On 11/06/2015 05:29 PM, jeroen Belleman wrote:> On 06/11/15 21:50, John Larkin wrote: >> On Wed, 4 Nov 2015 08:55:37 +0000, piglet <erichpwagner@hotmail.com> >> wrote: >> >>> On 03/11/2015 10:45, Piotr Wyderski wrote: >>>> Is it at all possible to build an oscillator entirely from >>>> non-linear magnetics (OK, solid state diodes are allowed)? >>>> >>>> Best regards, Piotr >>> >>> There is such a thing as the "parametric transformer" about which I know >>> nothing but assuming it works like a varactor diode parametric amplifier >>> then I suppose it could be made to oscillate, I guess it needs a higher >>> frequency pump to provide the power source? >>> >>> piglet >> >> Right. Core saturation creates a nonlinear element that can do things, >> but it needs an AC pump. >> >> Here is a diode acting like a subharmonic oscillator. Same sort of >> idea. >> >> https://dl.dropboxusercontent.com/u/53724080/Circuits/Oscillators/SubHarmonic.jpg >> >> >> Quick proof-of-concept hack. Could be optimized. > > You brought this up some time ago when I asked about passive > circuits generating lower frequencies from a single higher input > frequency. (The equivalent of what a BBO crystal does with light.) > > But this doesn't work. What you're really seeing in this circuit > is just the switch-on transient response of the tank, and which > dies out pretty quickly. > > Jeroen BellemanI don't understand your point. The waveform is periodic with twice the period of the fundamental, but not at the fundamental frequency. How is that not a subharmonic? Degenerate parametric amps (pump = input) can also generate subharmonics--you can buy packaged "frequency halvers" that just use varactors. See e.g. http://tinyurl.com/p5kpgbj Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
Magamp oscillator
Started by ●November 3, 2015
Reply by ●November 7, 20152015-11-07
Reply by ●November 7, 20152015-11-07
On Fri, 06 Nov 2015 23:29:54 +0100, jeroen Belleman <jeroen@nospam.please> wrote:>On 06/11/15 21:50, John Larkin wrote: >> On Wed, 4 Nov 2015 08:55:37 +0000, piglet <erichpwagner@hotmail.com> >> wrote: >> >>> On 03/11/2015 10:45, Piotr Wyderski wrote: >>>> Is it at all possible to build an oscillator entirely from >>>> non-linear magnetics (OK, solid state diodes are allowed)? >>>> >>>> Best regards, Piotr >>> >>> There is such a thing as the "parametric transformer" about which I know >>> nothing but assuming it works like a varactor diode parametric amplifier >>> then I suppose it could be made to oscillate, I guess it needs a higher >>> frequency pump to provide the power source? >>> >>> piglet >> >> Right. Core saturation creates a nonlinear element that can do things, >> but it needs an AC pump. >> >> Here is a diode acting like a subharmonic oscillator. Same sort of >> idea. >> >> https://dl.dropboxusercontent.com/u/53724080/Circuits/Oscillators/SubHarmonic.jpg >> >> Quick proof-of-concept hack. Could be optimized. > >You brought this up some time ago when I asked about passive >circuits generating lower frequencies from a single higher input >frequency. (The equivalent of what a BBO crystal does with light.) > >But this doesn't work. What you're really seeing in this circuit >is just the switch-on transient response of the tank, and which >dies out pretty quickly. > >Jeroen BellemanWell, I said it needs optimization. It should be possible to make this work.
Reply by ●November 8, 20152015-11-08
On 07/11/15 17:02, John Larkin wrote:> On Fri, 06 Nov 2015 23:29:54 +0100, jeroen Belleman > <jeroen@nospam.please> wrote: > >> On 06/11/15 21:50, John Larkin wrote: >>> On Wed, 4 Nov 2015 08:55:37 +0000, piglet <erichpwagner@hotmail.com> >>> wrote: >>> >>>> On 03/11/2015 10:45, Piotr Wyderski wrote: >>>>> Is it at all possible to build an oscillator entirely from >>>>> non-linear magnetics (OK, solid state diodes are allowed)? >>>>> >>>>> Best regards, Piotr >>>> >>>> There is such a thing as the "parametric transformer" about which I know >>>> nothing but assuming it works like a varactor diode parametric amplifier >>>> then I suppose it could be made to oscillate, I guess it needs a higher >>>> frequency pump to provide the power source? >>>> >>>> piglet >>> >>> Right. Core saturation creates a nonlinear element that can do things, >>> but it needs an AC pump. >>> >>> Here is a diode acting like a subharmonic oscillator. Same sort of >>> idea. >>> >>> https://dl.dropboxusercontent.com/u/53724080/Circuits/Oscillators/SubHarmonic.jpg >>> >>> Quick proof-of-concept hack. Could be optimized. >> >> You brought this up some time ago when I asked about passive >> circuits generating lower frequencies from a single higher input >> frequency. (The equivalent of what a BBO crystal does with light.) >> >> But this doesn't work. What you're really seeing in this circuit >> is just the switch-on transient response of the tank, and which >> dies out pretty quickly. >> >> Jeroen Belleman > > Well, I said it needs optimization. It should be possible to make this > work. > >Not with an ordinary Schottky diode it isn't. With a tunnel diode, it should be possible. Jeroen Belleman
Reply by ●November 8, 20152015-11-08
On 07/11/15 16:36, Phil Hobbs wrote:> On 11/06/2015 05:29 PM, jeroen Belleman wrote: >> On 06/11/15 21:50, John Larkin wrote: >>> On Wed, 4 Nov 2015 08:55:37 +0000, piglet <erichpwagner@hotmail.com> >>> wrote: >>> >>>> On 03/11/2015 10:45, Piotr Wyderski wrote: >>>>> Is it at all possible to build an oscillator entirely from >>>>> non-linear magnetics (OK, solid state diodes are allowed)? >>>>> >>>>> Best regards, Piotr >>>> >>>> There is such a thing as the "parametric transformer" about which I >>>> know >>>> nothing but assuming it works like a varactor diode parametric >>>> amplifier >>>> then I suppose it could be made to oscillate, I guess it needs a higher >>>> frequency pump to provide the power source? >>>> >>>> piglet >>> >>> Right. Core saturation creates a nonlinear element that can do things, >>> but it needs an AC pump. >>> >>> Here is a diode acting like a subharmonic oscillator. Same sort of >>> idea. >>> >>> https://dl.dropboxusercontent.com/u/53724080/Circuits/Oscillators/SubHarmonic.jpg >>> >>> >>> >>> Quick proof-of-concept hack. Could be optimized. >> >> You brought this up some time ago when I asked about passive >> circuits generating lower frequencies from a single higher input >> frequency. (The equivalent of what a BBO crystal does with light.) >> >> But this doesn't work. What you're really seeing in this circuit >> is just the switch-on transient response of the tank, and which >> dies out pretty quickly. >> >> Jeroen Belleman > > I don't understand your point. The waveform is periodic with twice the > period of the fundamental, but not at the fundamental frequency. How is > that not a subharmonic? > > Degenerate parametric amps (pump = input) can also generate > subharmonics--you can buy packaged "frequency halvers" that just use > varactors. See e.g. http://tinyurl.com/p5kpgbj > > Cheers > > Phil Hobbs >It doesn't work. The observed double-period component is just the tank ringing from the start-up transient. It doesn't last. Look at the waveforms a bit later: There is no trace of a double-period signal to be seen. Jeroen Belleman
Reply by ●November 8, 20152015-11-08
On Sun, 08 Nov 2015 23:23:33 +0100, jeroen Belleman <jeroen@nospam.please> wrote:>On 07/11/15 17:02, John Larkin wrote: >> On Fri, 06 Nov 2015 23:29:54 +0100, jeroen Belleman >> <jeroen@nospam.please> wrote: >> >>> On 06/11/15 21:50, John Larkin wrote: >>>> On Wed, 4 Nov 2015 08:55:37 +0000, piglet <erichpwagner@hotmail.com> >>>> wrote: >>>> >>>>> On 03/11/2015 10:45, Piotr Wyderski wrote: >>>>>> Is it at all possible to build an oscillator entirely from >>>>>> non-linear magnetics (OK, solid state diodes are allowed)? >>>>>> >>>>>> Best regards, Piotr >>>>> >>>>> There is such a thing as the "parametric transformer" about which I know >>>>> nothing but assuming it works like a varactor diode parametric amplifier >>>>> then I suppose it could be made to oscillate, I guess it needs a higher >>>>> frequency pump to provide the power source? >>>>> >>>>> piglet >>>> >>>> Right. Core saturation creates a nonlinear element that can do things, >>>> but it needs an AC pump. >>>> >>>> Here is a diode acting like a subharmonic oscillator. Same sort of >>>> idea. >>>> >>>> https://dl.dropboxusercontent.com/u/53724080/Circuits/Oscillators/SubHarmonic.jpg >>>> >>>> Quick proof-of-concept hack. Could be optimized. >>> >>> You brought this up some time ago when I asked about passive >>> circuits generating lower frequencies from a single higher input >>> frequency. (The equivalent of what a BBO crystal does with light.) >>> >>> But this doesn't work. What you're really seeing in this circuit >>> is just the switch-on transient response of the tank, and which >>> dies out pretty quickly. >>> >>> Jeroen Belleman >> >> Well, I said it needs optimization. It should be possible to make this >> work. >> >> > >Not with an ordinary Schottky diode it isn't. With a tunnel diode, >it should be possible. > >Jeroen Belleman > >Varicap diodes were once popular as microwave parametric amplifiers, when other semiconductors were too slow. https://en.wikipedia.org/wiki/Parametric_oscillator#Parametric_amplifiers so I figure it can be a subharmonic oscillator, too. https://en.wikipedia.org/wiki/Parametric_oscillator
Reply by ●November 8, 20152015-11-08
On Sun, 08 Nov 2015 23:23:36 +0100, jeroen Belleman <jeroen@nospam.please> wrote:>On 07/11/15 16:36, Phil Hobbs wrote: >> On 11/06/2015 05:29 PM, jeroen Belleman wrote: >>> On 06/11/15 21:50, John Larkin wrote: >>>> On Wed, 4 Nov 2015 08:55:37 +0000, piglet <erichpwagner@hotmail.com> >>>> wrote: >>>> >>>>> On 03/11/2015 10:45, Piotr Wyderski wrote: >>>>>> Is it at all possible to build an oscillator entirely from >>>>>> non-linear magnetics (OK, solid state diodes are allowed)? >>>>>> >>>>>> Best regards, Piotr >>>>> >>>>> There is such a thing as the "parametric transformer" about which I >>>>> know >>>>> nothing but assuming it works like a varactor diode parametric >>>>> amplifier >>>>> then I suppose it could be made to oscillate, I guess it needs a higher >>>>> frequency pump to provide the power source? >>>>> >>>>> piglet >>>> >>>> Right. Core saturation creates a nonlinear element that can do things, >>>> but it needs an AC pump. >>>> >>>> Here is a diode acting like a subharmonic oscillator. Same sort of >>>> idea. >>>> >>>> https://dl.dropboxusercontent.com/u/53724080/Circuits/Oscillators/SubHarmonic.jpg >>>> >>>> >>>> >>>> Quick proof-of-concept hack. Could be optimized. >>> >>> You brought this up some time ago when I asked about passive >>> circuits generating lower frequencies from a single higher input >>> frequency. (The equivalent of what a BBO crystal does with light.) >>> >>> But this doesn't work. What you're really seeing in this circuit >>> is just the switch-on transient response of the tank, and which >>> dies out pretty quickly. >>> >>> Jeroen Belleman >> >> I don't understand your point. The waveform is periodic with twice the >> period of the fundamental, but not at the fundamental frequency. How is >> that not a subharmonic? >> >> Degenerate parametric amps (pump = input) can also generate >> subharmonics--you can buy packaged "frequency halvers" that just use >> varactors. See e.g. http://tinyurl.com/p5kpgbj >> >> Cheers >> >> Phil Hobbs >> > >It doesn't work. The observed double-period component is just the >tank ringing from the start-up transient. It doesn't last. Look >at the waveforms a bit later: There is no trace of a double-period >signal to be seen. > >Jeroen BellemanI think it will work if I get the values right.
Reply by ●November 9, 20152015-11-09
The paper I linked to (paywall unfortunately) talks about optimizing frequency halvers based on varactors and schottkys. All you need is a nonlinear capacitance, which all diodes have, and low enough loss. It should be possible to do it with a magamp too--it's a degenerate parametric oscillator. Cheers Phil Hobbs
Reply by ●November 9, 20152015-11-09
"Phil Hobbs" wrote in message news:5b517d7f-dd73-4995-807d-400579d14441@googlegroups.com...>It should be possible to do it with a magamp too--it's a degenerate >parametric oscillator. >Does that mean a magamp oscillator would be expected to produce frequencies of Fclk/N? Or, perhaps, *M/N for modest values thereof? I know very little about parametric amps... All the explanations are crap, which usually suggests that it's either a stupendously complex subject, or a preposterously simple one (which is merely being presented in a confusing manner as a barrier to entry, as many otherwise-simple academic subjects tend to do). Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: http://seventransistorlabs.com
Reply by ●November 9, 20152015-11-09
On Mon, 9 Nov 2015 12:59:46 -0600, "Tim Williams" <tiwill@seventransistorlabs.com> wrote:>"Phil Hobbs" wrote in message >news:5b517d7f-dd73-4995-807d-400579d14441@googlegroups.com... >>It should be possible to do it with a magamp too--it's a degenerate >>parametric oscillator. >> > > >Does that mean a magamp oscillator would be expected to produce >frequencies of Fclk/N? Or, perhaps, *M/N for modest values thereof? > >I know very little about parametric amps... All the explanations are >crap, which usually suggests that it's either a stupendously complex >subject, or a preposterously simple one (which is merely being presented >in a confusing manner as a barrier to entry, as many otherwise-simple >academic subjects tend to do). > >TimThe simplest parametric amp is a variable capacitor connecting an RF source to a resistive load. Change the cap and you can vary the load power. It takes a tiny amount of energy to change the capacitance of a mechanical variable cap or a varactor, so there is huge power gain. Rectify the RF output back to DC, and you have a DC-controlled, DC output amp with enormous power gain. But it needs the AC pump. There are some simple graphical ways to look at my (currently not working) parametric divider. And there is serious math, too. There are varicap-based parametric amplifiers, mixers, dividers, multipliers, and oscillators. Still used in microwave apps, apparently. It sounds like there was a telephone central-office 20 Hz ring generator that was a magamp based divide-by-3, off the 60 Hz line. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Reply by ●November 9, 20152015-11-09
On 09/11/15 13:08, Phil Hobbs wrote:> The paper I linked to (paywall unfortunately) talks about optimizing > frequency halvers based on varactors and schottkys. > > All you need is a nonlinear capacitance, which all diodes have, and > low enough loss. > [...]OK, I give in. Here is a simple circuit that generates a strong and persistent f/2 from an input at frequency f. Jeroen Belleman ======== Cut here ======== Version 4 SHEET 1 880 680 WIRE 240 80 144 80 WIRE 288 80 240 80 WIRE 144 96 144 80 WIRE 288 128 288 80 WIRE 144 208 144 160 WIRE 144 208 96 208 WIRE 144 256 144 208 WIRE 288 272 288 208 WIRE 144 352 144 336 FLAG 288 272 0 FLAG 144 352 0 FLAG 240 80 tank FLAG 96 208 pump SYMBOL varactor 128 96 R0 SYMATTR InstName D1 SYMATTR Value MV2201 SYMBOL ind 272 112 R0 SYMATTR InstName L1 SYMATTR Value 1� SYMBOL voltage 144 240 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V1 SYMATTR Value SINE(1 1 96.08meg) TEXT 176 24 Left 2 !.tran 10u
