On Tue, 10 Nov 2015 21:23:26 -0500, legg <legg@nospam.magma.ca> wrote:>On Tue, 10 Nov 2015 23:02:39 +0100, jeroen Belleman ><jeroen@nospam.please> wrote: > >>On 10/11/15 21:53, legg wrote: >>> On Mon, 09 Nov 2015 23:16:51 +0100, jeroen Belleman >>> <jeroen@nospam.please> wrote: >>> >>>> 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 >>> >>> Check your source impedance/current. Is it a fair trade? >>> >>> RL >>> >> >>Not the point. The argument was about using parametric effects to >>make oscillators. >> >>Come to think of it, I posted about another such thing, in an >>argument over using mains-frequency driven magnet coils to sustain >>a pendulum swinging at a ~1s period. That was a parametric >>oscillator too. >> >>Jeroen Belleman > >It's not gain. > >RLSure it is. The pendulum will swing forever, as long as the 60 Hz pump is there, overcoming frictional losses.
Magamp oscillator
Started by ●November 3, 2015
Reply by ●November 10, 20152015-11-10
Reply by ●November 10, 20152015-11-10
On Tue, 10 Nov 2015 21:23:26 -0500, legg <legg@nospam.magma.ca> wrote:>On Tue, 10 Nov 2015 23:02:39 +0100, jeroen Belleman ><jeroen@nospam.please> wrote: > >>On 10/11/15 21:53, legg wrote: >>> On Mon, 09 Nov 2015 23:16:51 +0100, jeroen Belleman >>> <jeroen@nospam.please> wrote: >>> >>>> 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 >>> >>> Check your source impedance/current. Is it a fair trade? >>> >>> RL >>> >> >>Not the point. The argument was about using parametric effects to >>make oscillators. >> >>Come to think of it, I posted about another such thing, in an >>argument over using mains-frequency driven magnet coils to sustain >>a pendulum swinging at a ~1s period. That was a parametric >>oscillator too. >> >>Jeroen Belleman > >It's not gain. >It's not an oscillator, either.
Reply by ●November 10, 20152015-11-10
On Tue, 10 Nov 2015 18:45:13 -0800, John Larkin <jjlarkin@highlandtechnology.com> wrote:>On Tue, 10 Nov 2015 21:23:26 -0500, legg <legg@nospam.magma.ca> wrote: > >>On Tue, 10 Nov 2015 23:02:39 +0100, jeroen Belleman >><jeroen@nospam.please> wrote: >> >>>On 10/11/15 21:53, legg wrote: >>>> On Mon, 09 Nov 2015 23:16:51 +0100, jeroen Belleman >>>> <jeroen@nospam.please> wrote: >>>> >>>>> 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 >>>> >>>> Check your source impedance/current. Is it a fair trade? >>>> >>>> RL >>>> >>> >>>Not the point. The argument was about using parametric effects to >>>make oscillators. >>> >>>Come to think of it, I posted about another such thing, in an >>>argument over using mains-frequency driven magnet coils to sustain >>>a pendulum swinging at a ~1s period. That was a parametric >>>oscillator too. >>> >>>Jeroen Belleman >> >>It's not gain. >> >>RL > >Sure it is. The pendulum will swing forever, as long as the 60 Hz pump >is there, overcoming frictional losses. >I don't see any gain. Wout = Win * ?
Reply by ●November 11, 20152015-11-11
On Tue, 10 Nov 2015 21:46:10 -0500, krw <krw@nowhere.com> wrote:>On Tue, 10 Nov 2015 21:23:26 -0500, legg <legg@nospam.magma.ca> wrote: > >>On Tue, 10 Nov 2015 23:02:39 +0100, jeroen Belleman >><jeroen@nospam.please> wrote: >> >>>On 10/11/15 21:53, legg wrote: >>>> On Mon, 09 Nov 2015 23:16:51 +0100, jeroen Belleman >>>> <jeroen@nospam.please> wrote: >>>> >>>>> 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 >>>> >>>> Check your source impedance/current. Is it a fair trade? >>>> >>>> RL >>>> >>> >>>Not the point. The argument was about using parametric effects to >>>make oscillators. >>> >>>Come to think of it, I posted about another such thing, in an >>>argument over using mains-frequency driven magnet coils to sustain >>>a pendulum swinging at a ~1s period. That was a parametric >>>oscillator too. >>> >>>Jeroen Belleman >> >>It's not gain. >> >It's not an oscillator, either.The 60 Hz pump trick adds energy to the resonant device, the pendulum, just as a transistor (or a varicap pump) adds energy to an LC. Adding energy keeps the oscillation from dying out. A pumped resonator is an oscillator. As a bonus, the parametric oscillator is phase-locked to the pump.
Reply by ●November 11, 20152015-11-11
jeroen Belleman <jeroen@nospam.please> wrote:> 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 10uYou need to check your values. LTspice defaults to 1e-3 ohm ESR for inductors. XL of a 1uH inductor is 603.688 ohms at 96.08meg. This gives a Q of 603,688, which is a bit beyond current technology. Similarly, the SRF of a 1uH inductor is around 200MHz. This gives a parallel capacitance of 0.63pf. Add 1.4pf for pad capacitance and you have around 2pf across the inductor. Put 6 ohms in series with the inductor to drop the Q to 100 at 100MHz, which is probably unattainable with ordinary commercial inductors, and look at your waveforms. The F/2 disappears after a few cycles. I'm not sure the model for the varactor is accurate. The datasheet shows a Q of 500 at 50MHz, but the model shows 5.41 ohms in series with the varactor diode, so the Q spec doesn't make sense. Version 4 SHEET 1 880 680 WIRE -16 80 -48 80 WIRE 80 80 -16 80 WIRE 208 80 144 80 WIRE 320 80 208 80 WIRE 384 80 320 80 WIRE 400 80 384 80 WIRE -48 96 -48 80 WIRE 208 96 208 80 WIRE 320 96 320 80 WIRE 400 96 400 80 WIRE 208 176 208 160 WIRE 320 176 320 160 WIRE -48 192 -48 176 WIRE 400 208 400 176 WIRE 400 304 400 288 FLAG 400 304 0 FLAG -48 192 0 FLAG 384 80 tank FLAG -16 80 pump FLAG 208 176 0 FLAG 320 176 0 SYMBOL varactor 144 64 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName D1 SYMATTR Value MV2201 SYMBOL ind 384 80 R0 SYMATTR InstName L1 SYMATTR Value 1� SYMATTR SpiceLine Rser=1u SYMBOL voltage -48 80 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V1 SYMATTR Value SINE(1 1 96.08meg) SYMBOL res 384 192 R0 SYMATTR InstName ESR SYMATTR Value 6 SYMBOL cap 192 96 R0 SYMATTR InstName PAD SYMATTR Value 1.4pf SYMBOL cap 304 96 R0 SYMATTR InstName SRF SYMATTR Value 0.63pf TEXT 160 8 Left 2 !.tran 1u TEXT 160 -24 Left 2 ;'F/2 Generator TEXT 416 192 Left 2 ;XL = 603.688 @ 96.08meg TEXT 416 288 Left 2 ;Q = 100.614 [Transient Analysis] { Npanes: 3 Active Pane: 1 { traces: 1 {524291,0,"V(tank)"} X: ('n',0,0,5e-008,5e-007) Y[0]: (' ',1,-4.2,0.6,3) Y[1]: ('_',0,1e+308,0,-1e+308) Volts: (' ',0,0,1,-4.2,0.6,3) Log: 0 0 0 GridStyle: 1 }, { traces: 1 {34603012,0,"I(D1)"} X: ('n',0,0,5e-008,5e-007) Y[0]: ('m',0,-0.008,0.002,0.01) Y[1]: ('_',0,1e+308,0,-1e+308) Amps: ('m',0,0,1,-0.008,0.002,0.01) Log: 0 0 0 GridStyle: 1 }, { traces: 1 {268959746,0,"V(pump)"} X: ('n',0,0,5e-008,5e-007) Y[0]: (' ',1,0,0.2,2) Y[1]: ('_',0,1e+308,0,-1e+308) Volts: (' ',0,0,1,0,0.2,2) Log: 0 0 0 GridStyle: 1 } }
Reply by ●November 11, 20152015-11-11
Same problem as before. If the ASC file has a value of 1u (1e-6), Microsoft may change it to some other Unicode character depending on which OS version you are running. These will be unreadable by others who are not running the same version. Or maybe it won't be readable by anyone. A suggested bypass is to omit symbols such as m, n, u, etc., and enter the value in exponential code such as 1e-3 = m, 1e-6 = u, 1e-9 = n, etc. Microsfot cannot screw that up.
Reply by ●November 11, 20152015-11-11
On Tue, 10 Nov 2015 20:01:54 -0800, John Larkin <jjlarkin@highlandtechnology.com> wrote:>On Tue, 10 Nov 2015 21:46:10 -0500, krw <krw@nowhere.com> wrote: > >>On Tue, 10 Nov 2015 21:23:26 -0500, legg <legg@nospam.magma.ca> wrote: >> >>>On Tue, 10 Nov 2015 23:02:39 +0100, jeroen Belleman >>><jeroen@nospam.please> wrote: >>> >>>>On 10/11/15 21:53, legg wrote: >>>>> On Mon, 09 Nov 2015 23:16:51 +0100, jeroen Belleman >>>>> <jeroen@nospam.please> wrote: >>>>> >>>>>> 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 >>>>> >>>>> Check your source impedance/current. Is it a fair trade? >>>>> >>>>> RL >>>>> >>>> >>>>Not the point. The argument was about using parametric effects to >>>>make oscillators. >>>> >>>>Come to think of it, I posted about another such thing, in an >>>>argument over using mains-frequency driven magnet coils to sustain >>>>a pendulum swinging at a ~1s period. That was a parametric >>>>oscillator too. >>>> >>>>Jeroen Belleman >>> >>>It's not gain. >>> >>It's not an oscillator, either. > >The 60 Hz pump trick adds energy to the resonant device, the pendulum, >just as a transistor (or a varicap pump) adds energy to an LC. Adding >energy keeps the oscillation from dying out. > >A pumped resonator is an oscillator. As a bonus, the parametric >oscillator is phase-locked to the pump. >You obviously consider the pendulum an oscillator but I think you're alone. I see it as nothing more than a tank. There is no amplification or feedback. What's the transfer equation?
Reply by ●November 11, 20152015-11-11
On Tue, 10 Nov 2015 20:01:54 -0800, John Larkin <jjlarkin@highlandtechnology.com> wrote:>On Tue, 10 Nov 2015 21:46:10 -0500, krw <krw@nowhere.com> wrote: > >>On Tue, 10 Nov 2015 21:23:26 -0500, legg <legg@nospam.magma.ca> wrote: >> >>>On Tue, 10 Nov 2015 23:02:39 +0100, jeroen Belleman >>><jeroen@nospam.please> wrote: >>> >>>>On 10/11/15 21:53, legg wrote: >>>>> On Mon, 09 Nov 2015 23:16:51 +0100, jeroen Belleman >>>>> <jeroen@nospam.please> wrote: >>>>> >>>>>> 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 >>>>> >>>>> Check your source impedance/current. Is it a fair trade? >>>>> >>>>> RL >>>>> >>>> >>>>Not the point. The argument was about using parametric effects to >>>>make oscillators. >>>> >>>>Come to think of it, I posted about another such thing, in an >>>>argument over using mains-frequency driven magnet coils to sustain >>>>a pendulum swinging at a ~1s period. That was a parametric >>>>oscillator too. >>>> >>>>Jeroen Belleman >>> >>>It's not gain. >>> >>It's not an oscillator, either. > >The 60 Hz pump trick adds energy to the resonant device, the pendulum, >just as a transistor (or a varicap pump) adds energy to an LC. Adding >energy keeps the oscillation from dying out. > >A pumped resonator is an oscillator. As a bonus, the parametric >oscillator is phase-locked to the pump. >I don't see it as being phase locked, any more than an LC is phase locked (its dual), either.
Reply by ●November 11, 20152015-11-11
Reply by ●November 11, 20152015-11-11
On Tue, 10 Nov 2015 20:01:54 -0800, John Larkin <jjlarkin@highlandtechnology.com> wrote: <snip>>The 60 Hz pump trick adds energy to the resonant device, the pendulum, >just as a transistor (or a varicap pump) adds energy to an LC. Adding >energy keeps the oscillation from dying out. > >A pumped resonator is an oscillator. As a bonus, the parametric >oscillator is phase-locked to the pump. >As a minus, it must be phase-locked to the pump..... Why bother using a varicap? It's spice, after all. 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 ind 272 112 R0 SYMATTR InstName L1 SYMATTR Value .25� SYMBOL voltage 144 240 R0 WINDOW 123 0 0 Left 2 WINDOW 39 24 124 Left 2 SYMATTR InstName V1 SYMATTR Value SINE(1 1 96.08meg) SYMBOL diode 128 96 R0 SYMATTR InstName D2 SYMATTR Value 1SR154-400 TEXT 176 24 Left 2 !.tran 0 1u .9u
