Built a gyrator back in the '70s when I saw them used in a graphic equalizer. The advantage is for audio frequencies, the inductors become huge so doing it with small caps is easier and cheaper plus you don't get non-linearities of magnetics..
This monstrosity that he simulated though has so many weird nonlinearities in the rejection band that I'd rather deal with the pain of better component selection than have to deal with the pain of my "noise" getting aliased back into my signal in this weird and monstrous way :P
The dean of the electrical engineering department at my alma matter, the University of Calgary was "famous" for his patents that were used inside analog I.C.'s back in the day. The book "RC-Active Circuits: Theory and Design" written by Leonard T. Bruton has the "Frequency Dependent Negative Resistor" (FDNR) listed on page 43. These symbols are the ones shown in the video at 04:00 and are a branch of components that extend upon the original gyrator invention to identify "Generalized Impedance Converter" GIC circuit elements. Note that, unlike the gyrator, the FDNR components can be realised with fully floating terminals instead of having to ground one of the two like the gyrator. Fun stuff. Thank you IMSAI Guy!
We need more "gray beards" teaching the younger guys, there's a serious lack of talent now. I'm betting in 20 years most of the engineers won't be able to build an IC or many circuits without an existing design and A.I. help.
A gyrator is used to replace the telephone holding coil when a DC isolated transformer is used in a modem. These became extraordinary valuable in PCMCIA modems and laptop modems when US Robotics and Hayes were hot in the early 1990s.
Another interesting use for gyrators is in magnetic circuit analogies. Typically for magnetic circuit analogies we substitute a voltage source for a coil, resistance for reluctance, etc. It's an intuitive analogy but not very rigorous, namely because the product of its equivalents for voltage and current - magnetomotive force (mmf) and magnetic flux - does not come out to a power quantity. If instead we use gyrators as our magnetic sources and model permeance (reciprocal of reluctance) as capacitors, we get the gyrator-capacitor magnetic model. In this model mmf is still voltage, but current becomes rate of change of flux. These two quantities do multiply to power.
A gyrator around a single BJT or Darlington still finds common use in modems where it pretends to be a ridiculously large inductor across the line, so large it doesn't affect the audio frequencies, but is basically a 200R resistor at DC.
You can use the results from the normalized gyrators to calculate the potentiometer settings according to the given "real world" impedance and frequency. This should give you a very sharp decay at the upper frequency of the pass band.
I used to work with these all the time when designing high Q filters for use in telecom equipment designs (SF signalling convertors) back in the early to mid 80's.
Im glad you touched on this subject. Im no genius but when it comes to capacitor i always imagined they could inverted to act as an inductor rather then a cap. This video clarified alot of my thinking on the physics of it all.
Op amp with X4 ref. des. is powered from positive supply net "VC1" while other op amps are powered from "VC". It looks like a new net was created during copy& paste.
Thank you IMSAI GUY for creating such an interesting channel. I always wanted to know how AT&T decipher the touch tones phone signals on their telephone centers in 60s. They could use PLL but that was very expensive. Does this gyrator have anything to do with it?
There is a copy of the "Electric Filter Design Handbook" - Arthur B. Williams & Fred Taylor. On the Internet Archive. No link provided as RUclips doesn't like them. Thanks ISMAI Guy. Take care.
8:50 is it not maybe due to the graph being shown till -80dB and the microcap one until -160dB? Vertical also goes up to slightly above 0dB and in the simulation 40dB. Maybe the steepness is a visual thing.
The Microcap graph is a log-lin and the book is lin-lin. Can you do a lin-lin graph? You could just replace the R+Vr with the computed values. This whole thing exists in the ideal part universe until you build it.😁 The 0.685 is about 4300 Ohms rather than 3920+500. Best guess just looking at the two diagrams.
I think for your simulation you could reduce the freq. range to get more points around -3dB. Or set more points in another way. Probably it there (at -3dB) a lot of detail that is not calculated but interpolated. Hence "weird" looking. And to analyze maybe just build 1 stage. Would be less sharp, probably just 1st order.
*Abstract* This transcript details a video about the concept of "gyrators" in electronics. Gyrators are unique circuit elements that invert impedance, allowing for the transformation of capacitors into inductors and vice-versa. The speaker provides an overview of gyrators, delving into their history and applications. *Key Points* * *What is a Gyrator?* A gyrator is a non-reciprocal, two-port network element that inverts impedance. * *Gyrators vs. Inductors:* Gyrators allow the creation of "fake inductors" from capacitors, eliminating the need for bulky physical inductors in many filter designs. * *Circuit Examples:* The transcript details a complex gyrator-based filter design and explores its creation and simulation using the microcap software. * *Challenges:* The speaker highlights the complexity of the given gyrator-based filter, noting the difficulty in perfectly replicating its ideal behavior in simulation. *Additional Notes* * Gyrators have theoretical origins but found practical applications in electronics design. * While gyrators offer flexibility, the speaker favors more familiar filter design approaches (e.g., Sallen-Key filters). * The speaker acknowledges that high-end audio equipment may still benefit from gyrators due to their phase characteristics. Disclaimer: I used gemini ultra 1.0 (2024.02.21) to summarize the video transcript. This method may make mistakes in recognizing words
Hi, you could first simulate the original filter with Ls and Cs and compare the result with the gyrator one. Maybe the ringing is a characteristic of the filter itself.
Sir, You seem to be quite knoeledgeble on the subject but i'm having trouble getting a schematic of a small b/w tv. Can you help? Its a star lite model tv8380. Any help would be appreciated.
Built a gyrator back in the '70s when I saw them used in a graphic equalizer.
The advantage is for audio frequencies, the inductors become huge so doing it with small caps is easier and cheaper plus you don't get non-linearities of magnetics..
This monstrosity that he simulated though has so many weird nonlinearities in the rejection band that I'd rather deal with the pain of better component selection than have to deal with the pain of my "noise" getting aliased back into my signal in this weird and monstrous way :P
I remember me.
The dean of the electrical engineering department at my alma matter, the University of Calgary was "famous" for his patents that were used inside analog I.C.'s back in the day.
The book "RC-Active Circuits: Theory and Design" written by Leonard T. Bruton has the "Frequency Dependent Negative Resistor" (FDNR) listed on page 43. These symbols are the ones shown in the video at 04:00 and are a branch of components that extend upon the original gyrator invention to identify "Generalized Impedance Converter" GIC circuit elements. Note that, unlike the gyrator, the FDNR components can be realised with fully floating terminals instead of having to ground one of the two like the gyrator.
Fun stuff. Thank you IMSAI Guy!
We need more "gray beards" teaching the younger guys, there's a serious lack of talent now. I'm betting in 20 years most of the engineers won't be able to build an IC or many circuits without an existing design and A.I. help.
I was wondering if someone might comment on Dr. Bruton’s work. Thanks so much! He was my PhD supervisor and I had lunch with him not long ago.
A gyrator is used to replace the telephone holding coil when a DC isolated transformer is used in a modem. These became extraordinary valuable in PCMCIA modems and laptop modems when US Robotics and Hayes were hot in the early 1990s.
Another interesting use for gyrators is in magnetic circuit analogies. Typically for magnetic circuit analogies we substitute a voltage source for a coil, resistance for reluctance, etc. It's an intuitive analogy but not very rigorous, namely because the product of its equivalents for voltage and current - magnetomotive force (mmf) and magnetic flux - does not come out to a power quantity. If instead we use gyrators as our magnetic sources and model permeance (reciprocal of reluctance) as capacitors, we get the gyrator-capacitor magnetic model. In this model mmf is still voltage, but current becomes rate of change of flux. These two quantities do multiply to power.
Blast from the past. Back in the 1980s I was using gyrators for 2970Hz notch filters and tone detectors. I always felt they were magic :)
Same here, I used these for 2600Hz detectors and other detectors used for SF signalling convertors for Telecom use ;-).
A gyrator around a single BJT or Darlington still finds common use in modems where it pretends to be a ridiculously large inductor across the line, so large it doesn't affect the audio frequencies, but is basically a 200R resistor at DC.
Hi, I was looking into the SR850 SRS Lock-In amplifier schematics and there are a lot of gyrators there! Awesome!
You can use the results from the normalized gyrators to calculate the potentiometer settings according to the given "real world" impedance and frequency. This should give you a very sharp decay at the upper frequency of the pass band.
I used to work with these all the time when designing high Q filters for use in telecom equipment designs (SF signalling convertors) back in the early to mid 80's.
Im glad you touched on this subject. Im no genius but when it comes to capacitor i always imagined they could inverted to act as an inductor rather then a cap.
This video clarified alot of my thinking on the physics of it all.
Op amp with X4 ref. des. is powered from positive supply net "VC1" while other op amps are powered from "VC". It looks like a new net was created during copy& paste.
I think this kind of stuff has been replaced by digital filters these days.
Thank you IMSAI GUY for creating such an interesting channel. I always wanted to know how AT&T decipher the touch tones phone signals on their telephone centers in 60s. They could use PLL but that was very expensive. Does this gyrator have anything to do with it?
Thank you so much for your teaching ❤❤❤
I've played with it before ..... It's pretty cool!
Gyrator? Isn't that a circuit for a toy Elvis doll.
🕺
Seems to be good for an application where an extremely sharp cutoff point is needed.
There is a copy of the "Electric Filter Design Handbook" - Arthur B. Williams & Fred Taylor. On the Internet Archive. No link provided as RUclips doesn't like them. Thanks ISMAI Guy. Take care.
8:50 is it not maybe due to the graph being shown till -80dB and the microcap one until -160dB? Vertical also goes up to slightly above 0dB and in the simulation 40dB. Maybe the steepness is a visual thing.
Good for telephone line interface, provides simulation of a dc path and inductance to keep line off hook and ac coupled small audio transformer for ac
I've used the single transistor simulated inductor for IR input handling.
The Microcap graph is a log-lin and the book is lin-lin. Can you do a lin-lin graph? You could just replace the R+Vr with the computed values. This whole thing exists in the ideal part universe until you build it.😁 The 0.685 is about 4300 Ohms rather than 3920+500. Best guess just looking at the two diagrams.
I think for your simulation you could reduce the freq. range to get more points around -3dB. Or set more points in another way. Probably it there (at -3dB) a lot of detail that is not calculated but interpolated. Hence "weird" looking. And to analyze maybe just build 1 stage. Would be less sharp, probably just 1st order.
@4:50 I Must steal this book!
*Abstract*
This transcript details a video about the concept of "gyrators" in electronics. Gyrators are unique circuit elements that invert impedance, allowing for the transformation of capacitors into inductors and vice-versa. The speaker provides an overview of gyrators, delving into their history and applications.
*Key Points*
* *What is a Gyrator?* A gyrator is a non-reciprocal, two-port network element that inverts impedance.
* *Gyrators vs. Inductors:* Gyrators allow the creation of "fake inductors" from capacitors, eliminating the need for bulky physical inductors in many filter designs.
* *Circuit Examples:* The transcript details a complex gyrator-based filter design and explores its creation and simulation using the microcap software.
* *Challenges:* The speaker highlights the complexity of the given gyrator-based filter, noting the difficulty in perfectly replicating its ideal behavior in simulation.
*Additional Notes*
* Gyrators have theoretical origins but found practical applications in electronics design.
* While gyrators offer flexibility, the speaker favors more familiar filter design approaches (e.g., Sallen-Key filters).
* The speaker acknowledges that high-end audio equipment may still benefit from gyrators due to their phase characteristics.
Disclaimer: I used gemini ultra 1.0 (2024.02.21) to summarize the
video transcript. This method may make mistakes in recognizing words
Cadac use these (or similar) in the EQ on there mixers. Or at least did.
Is the gyrator better than other kind of filter or is it of no use anymore because digital filters are cheap and easy to build today ?
Hi, you could first simulate the original filter with Ls and Cs and compare the result with the gyrator one. Maybe the ringing is a characteristic of the filter itself.
can you just sweep the pots in the simulation?
A Monte Carlo of just the pots might show the best performance achievable.
Sir,
You seem to be quite knoeledgeble on the subject but i'm having trouble getting a schematic of a small b/w tv. Can you help? Its a star lite model tv8380. Any help would be appreciated.
ruclips.net/video/Ii--aTKocTA/видео.htmlsi=OsPu8SiIzgD8PRms
Is this a book??
What is the name of the first book?
The Art of Electronics Horowitz and Hill
😂😂