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Been having fun with hall effect sensors. Have used a unipolar hall effect sensor to create a pulse motor similar to the Bedini sensor coil style. I am planning to look at this further in terms of where one might like a pulse to occur, pulse duration, magnet spacing, magnet strength and so forth.
I had another idea and quite bluntly it has turned out to be seemingly beyond me (i.e Electronics 406), that is to create a brushless DC motor using a hall effect sensor. Before going into the details of my attempt let me note that a Bedini SSG runs in both attraction and repulsion mode. This implies that the rectified inductive radiant spike is independent of the orientation that the electromagnet is charged in. This further implies that any "AC magnetic motor" where the coil collapses might allow one to gather an inductive spike. So I wanted to make a brushless motor, like the SSG but switching the coil from positive to negative.
I had great initial success with this. I used a bipolar (i.e turned on by say North and off by South) latching (stays on until it sees the opposite magnetic field) hall effect sensor. I hooked it to two single pole double throw relays. When the hall effect sensor was on power flowed to one coil orientation, when off, to the other. I was quite pleased with myself ... until I tried a few magnets on the perimeter and things got close to 1000 rpms. The relays couldn't switch fast enough. Okay, easy enough, just go with transistors, this is when it all fell apart. Well, I never seem to know what's going to go easy with electronics, though it was easy with relays, this after a multiday battle has kicked my rear.
So that is the question, how do you use transistors to switch from one polarity to the other on an electromagnet?
What I finally came up with was 4 transistors (I'll try and diagram it if necessary). Positive to an NPN, negative to a PNP, negative to an NPN positive to PNP. Finally I had no shorts in the circuit and when an NPN and PNP were triggered the power flowed one way, when the other NPN/PNP were triggered the power flowed the other way. The problem then was how do you take the binary signal from a hall effect sensor and trigger one set of PNP/NPN transistors and then the opposite signal for the other PNP/NPN set, all without creating a short. As noted, kicked my hieney.
I am new at electronics and may just be missing something but I am not a complete idiot, I think this is a genuinely difficult problem. I am not asking for any immediate response, just if you get bored and want to spend a few hours let me know what you come up with.
I may perhaps use two sensors which would clear up the problem, the problem then is if the two sensors are not aligned and sensing the same thing, they would short because one would turn on while the other didn't turn off. Still it might be an answer.
Another carrot for this question, what happens when one switches in a "nanosecond" between positive and negative polarity on an electromagnet? There should be some time when the coil is releasing its stored energy and the opposite current is energizing the electromagnet. What about the inductive spike, is it "snuffed" out as it were or does it not give a crap about the incoming opposite polarity current? What happens to the radiant spike in this situation??
So again the question is, if you are bored or energized, how do use transistors to switch polarity on an electromagnet and how would this hook up to a latching bipolar hall effect sensor?
I had another idea and quite bluntly it has turned out to be seemingly beyond me (i.e Electronics 406), that is to create a brushless DC motor using a hall effect sensor. Before going into the details of my attempt let me note that a Bedini SSG runs in both attraction and repulsion mode. This implies that the rectified inductive radiant spike is independent of the orientation that the electromagnet is charged in. This further implies that any "AC magnetic motor" where the coil collapses might allow one to gather an inductive spike. So I wanted to make a brushless motor, like the SSG but switching the coil from positive to negative.
I had great initial success with this. I used a bipolar (i.e turned on by say North and off by South) latching (stays on until it sees the opposite magnetic field) hall effect sensor. I hooked it to two single pole double throw relays. When the hall effect sensor was on power flowed to one coil orientation, when off, to the other. I was quite pleased with myself ... until I tried a few magnets on the perimeter and things got close to 1000 rpms. The relays couldn't switch fast enough. Okay, easy enough, just go with transistors, this is when it all fell apart. Well, I never seem to know what's going to go easy with electronics, though it was easy with relays, this after a multiday battle has kicked my rear.
So that is the question, how do you use transistors to switch from one polarity to the other on an electromagnet?
What I finally came up with was 4 transistors (I'll try and diagram it if necessary). Positive to an NPN, negative to a PNP, negative to an NPN positive to PNP. Finally I had no shorts in the circuit and when an NPN and PNP were triggered the power flowed one way, when the other NPN/PNP were triggered the power flowed the other way. The problem then was how do you take the binary signal from a hall effect sensor and trigger one set of PNP/NPN transistors and then the opposite signal for the other PNP/NPN set, all without creating a short. As noted, kicked my hieney.
I am new at electronics and may just be missing something but I am not a complete idiot, I think this is a genuinely difficult problem. I am not asking for any immediate response, just if you get bored and want to spend a few hours let me know what you come up with.
I may perhaps use two sensors which would clear up the problem, the problem then is if the two sensors are not aligned and sensing the same thing, they would short because one would turn on while the other didn't turn off. Still it might be an answer.
Another carrot for this question, what happens when one switches in a "nanosecond" between positive and negative polarity on an electromagnet? There should be some time when the coil is releasing its stored energy and the opposite current is energizing the electromagnet. What about the inductive spike, is it "snuffed" out as it were or does it not give a crap about the incoming opposite polarity current? What happens to the radiant spike in this situation??
So again the question is, if you are bored or energized, how do use transistors to switch polarity on an electromagnet and how would this hook up to a latching bipolar hall effect sensor?
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