Magamp oscillator

Robert Baer · Nov 27, 2015

John Larkin wrote:

On Wed, 04 Nov 2015 08:49:10 -0800, Robert Baer
robertbaer@localnet.com> wrote:

John Larkin wrote:
On Tue, 3 Nov 2015 16:19:34 +0100, Piotr Wyderski
peter.pan@neverland.mil> wrote:

John Larkin wrote:

If you mean a DC powered circuit that oscillates using only passive
parts and diodes, no relays or such, I've never seen it done.

I'm not sure if you can call a magnetic amplifier a passive part.
It can exhibit admirable power gain, but needs to be powered by AC,
for example:

http://sparkbangbuzz.com/mag-audio-amp/mag-audio-amp.htm

The guy claims it has the gain of 2000. So recently, I have
started to wonder if you can use such a device as a DC-powered
oscillator. I agree, the answer "yes" would be a surprise, but
maybe it is "yes" indeed?

Best regards, Piotr

You can also make an amplifier or an oscillator using varicap and
rectifier diodes, but it also needs an AC pump.

Since nobody has done what you suggest in about 200 years of
tinkering, I suspect it can't be done.

And the bee cannot fly.

Some things are actually impossible.

Bees can obviously fly. What idiot decided that they can't?

If you can design an oscillator that meets Piotr's requirements, we'd
love to see it.

Been doing some modelling in head, as i do not know how to do Spice
nonlinear inductors, and a few other things.

Since nobody wants to tell how the Bell ring generator works, here
are some (known?) parameters needed to design one from scratch:
1. One non-linear inductor, value in order of 1Hy.
2. 60Hz drive "pump" signal.
3. Hybrid transformer used mainly to cancel the 60Hz from/at the output.
4. At least one non-polarized capacitor, value in order of 1uF.
5. Parametric amplifier design needed, may need another winding on
hybrid for feedback to oscillate.

There is an indication that DC might be used in place of the 60Hz
drive,but it seems to me that makes the start-up harder.

Robert Baer · Nov 27, 2015

Winfield Hill wrote:

jeroen Belleman 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 1ďż˝
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

Is that LTSpice? It complains, Multiple instances of "Flag"

I used LTSpice IV and saw no complaints.

Robert Baer · Nov 27, 2015

John Larkin 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

======== 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

Ooh, that's nice. The varicap is the nonlinear thing and the tank
capacitor simultaneously.

I had to change the L value to 1 uH; the "mu" symbol didn't survive
Usenet.

Nice! Stable after only 10 cycles input. Use "u" for micro symbol.

Robert Baer · Nov 27, 2015

John Larkin wrote:

On 10 Nov 2015 05:14:54 -0800, Winfield Hill
hill@rowland.harvard.edu> wrote:

jeroen Belleman 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 1ďż˝
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

Is that LTSpice? It complains, Multiple instances of "Flag"

I ran it in the current LT Spice, except that ? should be u.

It's amazing. Divides by 2 with gain!

It is a parametric amplifier; naturally there should be gain.

Robert Baer · Nov 27, 2015

piglet wrote:

On 09/11/2015 20:30, John Larkin wrote:

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.

Yes. The best known is possibly the Lorain Sub-cycler family:

http://www.telephonecollectors.info/index.php/document-repository/cat_view/185-bruce-crawford-library/198-lorain-products
* 200mA out with a measly 750 WATTS in????

The "decimonic" K5 produced 20Hz and 30Hz by para-amp action and then
mixed to generate 40Hz and 50Hz (10Hz spacing=decimonic) by a demonic
circuit shown in the download fig 8.

piglet
Got me confused WRT U.S. Coast Guard LORAN...

"Demonic"? Any ogres, griffons, witches or other nasties?

Robert Baer · Nov 27, 2015

John Larkin wrote:

On Wed, 11 Nov 2015 19:18:21 -0500, krw<krw@nowhere.com> wrote:

On Wed, 11 Nov 2015 13:05:45 -0500, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 11/11/2015 07:03 AM, krw wrote:
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?

You don't think that something that oscillates is an oscillator?

Well...

We're not alone. Wiki thinks that a pendulum is an oscillator.

https://en.wikipedia.org/wiki/Oscillation

https://en.wikipedia.org/wiki/Harmonic_oscillator#Simple_harmonic_oscillator

https://en.wikipedia.org/wiki/Harmonic_oscillator#Parametric_oscillators

A _driven_ pendulum may be an oscillator (under the proper conditions).

Joe Gwinn · Nov 28, 2015

In article <iwO5y.194687$qL.42162@fx15.iad>, Robert Baer
<robertbaer@localnet.com> wrote:

John Larkin wrote:
On Wed, 04 Nov 2015 08:49:10 -0800, Robert Baer
robertbaer@localnet.com> wrote:

John Larkin wrote:
On Tue, 3 Nov 2015 16:19:34 +0100, Piotr Wyderski
peter.pan@neverland.mil> wrote:

John Larkin wrote:

If you mean a DC powered circuit that oscillates using only passive
parts and diodes, no relays or such, I've never seen it done.

I'm not sure if you can call a magnetic amplifier a passive part.
It can exhibit admirable power gain, but needs to be powered by AC,
for example:

http://sparkbangbuzz.com/mag-audio-amp/mag-audio-amp.htm

The guy claims it has the gain of 2000. So recently, I have
started to wonder if you can use such a device as a DC-powered
oscillator. I agree, the answer "yes" would be a surprise, but
maybe it is "yes" indeed?

Best regards, Piotr

You can also make an amplifier or an oscillator using varicap and
rectifier diodes, but it also needs an AC pump.

Since nobody has done what you suggest in about 200 years of
tinkering, I suspect it can't be done.

And the bee cannot fly.

Some things are actually impossible.

Bees can obviously fly. What idiot decided that they can't?

If you can design an oscillator that meets Piotr's requirements, we'd
love to see it.

Been doing some modelling in head, as i do not know how to do Spice
nonlinear inductors, and a few other things.

Since nobody wants to tell how the Bell ring generator works, here
are some (known?) parameters needed to design one from scratch:
1. One non-linear inductor, value in order of 1Hy.
2. 60Hz drive "pump" signal.
3. Hybrid transformer used mainly to cancel the 60Hz from/at the output.
4. At least one non-polarized capacitor, value in order of 1uF.
5. Parametric amplifier design needed, may need another winding on
hybrid for feedback to oscillate.

There is an indication that DC might be used in place of the 60Hz
drive,but it seems to me that makes the start-up harder.

In the old days, it was simply a motor-generator that ran off 48 Vdc
(the main office battery) and generated 20 Hz. No electronics. A
mechanical commutator driven off the motor-generator shaft interrupted
the continuous 20 Hz into the one second on four seconds off AT&T ring
cadence. All five commutator phases were used, so the load on the 20
Hz generator was roughly constant.

Joe Gwinn

krw · Nov 28, 2015

On Thu, 26 Nov 2015 20:38:11 -0800, Robert Baer
<robertbaer@localnet.com> wrote:

John Larkin wrote:
On Wed, 11 Nov 2015 19:18:21 -0500, krw<krw@nowhere.com> wrote:

On Wed, 11 Nov 2015 13:05:45 -0500, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 11/11/2015 07:03 AM, krw wrote:
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?

You don't think that something that oscillates is an oscillator?

Well...

We're not alone. Wiki thinks that a pendulum is an oscillator.

https://en.wikipedia.org/wiki/Oscillation

https://en.wikipedia.org/wiki/Harmonic_oscillator#Simple_harmonic_oscillator

https://en.wikipedia.org/wiki/Harmonic_oscillator#Parametric_oscillators

A _driven_ pendulum may be an oscillator (under the proper conditions).

We've been over this (many times) but I propose that it also needs
feedback, else what's driving it is the oscillator and the pendulum is
a resonator (or filter).

Magamp oscillator

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