You get a PARALLEL resonance (capacitor in parallel with inductance) that is evident as the MAXIMUM voltage, when the source is through a resistor. You capacitance in your described arrangement is the capacitance that tends to resonate with your coil. You could put (a small) capacitor either in parallel or in series with the coil (and resistor) to get much better measurement results. You could find a Minimum amplitude of current measured at the resistor in parallel configuration, or a maximum current (highest voltage at the resistor) if you use a Series configuration. If you know your capacitor value, you can get your coil inductance from the resonant frequency. In most bench oscilloscopes, you have an input capacitance somewhere above 10 to 20 pF, or in really old scopes something like 47 pF. With a “10 x” probe you have about 1/10 of that capacitance. If you try with two fixed capacitors, you can work out, what is the stray capacitance of your coil. But be careful about the skin effect of the wire, when you advance to MHz frequencies!
So you just have a simple series circuit from the signal generator through a resistor and the coil is just tapped off at on end of it to the circuit and the other end is open, like an antennae?
Some kind of diagram would be helpful. Also, you didn't show us how to determine the resonant frequency of the primary coil. You only offer the secondary, which is half the puzzle. I love the channel! Thank you!
If I am not mistaken, though he did not show it, is the same circuit without the open-ended coil under test connected, would not have resulted in the peak of the voltage on the scope at a certain frequency. I would like to see the same test again without the coil under test to verify it was the COIL that made the difference at that frequency.
Aren't you really measuring the resonance of the coil inductance with the total capacitance of the oscilloscope probe, signal generator, and coil? How does that help? Is the capacitance of the oscilloscope probe plus signal generator insignificant compared to the capacitance of the coil?
Again... conducting the same test without the coil under test, I mean the same scope, same probe, same placement of everything with the absence of the coil under test would verify the coil made the difference and negates external influences.
@@johnclayton2101Not really. What you are trying to test is an LCR circuit whose resonant frequency is 1/(2*pi*sqrt(LC)). Without the coil there would be no L other than a tiny parasitic L from the scope probe.
PAUL, why is the AC voltage dropping at Resonant Frequency? the impedance is the lowests at Resonant frequency so the AC voltage is lower because of why?
@@freedomer342 the coils impedance is at maximum resistance at the coils resonance frequency so the AC voltage is lowered decreased. Why does the coils impedance increase to maximum at resonance frequency?
@waynegram8907 I'm not sure what you mean by complex impedance. Impedance is measured in ohms so it's like variable resistance that can change due to certain qualities like capacidence (at least when it comes to tesla coils, air core), temperture, humidity, etc. Becuase Paul found the low point, it was where the Impedance of the coil was matching the resonant frequency of the coil, causing the impedance to "cancel" itself out. He describes this in the beginning of the video.
@@freedomer342 if the impedance of the coil is Matching the resonant frequency which cancelling it out, why is the AC voltage dropping lower? I would think the AC voltage would increase because there is NO impedance of the coil
a 555 timer is essentially a signal generator. depending on factors of you coil, you might need something that pulses higher than a 555 timer like a signal generator
Paul, I offer this feedback with the best of intentions and with all due respect, in the true hopes of helping you. For me, this tutorial only brought confusion. There was not a schematic (there should always be one, at the front of the video.) This made it hard to understand the setup. Your instructions seemed ad lib'd, which made them hard to follow. Without watching the video multiple times and trying to sort things out, I would not be able to preform the test on my bench. I know that your channel has had it struggles and I hope this feedback will help. Thank you for your efforts to share and teach. I recognize your graciousness and I appreciate you.
red lead of signal generator connected to a resistor, which is then connected to the coil. the black lead of the signal generator is connected to the ground. his probe is connected in between the resistor and the coil, the ground portion of his probe (alligator clamp) is also going to ground
@@freedomer342 Thank you for your gracious efforts to help me understand. Any particular value of resistor? I'm sorry, but I don't understand the ground connection... If I understood Paul correctly, one end of the coil is attached to the signal generator output and the other end is left floating. This is why a schematic (hand drawn is fine) is so vital to the audience's understanding. I throw no stones, but a drawing really, really helps. I am really grateful for your efforts to help. This is what builds community. Thank you.
@t1d100 just a known resistor value like 1k or 10k. Doesn't matter. Yes one end of the coil is left floating. On the signal generator, the negative portion of it, is going to earth ground or house ground. Positive side is going to a resistor, the other side of the resistor is going to one end of the coil. The other end of the coil is not connected to anything.
I been watching germanium diode radio circuit videos which all need a tank circuit. I think somehow this video of yours might be of use to troubleshoot these crystal radio circuits but I'm missing something.
I am allso amased ,i wounder if what you are seeing is a harmonic of the resonate frequence. i would of expecterd low k/c .but like you said RF blck magic.
G,day from Sydney Australia. You've got me thinking... 1. I like your hand oscilloscope and power supply. 2. The Tesla coil: why the varying frequency increment response to increase voltage. 3. I associate it with the windings of a transformer? 🌏🇦🇺
Let me know if I understand you correctly, because as you say, the coil is an open, the other end is not in the circuit. If I understand you correctly, you are saying that even though the coil has one wire open, it still has an effect on the circuit because it is a COIL (inductance) in an AC driven circuit. So, in a DC circuit, the coil will resist the flow of current through the coil when power is first applied, even though t other wire is not tied into the "Circuit".? Am I correct? I mean when you flip the switch and apply a voltage, instantaneously, this coil will take on a charge and an electromagnetic charge in response to this power being applied to it, (power might not be the correct word. Voltage maybe?). The fact it is there, even if un-terminated, does have an affect on the rest of the circuit. Is that thought correct? But we are talking resonance of a coil, so an AC signal. And as you progressively increase the frequency of your signal generator, You were looking for peak voltage to see at what frequency the coil ADDED to the output measured voltage level. That is resonance. Just like in a shower... if you hit a not as you sing up and down in a scale of notes, at some point the oscillations of the frequency of your voice will vibrate the walls of the shower and make you sound amazing! That is the resonate frequency of your shower enclosure. AND the same circuit, without your open-ended coil would respond..... how? Differently I suppose. So the coil had an affect and the point of the frequency you applied to the circuit with the open-ended coil IN the circuit tells you the resonant frequency of that coil? Am I correct in understanding your point? Because the open-ended coil in the circuit adds to the output signal Peak-to-peak value at the output, the open-ended coil must be resonating and adding to the voltage at a certain frequency. Is that correct?
That is amazing. I believe it and I can understand it. It makes sense to me and you showed it happening. Thank you, Paul! I learned something, yet again, from your channel!
And skin-effect of the diameter of the wire, correct? Because current in an AC circuit tends to flow on the outer surface of a wire's diameter, if I am not mistaken.
I am sorry pal but this is not the resonance that you are measuring....you are measuring the opposite which is the attenuation freq of the coil. And if I were you I would try VASTLY different coils and see if they all cop-out @4.7MHZ ~+-1-2% because that may just be a limmiting factor of your Signal Gen or a consequence of the SigGen. I like to image Reso as a gatway to a different place when all conditions are right ....there is a spike an opening as it were not a dip or close door.
You get a PARALLEL resonance (capacitor in parallel with inductance) that is evident as the MAXIMUM voltage, when the source is through a resistor. You capacitance in your described arrangement is the capacitance that tends to resonate with your coil. You could put (a small) capacitor either in parallel or in series with the coil (and resistor) to get much better measurement results. You could find a Minimum amplitude of current measured at the resistor in parallel configuration, or a maximum current (highest voltage at the resistor) if you use a Series configuration. If you know your capacitor value, you can get your coil inductance from the resonant frequency. In most bench oscilloscopes, you have an input capacitance somewhere above 10 to 20 pF, or in really old scopes something like 47 pF. With a “10 x” probe you have about 1/10 of that capacitance. If you try with two fixed capacitors, you can work out, what is the stray capacitance of your coil. But be careful about the skin effect of the wire, when you advance to MHz frequencies!
So you just have a simple series circuit from the signal generator through a resistor and the coil is just tapped off at on end of it to the circuit and the other end is open, like an antennae?
Some kind of diagram would be helpful. Also, you didn't show us how to determine the resonant frequency of the primary coil. You only offer the secondary, which is half the puzzle. I love the channel! Thank you!
If I am not mistaken, though he did not show it, is the same circuit without the open-ended coil under test connected, would not have resulted in the peak of the voltage on the scope at a certain frequency. I would like to see the same test again without the coil under test to verify it was the COIL that made the difference at that frequency.
Aren't you really measuring the resonance of the coil inductance with the total capacitance of the oscilloscope probe, signal generator, and coil? How does that help? Is the capacitance of the oscilloscope probe plus signal generator insignificant compared to the capacitance of the coil?
Again... conducting the same test without the coil under test, I mean the same scope, same probe, same placement of everything with the absence of the coil under test would verify the coil made the difference and negates external influences.
@@johnclayton2101Not really. What you are trying to test is an LCR circuit whose resonant frequency is 1/(2*pi*sqrt(LC)). Without the coil there would be no L other than a tiny parasitic L from the scope probe.
PAUL, why is the AC voltage dropping at Resonant Frequency? the impedance is the lowests at Resonant frequency so the AC voltage is lower because of why?
because the impedance of the coil and the resonant frequency are the same
@@freedomer342 the coils impedance is at maximum resistance at the coils resonance frequency so the AC voltage is lowered decreased. Why does the coils impedance increase to maximum at resonance frequency?
@@freedomer342 what is the difference between impedance VS compared to complex impedance? Of an inductor coil
@waynegram8907 I'm not sure what you mean by complex impedance. Impedance is measured in ohms so it's like variable resistance that can change due to certain qualities like capacidence (at least when it comes to tesla coils, air core), temperture, humidity, etc. Becuase Paul found the low point, it was where the Impedance of the coil was matching the resonant frequency of the coil, causing the impedance to "cancel" itself out. He describes this in the beginning of the video.
@@freedomer342 if the impedance of the coil is Matching the resonant frequency which cancelling it out, why is the AC voltage dropping lower? I would think the AC voltage would increase because there is NO impedance of the coil
What's the inductance values. There should be a calculation too. Prob involving 2xPi and Freq ...
can i use a 555 timer to generate the frequency? i dont have a oscilocope
a 555 timer is essentially a signal generator. depending on factors of you coil, you might need something that pulses higher than a 555 timer like a signal generator
Paul, I offer this feedback with the best of intentions and with all due respect, in the true hopes of helping you. For me, this tutorial only brought confusion. There was not a schematic (there should always be one, at the front of the video.) This made it hard to understand the setup. Your instructions seemed ad lib'd, which made them hard to follow. Without watching the video multiple times and trying to sort things out, I would not be able to preform the test on my bench. I know that your channel has had it struggles and I hope this feedback will help. Thank you for your efforts to share and teach. I recognize your graciousness and I appreciate you.
red lead of signal generator connected to a resistor, which is then connected to the coil. the black lead of the signal generator is connected to the ground. his probe is connected in between the resistor and the coil, the ground portion of his probe (alligator clamp) is also going to ground
@@freedomer342 Thank you for your gracious efforts to help me understand. Any particular value of resistor? I'm sorry, but I don't understand the ground connection... If I understood Paul correctly, one end of the coil is attached to the signal generator output and the other end is left floating. This is why a schematic (hand drawn is fine) is so vital to the audience's understanding. I throw no stones, but a drawing really, really helps. I am really grateful for your efforts to help. This is what builds community. Thank you.
@t1d100 just a known resistor value like 1k or 10k. Doesn't matter. Yes one end of the coil is left floating. On the signal generator, the negative portion of it, is going to earth ground or house ground. Positive side is going to a resistor, the other side of the resistor is going to one end of the coil. The other end of the coil is not connected to anything.
@@freedomer342 Ahh... Thank you for clearing that up. You are most kind. Cheers.
@@freedomer342 The other thing that I have realized is that, if your signal generator does not have much bandwidth, you may not find the deepest dip.
looking forward to the rest of this project cause i wanna make this.
I been watching germanium diode radio circuit videos which all need a tank circuit.
I think somehow this video of yours might be of use to troubleshoot these crystal radio circuits but I'm missing something.
If you do this with a strung guitar, would you be able to hear it resonating?
So, you roll your own? 😎
Cool mon.
☮️✌️brother.
I am allso amased ,i wounder if what you are seeing is a harmonic of the resonate frequence. i would of expecterd low k/c .but like you said RF blck magic.
G,day from Sydney Australia. You've got me thinking...
1. I like your hand oscilloscope and power supply.
2. The Tesla coil: why the varying frequency increment response to increase voltage.
3. I associate it with the windings of a transformer?
🌏🇦🇺
Let me know if I understand you correctly, because as you say, the coil is an open, the other end is not in the circuit. If I understand you correctly, you are saying that even though the coil has one wire open, it still has an effect on the circuit because it is a COIL (inductance) in an AC driven circuit. So, in a DC circuit, the coil will resist the flow of current through the coil when power is first applied, even though t other wire is not tied into the "Circuit".? Am I correct? I mean when you flip the switch and apply a voltage, instantaneously, this coil will take on a charge and an electromagnetic charge in response to this power being applied to it, (power might not be the correct word. Voltage maybe?). The fact it is there, even if un-terminated, does have an affect on the rest of the circuit. Is that thought correct? But we are talking resonance of a coil, so an AC signal. And as you progressively increase the frequency of your signal generator, You were looking for peak voltage to see at what frequency the coil ADDED to the output measured voltage level. That is resonance. Just like in a shower... if you hit a not as you sing up and down in a scale of notes, at some point the oscillations of the frequency of your voice will vibrate the walls of the shower and make you sound amazing! That is the resonate frequency of your shower enclosure. AND the same circuit, without your open-ended coil would respond..... how? Differently I suppose. So the coil had an affect and the point of the frequency you applied to the circuit with the open-ended coil IN the circuit tells you the resonant frequency of that coil? Am I correct in understanding your point? Because the open-ended coil in the circuit adds to the output signal Peak-to-peak value at the output, the open-ended coil must be resonating and adding to the voltage at a certain frequency. Is that correct?
That is amazing. I believe it and I can understand it. It makes sense to me and you showed it happening. Thank you, Paul! I learned something, yet again, from your channel!
Major difference in diameter can affect resonate due to field strength.
And skin-effect of the diameter of the wire, correct? Because current in an AC circuit tends to flow on the outer surface of a wire's diameter, if I am not mistaken.
I am sorry pal but this is not the resonance that you are measuring....you are measuring the opposite which is the attenuation freq of the coil. And if I were you I would try VASTLY different coils and see if they all cop-out @4.7MHZ ~+-1-2% because that may just be a limmiting factor of your Signal Gen or a consequence of the SigGen. I like to image Reso as a gatway to a different place when all conditions are right ....there is a spike an opening as it were not a dip or close door.
FLUX CAPACITANCE!
Not looking good for the Steelers tonight.