems to copy one another . There is very difficult to convert a mathematical result into a material construction, especially concerning energy and fields. for instance a coil with B = 0.5 tesla, what are the coil dimensions, the amperes, the reactance ?
Here is a video of the Motor :
The long core coils was changed after the first initial failed tests, I wound them out of the coil chassy, saved the wire and reused it on a new coil chassys, that was longer and could hold more turns. I figured the magnetic field was too low. and I made a longer chassy, and added another coil in parallell ontop of the first. the initial turns was 1158 turns, but I then had to make a choise, shall I wire the next coil with another 1158 turns or should I constrain myself to 15.5 ohm. since its a parallell wiring, I went for constrining the ohm, so the coil ontop of the other didnt have 1158 turns and maybe 30 ohm. the ohm increases because the increased diameter. So the outer parallell coil has about 640 turns.This works as seen on the video, but not essential. What I later realized is that I had been sent a wire that was maybe AWG25 or 26. being 1 thenth of a millimeter thinner. increasing the resistance drastically, with excellent service from the wire provider, I got a refund wire of proper diameter and labelling. It is worth mentioning that the Resistance is one thing, but in an AC coil its actually the effective resistance ( or Real resistance ) in Impedance that is the important factor, and the Impedance is always larger than the resistance. Just like the Hypothenus is always longer than the kateths of a triangle .
Previously I wrote 1240 turns but is an error due to the fact that I uncoiled the origional wire chassy of 1158 turns onto a coil chassy with a longer core, then there was less layers and got more turns with the same lenght of wire.
11.04.2017
I disconnected the paralllell windings on the long core coils and only used the 1158 turns of wire on all 4 coils. And I replaced the short core irons cores with wood cylinders. I then managed to move the short cores much closer to the rotor, and also have the long cores and its belonging coils very close to the rotor.
The speed of the rotor is very low, and the tork is also poor, but this may be that is only one thin steel disk of rotor. I will add more layers of sheet iron and a bearing to the rotor to check if it speeds up and gives a more decent tork.
Nikola Tesla himself says in his notes somewhere that this kind of motor was quite difficult to develope. Because his employer Westinghouse desired a motor to run on just one phase.
29.04.2019 Rotor.
Observing the rotor in the patent it is a disk with cutaway corners. Long and narrow rectangle with rounded ends so it matches a circle circumference. The first rotor sheet was about 9.5 cm in diameter, and worked. for the disks cut out part, I usually cut away Radius / 2 from the diameter on each side of the central Origo point. If the disk has 9.5 cm in diameter, I cut away 9.5 cm Diameter / 4 = 2.3 cm on each side. I have made several rotor sheets of steel at 10 cm diameter. and also worked. Then I made some sheets being 5 cm in diameter, and I havent got that to rotate with these cores at all. Inspect the Patent drawing I see, the iron being left from the cutout, matches the donut hole of the coil or coil core size pretty decently. So having a coil donut of 4.2 cm the total diameter should be 8.4 cm, and 2.1 cm cut from each side. Presumably, as a starting point . when it comes to the wheight of the rotor and the number of plates the coils can rotate, I have got some results, but the sheets soon get heavy and slows down the speed. Each rotor blade is insulated with a brown packing paper. And I have a feeling that its equally important to insulate the plates as it is by insulating each turn on a coil. (!)
Regarding the diameter of the rotor compared to the diameter of the coils, or the wheight of the rotor . However som more testing and investigating that double coil alittle closer. I see that when comparing the 2 double coils, all coils have 15.5 ohms. but 2 coils have anddtional wire in a coil also of 15.5 ohm. these are short circuited, as a closed circuit . And this adds to the tork tremdously. and additional effects is that probably the cosinus phi is lowered on these coils so when the secondarys on the double coils are closed, no iron cores is needed at all. and also the cores can have very close distance to the rotor. that is to have short circuited secondarys on 2 of the coils, having the same ohm as the other coils. Ohn very rare occations you strick luck and I think I just did. Now I have also all 4 coils out of single wire coils and its more difficult to get a rotation but it works.with these particular iron cores, about 45 cm long. I get a no rotation or similar phase between the coils at 0 - 4cm and a 180 degree phase delay at about 30 cm when displacing the magnetic dealy coils. I presume the 90 degree off phase is about 13 cm from the core . and that works.
30.04.2017
Translating a circular circumference into a Rectangular circumference.
Sometimes it is neccesarry to have squar shaped coils and not round. This is a method I am going to use. First I have a circular circumference that I use, in this case core Diameter = 4.2 cm
D diameter Coil = 4.2 cm
Define the circular circumference, that is 1 turn of wire .
O = Pi * D = 3.14 * 4.2 cm = 13.19 cm circumference , lenght of 1 turn of copper wire.
Find the equivalent lenght around a square .
O circumference / 4 = 13.19 / 4 = 3.29 cm on all 4 sides of the square
Then presume the size of the rotor that is to be magnetized, in this case it is 4.2 cm that matches the coil diameter donut hole.
Recangle coil short side = 4.2 cm
Rectangle coil long side = (O circumference - (shortside * 2)) / 2 = (13.19 - 4.2*2) /2 = 4.76 / 2 = 2.39 cm
Here the longsides and shortsides needs to be flipped. However the rectangle conserves the same ohm per turn on the coil.
Check Rectangle = 2.39 + 2.39 + 4.2 + 4.2 = 13.19 cm circumference for the copper wire. The ohm is conserved but the geometry is changed.
Obtain the diameter from a circumference :
O circumference / pi = 13.19 / 3.14 = 4.2 cm diameter if a circle .
08.05.2017
I have got myself a new Multimeter that I trust, and it measure the circuit Resistance at about 65 ohm. The current in the motor coils is starting at 0.95A, then the coils get hot, and after about 40 minutes the Ampere is down to 0.82A. I figure 950mA - 820mA = 130mA is lost into heat. And I dont want a heater, I dont want IR radiation or hot coils, I want a large magnetic field, with cold or room temperate coils. So I want to translate the loss of heat into a magnetic field. I construct new coils that have a sligtly larger Resistance, by having more turns of the same wire gauge, then lowering the temprature of the coils, by increasing the Ampere Turns. I also found a method of making the rotor self start ! And I get a rotation of a rotor wheighing about 365 gram, thats an improvement from the first run, when the rotor wheighed about 25 gram, using the same coils showed in the video feed . Rotating at decent speed, but not top speed. I would recommend anybody interested in Magnetic action to read the patent, and try to make it work. It is very amusing .
Making it about 230V * 0.82A = 190VA motor
P = R * I^2 = 65 ohm * 0.82^2A = 43.7 watt
S = U * I = 230V * 0.82A = 188.6 VA
cos phi = P / S = 43.7 / 188.6 = 0.23 ! ( a very low cosine. commercial motors are about 0.95 !)
SAFETY : Under no circumstance touch the coils,wires or iron cores during operation. The amperes and frequency is dangerous, and may cause heart fibrillations. If shocked contact the doctor, its usually a 12 - 24 hours medical check after a stun. Turn the motor off when adjusting the magnets. And I pull out the plug when wiring the wires, just to be safe.
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