Hi all.
Yesterday I started to read Tesla's patents (thanks slayer007) especially those about one wire/wireless enegry transmission.This is very interesting stuff to read, but still, there are some things that I don't understand entirely So lets start with the one wire transmission patent (593,138).
Tesla used a one layer pancake coil as the secondary of the transmitter and as the primary of the reciever. He used the pancake coil because of its geometry. A coil wound in such manner has high inductance and low resistance. Such a coil can develop very high voltages on the center wire end. Tesla stated that he could make the secondary voltage up to 1000 times greater than the primary voltage. The primary should be wound using a wire of certain length depending on the oscillation frequency that you will be using. He suggests that the wire length should be 1/4 of the wavelength. That means that if eceltricity flows through a wire at the speed of light, that is about 300 000 kilometers per second and you want to use an oscillation frequency of 300KHz, the wavelength will be 1km thus 250m of wire should be used for both the recieving and transmitting pancake coils. Tesla statet that you can use a core in the center of the pancake coil if you want. The primary coil of the transmitter has only few turns of heavier gauge wire wound around the outer perimeter of the pancake coil. The low tension wire end of the pancake coil is connected to the primary coil and then grounded, this is only for safety reasons. The reciever coils are exactly the same in proportions and wire lengths. But here instead the primary coil is the pancake coil and the secondary coil is the low voltage coil. And you can attach the load to the low voltage secondary coil. Also here the primary and secondary coils are grounded. Tesla does not talk much about the power source of the transmitter, it is just said, that it operates at high frequency and high voltage, probably just enough for a spark to jump across the spark gap. He said that he charged up a capacitor and then just discharged it into the primary coil on each impulse. There are also nothing said about the primary and secondary coil ratio. We know that the secondary should be wound from a wire that is 1/4 wavelength, but nothing is said about the turn count of the primary. Why? Is ist not important? Or should it only be mass matched?
Anyway, now to the next patent (645,576):
In this patent Tesla says, that if natural mediums, such as air, is subjected to disturbances of high potential and high frequency, the medium becomes a conductor and you can use that to transmit energy through it. This time there are no wires, the basic setup is the same, but now there is a capacity attached to the high tension wire of the secondary of the transmitter. Telsa states that the capacity, preferably in a spherical form, should be elevated in air as much as possible for best results. Also the reciever coils are the mirror image of the transmitter coils. And the heavy gauge coils are not grounded. The high frequency high voltage oscillations excite the air around the elevated capacity and this makes some stratas or chanells of rarified (or ionized?) air to appear through which electricity can flow at great distances almost without any losses.
There are much more info in the patent and I encourage everyone to read it.
So I guess that if you want to experiment with these things, you will need a variable high voltage capacitor, a high voltage power supply and of course the coils. One could simply use a neon sign HV power supply as the power source, but the problem is its frequency, because they usually operate at 50/60Hz, that means that the the coil wire length should be 1/4 of the wavelength, then at 50Hz you would need 1500km of wire Obviously that is not very practical. The higher the frequency the shorter wire is needed for the secondary coil. So I guess that 200-300KHz could be a good operation frequency, but how to achieve this? I suppose that this could be achieved if the output of the NST is rectified and filtered with a high value cap. Then the power from this HV filter cap could charge up a smaller value HV cap through an inductor and blocking diode.
This is called resonant charging and you can read more about that here:
DC Tesla Coil design
This way we can charge up the smaller capacity cap to a breakdown voltage that is required for the spark to jump across the spark gap. The spark will jump the gap and discharge the cap and then the cap starts to charge up again. So the discharge frequency here would be limited only by the cap value. And you would be able to adjust the discharge frequency by varying the spark gap length and capacitor capacity. Here's where the variable HV cap becomes useful. Could this work? What else could you suggest for a person who wants to play around with these things? I thought that maybe some magnets for quenching the spark would be advisable or submersing the spark in oil to achieve better results. Any ideas? suggestions?
Thank you
Yesterday I started to read Tesla's patents (thanks slayer007) especially those about one wire/wireless enegry transmission.This is very interesting stuff to read, but still, there are some things that I don't understand entirely So lets start with the one wire transmission patent (593,138).
Tesla used a one layer pancake coil as the secondary of the transmitter and as the primary of the reciever. He used the pancake coil because of its geometry. A coil wound in such manner has high inductance and low resistance. Such a coil can develop very high voltages on the center wire end. Tesla stated that he could make the secondary voltage up to 1000 times greater than the primary voltage. The primary should be wound using a wire of certain length depending on the oscillation frequency that you will be using. He suggests that the wire length should be 1/4 of the wavelength. That means that if eceltricity flows through a wire at the speed of light, that is about 300 000 kilometers per second and you want to use an oscillation frequency of 300KHz, the wavelength will be 1km thus 250m of wire should be used for both the recieving and transmitting pancake coils. Tesla statet that you can use a core in the center of the pancake coil if you want. The primary coil of the transmitter has only few turns of heavier gauge wire wound around the outer perimeter of the pancake coil. The low tension wire end of the pancake coil is connected to the primary coil and then grounded, this is only for safety reasons. The reciever coils are exactly the same in proportions and wire lengths. But here instead the primary coil is the pancake coil and the secondary coil is the low voltage coil. And you can attach the load to the low voltage secondary coil. Also here the primary and secondary coils are grounded. Tesla does not talk much about the power source of the transmitter, it is just said, that it operates at high frequency and high voltage, probably just enough for a spark to jump across the spark gap. He said that he charged up a capacitor and then just discharged it into the primary coil on each impulse. There are also nothing said about the primary and secondary coil ratio. We know that the secondary should be wound from a wire that is 1/4 wavelength, but nothing is said about the turn count of the primary. Why? Is ist not important? Or should it only be mass matched?
Anyway, now to the next patent (645,576):
In this patent Tesla says, that if natural mediums, such as air, is subjected to disturbances of high potential and high frequency, the medium becomes a conductor and you can use that to transmit energy through it. This time there are no wires, the basic setup is the same, but now there is a capacity attached to the high tension wire of the secondary of the transmitter. Telsa states that the capacity, preferably in a spherical form, should be elevated in air as much as possible for best results. Also the reciever coils are the mirror image of the transmitter coils. And the heavy gauge coils are not grounded. The high frequency high voltage oscillations excite the air around the elevated capacity and this makes some stratas or chanells of rarified (or ionized?) air to appear through which electricity can flow at great distances almost without any losses.
There are much more info in the patent and I encourage everyone to read it.
So I guess that if you want to experiment with these things, you will need a variable high voltage capacitor, a high voltage power supply and of course the coils. One could simply use a neon sign HV power supply as the power source, but the problem is its frequency, because they usually operate at 50/60Hz, that means that the the coil wire length should be 1/4 of the wavelength, then at 50Hz you would need 1500km of wire Obviously that is not very practical. The higher the frequency the shorter wire is needed for the secondary coil. So I guess that 200-300KHz could be a good operation frequency, but how to achieve this? I suppose that this could be achieved if the output of the NST is rectified and filtered with a high value cap. Then the power from this HV filter cap could charge up a smaller value HV cap through an inductor and blocking diode.
This is called resonant charging and you can read more about that here:
DC Tesla Coil design
This way we can charge up the smaller capacity cap to a breakdown voltage that is required for the spark to jump across the spark gap. The spark will jump the gap and discharge the cap and then the cap starts to charge up again. So the discharge frequency here would be limited only by the cap value. And you would be able to adjust the discharge frequency by varying the spark gap length and capacitor capacity. Here's where the variable HV cap becomes useful. Could this work? What else could you suggest for a person who wants to play around with these things? I thought that maybe some magnets for quenching the spark would be advisable or submersing the spark in oil to achieve better results. Any ideas? suggestions?
Thank you
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