How can I find a frequency of Infraheat infrared that emit from the sun or else? I see in Wikipedia that infraheat wavelengths are from 300 GHz to 430 THz. My idea is to find resonance and use like a shield. Is there a way to do that?
So the current is ackumulated in the coilsmagnetic field and since it has nowwhere to go it gets pushed back into the oscillator. At the frequency where the coil is ackumulating the most it generate most kickback and thus the leds are brighter? Edit i see now, you connected the the oscilloscope to the multimeter.
Not in this setup. I’m driving the coil from a tube oscillator at low amplitude just to look for resonance. There is no real power coming from the coil.
Same with a 1/2 wave dipole radio antenna. One side of the antenna is connected to the transmitter output. What is the other end of the antenna hooked to? Nothing, seemingly. Because, you're right, we're all taught "there needs to a circuit for current to flow" to power loads like LEDs etc. Okay, so how come one end of a transmitter's antenna is not connected to anything? IT'S CONNECTED *_capacitively_* TO GROUND. The space gap between the 'open' end of the antenna and earth ground is a capacitance. In this demo, you saw that the top of the coil is electrically 'floating', seemingly not part of a circuit. But it is connected, by way of the same manner of capacitance, as a radio transmitter's antenna. If the space gap between the top 'floating' end of that large inductor was moved closer (or further away) from ground, it would change the capacitance. And if the capacitance changed, so would the resonant frequency. The TOTAL capacitance of that large coil consists of: 1) the between-winding capacitance up and down through the coil windings; each adjacent set of windings forms a capacitor 2) add up all those 'between-winding' capacitances to the space gap between ground and the 'floating' topmost wire of the coil The formula for resonance frequency is: Fr = 1 / sqrt(2pi LC) where pi = 3.14159... L = the inductance of the coil C = the total capacitances (described above) The 'gotcha' in electrical engineering courses is, we're taught in the very 1st course "you must have a circuit for current to flow to power loads" and in a much later course we learn about antennas, which do NOT have a discrete capacitor that can be seen - yet the AC or RF current still flows in the antenna. "Why didn't they teach that from the beginning" it's a reasonable question. "Later in the curriculum, we're going to seemingly break the rule that 'you must have a circuit' by relying on an invisible capacitor to allow an AC or RF current flow despite the circuit appearing to be open." . .
@@Greg_Chase EVERYONE interested enough to be here should read an internalize these wise words! This is an extremely clear and concise explanation of what is happening. Bravo!
Harold Victor It is an old vacuum tube oscillator that outputs a variable frequency sign wave. You can use a function generator set to output a sign wave. I got this one off eBay.
Bill Kordis The output of the oscillator is a sign wave and is hooked to the base of the coil through a 1K resistor. The scope probe just needs to be in close proximity of the coil to pick up the resonant frequency. While sweeping the frequency range you will see several harmonic peak frequencies, you want the one with the highest amplitude. Hope that helps!
@@Tesla210 He is suggesting that the attachment of the various test meters places a burden on the DUT which influences reading its true characteristics. A similar effect is seen when attaching a scope to an oscillator... The capacitance of the scope probe can influence the oscillator, even to the point of shutting it down. This can give a false test reading, showing that the oscillator is bad, when actually it is good. HTH.
@@t1d100 In this setup the scope probe isn’t physically connected but rather hanging in the vicinity. My multimeter is hooked up in the video to read the frequency but had little affect on the resonance of the coil
Hepful video, thanks.
Nice Demo!
Oh wow thats nice man!
Super excellent. Thank you.
I was worried it could make a project of mine really complicated... couldnt be easier, thanks!
Cool! Thanks!
Awesome
How can I find a frequency of Infraheat infrared that emit from the sun or else? I see in Wikipedia that infraheat wavelengths are from 300 GHz to 430 THz. My idea is to find resonance and use like a shield. Is there a way to do that?
So the current is ackumulated in the coilsmagnetic field and since it has nowwhere to go it gets pushed back into the oscillator. At the frequency where the coil is ackumulating the most it generate most kickback and thus the leds are brighter?
Edit i see now, you connected the the oscilloscope to the multimeter.
Is there any possibility that the coil could create some sort of a kickback that would harm your test gear? If so, how would you protect your gear?
Not in this setup. I’m driving the coil from a tube oscillator at low amplitude just to look for resonance. There is no real power coming from the coil.
Would you please explain to me how the LEDs are lighting when the circuit is not complete as the other end of the coil is unattached? Thanks.
High voltage.
Same with a 1/2 wave dipole radio antenna. One side of the antenna is connected to the transmitter output. What is the other end of the antenna hooked to? Nothing, seemingly.
Because, you're right, we're all taught "there needs to a circuit for current to flow" to power loads like LEDs etc.
Okay, so how come one end of a transmitter's antenna is not connected to anything?
IT'S CONNECTED *_capacitively_* TO GROUND. The space gap between the 'open' end of the antenna and earth ground is a capacitance.
In this demo, you saw that the top of the coil is electrically 'floating', seemingly not part of a circuit. But it is connected, by way of the same manner of capacitance, as a radio transmitter's antenna.
If the space gap between the top 'floating' end of that large inductor was moved closer (or further away) from ground, it would change the capacitance.
And if the capacitance changed, so would the resonant frequency.
The TOTAL capacitance of that large coil consists of:
1) the between-winding capacitance up and down through the coil windings; each adjacent set of windings forms a capacitor
2) add up all those 'between-winding' capacitances to the space gap between ground and the 'floating' topmost wire of the coil
The formula for resonance frequency is:
Fr = 1 / sqrt(2pi LC)
where pi = 3.14159...
L = the inductance of the coil
C = the total capacitances (described above)
The 'gotcha' in electrical engineering courses is, we're taught in the very 1st course "you must have a circuit for current to flow to power loads" and in a much later course we learn about antennas, which do NOT have a discrete capacitor that can be seen - yet the AC or RF current still flows in the antenna.
"Why didn't they teach that from the beginning" it's a reasonable question. "Later in the curriculum, we're going to seemingly break the rule that 'you must have a circuit' by relying on an invisible capacitor to allow an AC or RF current flow despite the circuit appearing to be open."
.
.
@@Greg_Chase EVERYONE interested enough to be here should read an internalize these wise words! This is an extremely clear and concise explanation of what is happening. Bravo!
How to tune a coil for given frequency? With same frequency can we make coil by different diameter and turns?
Nanni Galaxy Yes the coils diameter, wire size and length can be reconfigured to change the frequency.
@@Tesla210 does the magnetic field created depends on the wiresize, length and diameter of the coil?
Oluwatola Tofade Yes
hp-200CD what is that ?
can we make one or buy ?
Harold Victor It is an old vacuum tube oscillator that outputs a variable frequency sign wave. You can use a function generator set to output a sign wave. I got this one off eBay.
is the scope hooked up to the top load wire connection
Bill Kordis No it is hanging just above the coil picking up the RF like an antenna.
@@Tesla210 can you tell me what the resistor value is, and how your wave generator is set up
Bill Kordis The output of the oscillator is a sign wave and is hooked to the base of the coil through a 1K resistor. The scope probe just needs to be in close proximity of the coil to pick up the resonant frequency. While sweeping the frequency range you will see several harmonic peak frequencies, you want the one with the highest amplitude. Hope that helps!
probes become part of the resonance. Resonance without probes and function gens?
Donald Haas I’m not sure I understand what you mean?
@@Tesla210 He is suggesting that the attachment of the various test meters places a burden on the DUT which influences reading its true characteristics. A similar effect is seen when attaching a scope to an oscillator... The capacitance of the scope probe can influence the oscillator, even to the point of shutting it down. This can give a false test reading, showing that the oscillator is bad, when actually it is good. HTH.
@@t1d100 In this setup the scope probe isn’t physically connected but rather hanging in the vicinity. My multimeter is hooked up in the video to read the frequency but had little affect on the resonance of the coil
I was unable to understand what you were doing. You seemed to be mumbling to yourself. A clearer explanation would be helpful.
Seems like a you problem. Find another video then.
@@Tesla210 woah man, i understand he was rude but dont get on his level, its his fault he can't understand basic English