Oscillators without transistors

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Hello,

What are some examples of oscillators which don't require transistors or vacuum tubes?

So far I found relay oscillators and the Pearson-Anson oscillator.

Does the Pearson-Anson oscillator require a high-voltage neon lamp, or would it work on LEDs as well?
https://en.wikipedia.org/wiki/Pearson%E2%80%93Anson_effect

Relay oscillators look neat too but I don't imagine they would last very long at high frequencies.

https://www.youtube.com/watch?v=WuG4nOyF99s


Thanks,

Michael

Re: Oscillators without transistors
On 10/17/18 3:33 PM, snipped-for-privacy@gmail.com wrote:
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The neon bulb thing only works because the bulb turns itself off  
abruptly at low voltage, then doesn't turn on again immediately as the  
voltage recovers.  This hysteresis is why it works.

Other non-transistor, non-tube oscillators:

Electromechanical buzzers
Mechanical clock balance wheels
Coffee percolators
Baseball cards in bike spokes
Thermoacoustic refrigerators
Dog whistles
Ocarinas
Blowing over a beer bottle
Slinky going downstairs
Bay of Fundy
Internal combustion engine piston

Tunnel diode oscillator
SCR relaxation oscillator

Cheers

Phil Hobbs

--  
Dr Philip C D Hobbs
Principal Consultant
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Re: Oscillators without transistors
On Wednesday, October 17, 2018 at 12:47:33 PM UTC-7, Phil Hobbs wrote:
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Ah ok, thanks.  While I was at the university I was under the impression that one could create an oscillator with a combination of resistor, inductor and capacitor, but now I see most electronic oscillators require a transistor of some sort.

Michael

Re: Oscillators without transistors
:
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tor
stor
The spin-torque oscillator is magic.  It is a thin film structure with nano
meter-thick layers of normal conductors, ferromagnetic materials, and antif
erromagnetic materials.  Apply a dc current, and it continuously produces m
icrowave oscillations.  No active gain elements or resonators are required.

Re: Oscillators without transistors
On 10/18/18 8:12 PM, jfeng@my-deja.com wrote:
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There are also Gunn and IMPATT diode microwave oscillators.

Cheers

Phil Hobbs


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Dr Philip C D Hobbs
Principal Consultant
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Re: Oscillators without transistors
On 17/10/18 20:47, Phil Hobbs wrote:
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And, of course, there are a range of purely chemical oscillators
As good a starting point as any is
https://en.wikipedia.org/wiki/Chemical_oscillator


Re: Oscillators without transistors
On Wed, 17 Oct 2018 15:47:25 -0400, Phil Hobbs

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Carbon microphone and speaker.

Pendulum clock.

Arc oscillator (once used for broadcast transmission)

Violin.

Clarinet.

Zener diode.

Gunn diode.

Fingernail on blackboard.


--  

John Larkin         Highland Technology, Inc

lunatic fringe electronics  


Re: Oscillators without transistors

Negative resistance spark gap ?

High frequency alternator ?
As I recall, Fessenden used a 100 KHz generator to transmit music and  
voice in 1906.

David



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Re: Oscillators without transistors
On 17/10/18 20:33, snipped-for-privacy@gmail.com wrote:
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Tunnel diodes
Gunn diodes

Re: Oscillators without transistors
masers  
lasers
spin-torque oscillators


Re: Oscillators without transistors
On Wed, 17 Oct 2018 12:33:19 -0700 (PDT), snipped-for-privacy@gmail.com wrote:

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When I was in high school I built this rather elaborate relay
oscillator to dial a pulse type telephone.  One relay developed
pulses, another was rigged as a monostable to time the pulse train to
dial a particular number.  A rotary stepper relay could read the holes
in cards and cycle through some crude punch cards to dial (worked but
not well)

Scr's can be made to oscillate, of course unijunctions, some negative
resistance diodes like tunnel/gunn, electro-mechanical toys using
magnets and leaf/reed switches or transistors to energize coils,
old-time magnetic earphones and carbon mikes to develop feedback,
tuning forks with feedback drivers, propagation delay devices, arc
lights, early radio transmitters that used motors driving many-pole
alternators, spark-excited Tesla coils...

  

Re: Oscillators without transistors
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Was your high school project an electronic vibrator?

https://en.wikipedia.org/wiki/Vibrator_ (electronic)

Thank you, 73,

--  
Don Kuenz KB7RPU
There was a young lady named Bright Whose speed was far faster than light;
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Re: Oscillators without transistors
wrote:

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No but some years later I made a small air pump using a coil driving a
magnet.  Other than the heat it developed, it might have made a decent
vibrator (of the sex toy variety).

Re: Oscillators without transistors
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needs a gas discharge tube, spark gap, sidactor, tunnel diode, PUT, or
UJT etc - something with a negative resistance region, LED won't work.

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tesla coil. (and other spark gap oscillators)

car horn, dc electric bell (I guess these are really relay oscillators)

electric motor  

hot-wire   (wire heats up due to current and gets longer)  
eg: automotive blinker unit

bimetallic (metal changes shape in response to heat from an electric
heat source)
eg: stovetop simmerstat

carbon microphone feedback (I guess this is an accoustically coupled
analogue relay oscillator)



--  
  Notsodium is mined on the banks of denial.

Re: Oscillators without transistors
Old style doorbell or buzzer.

Re: Oscillators without transistors
On 10/17/2018 2:33 PM, snipped-for-privacy@gmail.com wrote:
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   There used to be signs that used movement to get attention, it could  
be as simple as a waving hand. The hand was setup as a pendulum and when  
the battery was installed you could give it a push, this would close a  
switch, energizing the solenoid and giving the pendulum a kick this  
would also open the switch. The pendulum would go through its swing and  
then come back and close the switch, repeating the cycle.
  I searched but could not fid a sign or a circuit, but I'm sure there is
one somewhere online.
  Variation of the relay oscillator.

                          Mikek

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Re: Oscillators without transistors
On 10/28/2018 10:40 PM, amdx wrote:
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The really fun one was the box with a trap door on top and a big toggle
switch on the front.  When you turned on the switch, a motor whirred and
a plastic hand came out of the box, turned the switch off again, then
went back into the box before the motor actually turned off.

I had a piggy bank that worked like that--you put the coin in a shallow
slot with two contacts at the bottom.  The coin completed the circuit,
and the hand came out and collected the coin.

Cheers

Phil Hobbs


--  
Dr Philip C D Hobbs
Principal Consultant
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Re: Oscillators without transistors
On Sun, 28 Oct 2018 21:40:50 -0500, amdx wrote:

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Sounds grossly inefficient. I'm reminded of those Chinese cat things with  
the waving paw. They seem to have got battery life down to a fine art;  
must be using a 'joule thief' or some variant thereof I would imagine.




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Re: Oscillators without transistors
On Tue, 30 Oct 2018 18:30:08 -0000 (UTC), Cursitor Doom

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The so-called joule thief is what was called a blocking oscillator
back in the days of vacuum tubes and you could find one in every tube
type TV. The flyback pulse produces a high voltage because the
tube/transistor is cut off abruptly, and the collapsing field produces
a voltage spike.  

Those moving display gizmos were neat, I used to play with them as a
kid.  A single D battery or pair of them could keep the thing swinging
for a week or two.  The magnet was on a half-circle of wire and
suspended so it would pass through the coil, working a leaf-switch of
a couple of phosphor bronze springs that would repel the magnet as it
passed the midpoint.  What is impressive was the length of time they's
keep working - particularly with the zinc carbon batteries we had in
those days.

Transistors cost money back then too.  My first blocking oscillator
using transistors was pulled from a Radio Electronics magazine for a
"sonic shake table" (an interesting gizmo that could make standing
waves in particles of flour in an upturned speaker cone - or mercury
if you happen to have some)  When I got tired of playing with it, I
added it to my bicycle for a horn and ran it off the hub mounted
alternator.

Re: Oscillators without transistors
The vibrator in an old car radio. Not only does it oscillate without transistors or tubes, some rectify without diodes. A second set of contacts make for a synchronous rectifier.  

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