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 Post subject: Questions Before Starting Out
PostPosted: Wed Jun 20, 2012 6:51 am 
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Hello, I'd like some clarifications about building a Bedini Fan. Forgive me if these are "stupid" questions as it's been years since I've taken electronics in high school. I can sorta read a schematic, but electronic fundamentals are fuzzy in my mind.

Referring to http://d1190995.domaincentral.com.au/Ch ... mfinal.pdf:

1. When cutting the copper wire at post number 1 in the top coil diagram to separate the drive and pick-up coils (wrapped clockwise and counter-clockwise respectively, or vice-versa), the diagram sort of implies that the coils that are wrapped the same direction are beside each other (i.e. 90 degrees away in a 360-degree circle). Or are computer fans typically wound so that the clockwise coils are 180 degrees apart, and each counter-clockwise coil is 180 degrees apart? The schematic on page 2 seems to imply this.

2. Would I have to worry about burning something out (such as kill the transistor) if I somehow don't get the coils hooked up to the circuit properly, or I spin the fan the wrong way?

3. I have several fans. They're all 12V. The smallest is .21A and the largest is 2.5A. Should I be concerned about the size (i.e. wattage) potentiometer would I need to handle the 2.5A fan without heating up and/or burning it out? I haven't taken it completely apart yet, but I like it as the copper wire on it is around the thickness of dental floss, and not paper thin like on the the smaller fans. A link to Mouser or DigiKey would be helpful.

4. Rather than having a battery to run the fan and a battery to charge, can I get away with just a capacitor to run the fan, or heck: no capacitor at all? I'd like to demonstrate the fan to friends/co-workers what is possible, and I don't want them to say, "Hey, it's just being run off a battery!" If I do need a capacitor, what rating would I need?


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 Post subject: Re: Questions Before Starting Out
PostPosted: Wed Jun 20, 2012 1:48 pm 
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GaryP wrote:
Hello, I'd like some clarifications about building a Bedini Fan. Forgive me if these are "stupid" questions as it's been years since I've taken electronics in high school. I can sorta read a schematic, but electronic fundamentals are fuzzy in my mind.

Referring to http://d1190995.domaincentral.com.au/Ch ... mfinal.pdf:

1. When cutting the copper wire at post number 1 in the top coil diagram to separate the drive and pick-up coils (wrapped clockwise and counter-clockwise respectively, or vice-versa), the diagram sort of implies that the coils that are wrapped the same direction are beside each other (i.e. 90 degrees away in a 360-degree circle). Or are computer fans typically wound so that the clockwise coils are 180 degrees apart, and each counter-clockwise coil is 180 degrees apart? The schematic on page 2 seems to imply this.


The wires are wound at the same time beside each other so they are identical in their direction and phase but they are wound clockwise on the first post and anticlockwise on the next and so on.

GaryP wrote:
2. Would I have to worry about burning something out (such as kill the transistor) if I somehow don't get the coils hooked up to the circuit properly, or I spin the fan the wrong way?


No, the only risk is from the spike when it is wired correctly, that's why we have neons to absorb the spike when no charging battery is connected. With the big fan, don't run it without a charging battery or you may blow the neon and the transistor.

GaryP wrote:
3. I have several fans. They're all 12V. The smallest is .21A and the largest is 2.5A. Should I be concerned about the size (i.e. wattage) potentiometer would I need to handle the 2.5A fan without heating up and/or burning it out? I haven't taken it completely apart yet, but I like it as the copper wire on it is around the thickness of dental floss, and not paper thin like on the the smaller fans. A link to Mouser or DigiKey would be helpful.


The small fan will probably draw about 50 to 80ma average when wired this way and will probably burn out a carbon film pot like a volume control. I use a 5w wire wound pot of 500 ohms. Your big fan may burn out this pot too if your not careful, I put a resistor in parallel to mine when when running my SSG with the bike wheel (its the same circuit). I tune the pot to find the resistance then put a 5w resistor of double the resistance in parallel so that only half the power is going through the pot.

GaryP wrote:
4. Rather than having a battery to run the fan and a battery to charge, can I get away with just a capacitor to run the fan, or heck: no capacitor at all? I'd like to demonstrate the fan to friends/co-workers what is possible, and I don't want them to say, "Hey, it's just being run off a battery!" If I do need a capacitor, what rating would I need?


Not with this circuit, No one that I know has ever made this self running although some have made it closer to being self running. IT should be possible with a different circuit and I am working on that. It is possible to prove overunity with this circuit when it is tuned correctly when you add the mechanical power of the fan to the charge found in the charging battery. This is one of the reasons the fan is such a great learning tool.

I can't wait to hear about your big fan once you have it running
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 Post subject: Re: Questions Before Starting Out
PostPosted: Thu Jun 21, 2012 7:25 am 
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mbrownn wrote:
The wires are wound at the same time beside each other so they are identical in their direction and phase but they are wound clockwise on the first post and anticlockwise on the next and so on.


So, to clarify, if the rotor is divided into a 12, 3, 6, and 9 o'clock position, 12 and 6 would be wound one direction, and 3 and 9 would be the opposite?

mbrownn wrote:
GaryP wrote:
2. Would I have to worry about burning something out (such as kill the transistor) if I somehow don't get the coils hooked up to the circuit properly, or I spin the fan the wrong way?


No, the only risk is from the spike when it is wired correctly, that's why we have neons to absorb the spike when no charging battery is connected. With the big fan, don't run it without a charging battery or you may blow the neon and the transistor.


Or I could attach something like a 120V light bulb if using the big fan? I should mention that the fan isn't physically big although the amp rating is high... it's probably because it's a variable speed CPU fan, and if I'm not mistaken, when it used to be in a computer, the fan would spin extremely fast upon boot up and then slow down; it had 4 wires rather than the usual 2.

mbrownn wrote:
GaryP wrote:
4. Rather than having a battery to run the fan and a battery to charge, can I get away with just a capacitor to run the fan, or heck: no capacitor at all? I'd like to demonstrate the fan to friends/co-workers what is possible, and I don't want them to say, "Hey, it's just being run off a battery!" If I do need a capacitor, what rating would I need?


Not with this circuit, No one that I know has ever made this self running although some have made it closer to being self running. IT should be possible with a different circuit and I am working on that. It is possible to prove overunity with this circuit when it is tuned correctly when you add the mechanical power of the fan to the charge found in the charging battery. This is one of the reasons the fan is such a great learning tool.


What modifications are necessary for it to be self-running? A circuit or relay to swap the supply and charge batteries, let's say, every second?


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 Post subject: Re: Questions Before Starting Out
PostPosted: Thu Jun 21, 2012 10:33 am 
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GaryP wrote:

So, to clarify, if the rotor is divided into a 12, 3, 6, and 9 o'clock position, 12 and 6 would be wound one direction, and 3 and 9 would be the opposite?


Yes, this is the normal winding for a brush-less fan.


GaryP wrote:

Or I could attach something like a 120V light bulb if using the big fan? I should mention that the fan isn't physically big although the amp rating is high... it's probably because it's a variable speed CPU fan, and if I'm not mistaken, when it used to be in a computer, the fan would spin extremely fast upon boot up and then slow down; it had 4 wires rather than the usual 2.


No, the neon will not pass any current until a certain voltage is reached so it acts a little like a relief valve but small neons can only pass a small amount of power, I suppose you could put multiple neons in parallel.

I don't know about the fan you mention, maybe it is best to open it up and take a look inside.

GaryP wrote:
What modifications are necessary for it to be self-running? A circuit or relay to swap the supply and charge batteries, let's say, every second?


As I said, I do not know of a self running fan yet although I am sure it is possible.

Batteries are strange things, especially lead acid ones. They can be made to charge with remarkable levels of efficiency when pulsed and even demonstrate overunity when charged in some specific ways although there are some downsides to this. We take advantage of one of these methods with the fan. The fan itself is very inefficient and has high losses but the way the battery charges is demonstrating a form of overunity. The overunity is in the battery and not the fan. One thing these batteries don't like is to be charged and discharged at the same time which rapid battery swapping amounts to.

The fan isn't perfect but is capable of demonstrating overunity and is an excellent first step into understanding what electricity is and what is possible. It is not what is written in the electrical books, its far more.


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 Post subject: Re: Questions Before Starting Out
PostPosted: Tue Jun 26, 2012 2:23 pm 
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Does this fan achieve overunity?


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 Post subject: Re: Questions Before Starting Out
PostPosted: Wed Jun 27, 2012 11:13 am 
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yes, in a way. The fan itself does not but when tuned correctly and charging the right sort of battery at the right speed, the combined energy found in the charging battery and the mechanical output of the fan are more than the input.


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