If you download function generator software for your computer you can do this with just a computer and a oscilloscope. Just connect audio out from you PC with a 1K resistor in series, the frequency shown on the software is quite accurate.
if your function generator has low impedance output like 50 ohms, then you cant connect it directly across the tuned circuit. Connect via a 10k resistor for example otherwise your generator will dampen the tuned circuit. like wise your oscilloscope should be set to times 10 input. The counter also should be connected to the generator output, not across the tuned circuit.
With most the modern digital oscilloscopes having a frequency counter built in, you're not gonna need that I guess. Thanks a lot for sharing your method of determining the resonant frequency. :)
Wow it's been 11 years.... one thing is for sure: cheap function generators and oscilloscopes have become much more robust. You can measure the frequency by reading the output directly from the function generator, and even cross-check it against the measurements on the scope (because I trust my Rigol more than I trust my $100 amazon special waveform generator).
Theory is sound, i use similar method to test traps etc. (See my video). However your setup is not sound. You have too much stray capacitance and inductance from all the long leads and wires. Try to shorten everything and "tighten" the setup some...
Thank you for your video, I would like to Add that when frequency is in RF range, distributed capacitance and self- resonant frequency of certain coil becomes critical factor when testing high frequency tuned circuit.
HI, I'd like to know how one arth can i measure the frequency i get off an LC Tank. I have done the formula V = 1 / (2 * pi * sqrt ( L * C ) and got a frequency but when i checked it out on my multimeter or oscillascope DSO 062 it comes up with something else.
The capacitance of your measuring device will change the actual resonant frequency of the LC circuit a bit when you hook up to it. Make a pickup coil of about 20 tightly wound turns of insulated (preferably "magnet" enameled insulated type) wire an inch or two in diameter and hook your scope probe across that. (More turns may be required for lower radio frequencies.) Then bring this coil in proximity to the LC circuit's coil. It must be aligned with it, not at 90 degrees to it. Keep the scope's pickup coil as far from the LC circuit's coil as you can and still get a scope reading that will show the peak frequency at resonance. (You will want to use a low setting on the scope's voltage per division for this.) Now do the same for the signal generator, and keep its coil as far from the LC circuit as you can and still get coupling to the LC circuit being tested. This setup will give a minimum disturbance to the LC circuit's natural resonant frequency that is being tested.
Anybody have any advice as to how this could be done with high frequency (100-200MHz) filters? I'm using a network analzyer but I'd like another method(my function generator tops out at 10MHz)
Why don't you just read the frequency off the function generator ? The counter is more accurate of course, but the limit of precision is probably detecting the peak amplitude, rather than the calibration of your generator dial.
small application like this, should work but if you really want to optimize your project try to avoid stranded wire when you're wrapping coils, you really want an organized magnetic field and an organized flow of current forward and backward when it the field collapses. thin gauge magnet wire is the best wire to wrap coils with, it's worth the investment, but experiment and learn, use the stranded and see what your results are, it's always good to check other methods out and see if they work for you! :-)
By 104 I'm assuming you mean 100nF (0.1uF) 50v ceramic disc capacitor? As an instructional video it's quite informative, thanks, but you should watch out for throwing slang terms in if trying to teach people. Good effort.
If you download function generator software for your computer you can do this with just a computer and a oscilloscope. Just connect audio out from you PC with a 1K resistor in series, the frequency shown on the software is quite accurate.
Thank you David! You are a good teacher. Looking forward to more from you.
Thank you! I just got through watching a video of a guy saying that you're looking for 0V, not the peak....I was like, what?! That makes no sense.
You might have mentioned that the frequency counter is not required since the frequency can be easily determined using the oscilloscope.
if your function generator has low impedance output like 50 ohms, then you cant connect it directly across the tuned circuit. Connect via a 10k resistor for example otherwise your generator will dampen the tuned circuit. like wise your oscilloscope should be set to times 10 input. The counter also should be connected to the generator output, not across the tuned circuit.
I also thought the same... In fact to reduce the loading effect a high value resistor is required like10M Ohms Resistance is required.
Great video - the most clearly explained I've seen on this topic. Cheers.
With most the modern digital oscilloscopes having a frequency counter built in, you're not gonna need that I guess. Thanks a lot for sharing your method of determining the resonant frequency. :)
you can read time of one period from display than calc. frq.
Yap, that's possible also. But now a days I've seen that scopes show frequency directly on the display. :P
Thank you for the upload. Good explanation. I liked your video.
Real good job David.
Wow it's been 11 years.... one thing is for sure: cheap function generators and oscilloscopes have become much more robust. You can measure the frequency by reading the output directly from the function generator, and even cross-check it against the measurements on the scope (because I trust my Rigol more than I trust my $100 amazon special waveform generator).
Are you worried about essentially shorting out the signal generator?
simple and straight forward thanks for the vid
Great video.good explanation thank you
Great video ,just one thing you dont need frequency counter when you allready have your osciloscope just calculate.you have time on screen.
Did you make a simulated results to compare in experimental?
Sorry I missed the answer "What was the frequency of the coil" as you had two different ones? 131kHz or 406kHz Thank you
Could you have set the trigger level on the scope to fire at the peak signal? The scope would then measure the frequency more accurately?
Theory is sound, i use similar method to test traps etc. (See my video).
However your setup is not sound. You have too much stray capacitance and inductance from all the long leads and wires.
Try to shorten everything and "tighten" the setup some...
I was about to comment the same thing, the ESL would mess stuff up here
Thank you for your video, I would like to Add that when frequency is in RF range, distributed capacitance and self- resonant frequency of certain coil becomes critical factor when testing high frequency tuned circuit.
did u intentionally blur the video?
Well done. Even basic stuff re-done shows a verification of scientific understanding, which is better than hear-say.
HI, I'd like to know how one arth can i measure the frequency i get off an LC Tank. I have done the formula V = 1 / (2 * pi * sqrt ( L * C ) and got a frequency but when i checked it out on my multimeter or oscillascope DSO 062 it comes up with something else.
The capacitance of your measuring device will change the actual resonant frequency of the LC circuit a bit when you hook up to it.
Make a pickup coil of about 20 tightly wound turns of insulated (preferably "magnet" enameled insulated type) wire an inch or two in diameter and hook your scope probe across that. (More turns may be required for lower radio frequencies.) Then bring this coil in proximity to the LC circuit's coil. It must be aligned with it, not at 90 degrees to it. Keep the scope's pickup coil as far from the LC circuit's coil as you can and still get a scope reading that will show the peak frequency at resonance. (You will want to use a low setting on the scope's voltage per division for this.) Now do the same for the signal generator, and keep its coil as far from the LC circuit as you can and still get coupling to the LC circuit being tested. This setup will give a minimum disturbance to the LC circuit's natural resonant frequency that is being tested.
Does the unit of frequency is 1/s? or rad/s? or does the frequency is the angular frequency (w) or just normal physical (f) ?frequency?
it would be better after final check, disconnect coil and let guys know how change osciloscope with or without coil after and before Thanks
thank you for this video!
Great video thanks
Anybody have any advice as to how this could be done with high frequency (100-200MHz) filters? I'm using a network analzyer but I'd like another method(my function generator tops out at 10MHz)
Thank you for this.
Why don't you just read the frequency off the function generator ? The counter is more accurate of course, but the limit of precision is probably detecting the peak amplitude, rather than the calibration of your generator dial.
Or get it from the oscilloscope.
will a stranded wire coil work?
small application like this, should work but if you really want to optimize your project try to avoid stranded wire when you're wrapping coils, you really want an organized magnetic field and an organized flow of current forward and backward when it the field collapses. thin gauge magnet wire is the best wire to wrap coils with, it's worth the investment, but experiment and learn, use the stranded and see what your results are, it's always good to check other methods out and see if they work for you! :-)
Good video
By 104 I'm assuming you mean 100nF (0.1uF) 50v ceramic disc capacitor? As an instructional video it's quite informative, thanks, but you should watch out for throwing slang terms in if trying to teach people. Good effort.
Or you could use a dip meter....
Ur tha werst teecher in tha wurld hàhà usuk ballz
LOL
The VERY MODEL of a useless disorganized video with a camera that is never held still.
What a rats nest.