Diaphragm Thermoacoustic Engine (Miracle deer project)!

A thermoacoustics presentation here:

This is the latest version:

Compelling Engine
This engine forces the frequency
so works in a wide frequency range.
No adjusting problem.

How do it works?

Rezonator (outer piston with mass) moves but inner membrane follows with phase delay,
because gas behaves in the loop (due to the mass of the gas) as if it were a solid displace piston. 

Outer membrane is 40mm (pvc tube) wide and inner is 80mm (jam jar cap

Inner membrane is only on 10-15mm wide disc connects the rod.

So far, I have built twice, and immediately worked well.

I don't know how the engine changes when the pressure is higher (not atmospheric).
-iron mop handles about 20-30cm long:
-membranes thin rubber gloves

Previous versions:
You can not do fault in this model! 

This100% woks at first!

Keep the 40 mm and use thinner membrane!

Old versions (this are harder to be built):

What is the thermoacoustic generator?

Diaphragm Thermoacoustic Engine history and how does it work?

I was successful in my first standing-wave thermoacoustic experiment approximately spring of 2010. Unfortunately, I do not know the exact dates, because the forum ( Inrared's forum) was cracked where I wrote, and the datas are lost. Immediately I really liked how easy it is. I have read that the traveling-wave engine can give more power, but I could not built it.
 I had not even heard about the mechanical resonator, and I put to the closed end of the tube a membrane, which could vibrate with a nut. (this is a similar experiments in big size).
The idea came from this that if I made bypass loop and I put membrane in then it would support the standing wave and because membrane not solid a traveling wave would be also. I did not understand how the traveling-wave engine (TASHE) how works.
 When I tried it I felt that it works from less heat and is a little stronger. I have written to the competently, but they and others have said that it is only standing wave engine and not more. In addition I must heated conversely regenerator of the THASE.

They were right and not also. The membrane had too tiny surface and could not move so much gas that a traveling wave could be largely, but small stirling cycle was in it.  It is true also, that this engine works other ways than conventional TASHE engine. This configuration was always again and again in my mind and on my desk . In 2013 I started to use a wider membrane, and stirling cycle worked better. :

Although I already could do better engine than the standing wave, but it was still very weak. However,  I could modeling, and I was able to explorer different configurations also with this the broader membrane, and I concluded that this engine was not worse, in fact, probably better than others, and perhaps the large spaces are the reason that  these are  weak. Then I thought it is not necessary to widen the diameter of the pipe If I use a cone membrane.
 The cone membrane is soul of the engine and I call this displacer membrane.At first I used the pointed cone diaphragm, and I crucified out it with a piece of the stick. Here you can see in this video. I compared the standing wave and traveling one, when I use a rigid wall, then the cone membrane.
One problems was with pointed cone membrane. One that the stick pretty easily spotted the balloon (sharp edge of the pipe also  almost imperceptibly).
The long of the cone diaphragm about 4-5 cm long. When I tried to make a much longer, about 10 cm or more, engine did not work (maybe because of folds...) .
The tension of membrane. I can say that I tend to make a softer. If the membrane is not well done, the engine will not work. If you can do very well engine will work very well. Now engine can give energy for more than 100 LED (200-300). There is not better same size  heat engine on atmospheric pressure ...
The membrane is the difficulty. Sometimes I can make membrane well also only the fourth-fifth trying and there is that engine does not work.

Therefore, I made adjustable membrane:
Here Attila's video:

The engine itself is very simple. The most important part is the cone diaphragm.
If you are only using the resonator for a generator also, then it can produce the half of the maximum energy.
Essentially the cone membrane operates with a 90 degree phase shift and push the gas through the regenerator here and fro. That is because when the resonator membrane pushed or pulles the gas in the engine for first the air does not goes through the regenerator, because it is a resistance, but pushes the cone membrane which will return with a small delay and then pushes only through the gas on the regenerator. This time difference, ideally 90 degrees, is the Stirling cycle. We can adjust the rezonator membrane resonance with the weight to gas resonance( in the engine).

The membrane piston resonator does not seem so good when it is a generator also in one. Now it seems that I can extract more energy, if its is only function is to resonate freely, and I can use a other membrane for generator.
However, it may be when the resonator and generator same it is weaker because we can adjust more difficult the resonance!
The good frequency of the engine can be adjust with mass on the rezonator membrane.
I adhesives double-sided adhesive tape to different sized coins, and thus I try find the good mass and frequency, which delivers the most power on the generator membrane. The magnet and the diameter of coin on the membranes must be same. We must leave the resonator to vibrate free.
The precise mass adjusting the more powerful the engine.
Now it appears to be the engine stronger , if the resonator and the generator is not the same side.

Amateurs could not build the TASHE engine so far, because it  required very precise calculations.
This engine does not require such precise calculations we can adjust it with the masses.

I have tried longer engine, which means I used instead of 23 cm, over 55 cm long tubes.  I could make same electric energy power   but engine was difficult adjustable.

The part of the generator must build from paper or plastic because of the magnet.

I progressed further beyond 100+ LEDs:
- Better cone membrane
- I use thin membranes, but Be Careful Because the rubber gloves  very quickly will tear up at the coins.
- I use a new, uniform leds.
- I adjust the masses more perfectly.

How you can make this experiment:
The engine and cone membrane making.
small scissors:
hot glue gun:
soldering gun:

iron mop handle:
copper fittings 3 T (18mm):
2 L (18mm):
double-sided adhesive tape:
washing steel sponge:
Insulating tape:
2-40 white LED.
magnet 30x 5mm or smaller:
1 piece of 40 mm PVC pipe:
a few small coins:
copper wires
some balloon, or rubber gloves:

Tutorial videos:

Maybe cone long is better 40 mm
The parameters (weights and surfaces of the weights) of the resonator and generator the are different. The generator does not give the most energy  when it vibrates with the highest amplitude.


The my experimental generator. So this is an experimental ...
First, I made my coil based on this website
and I bought a such 30 x 5 mm neodymium magnet.
Here's Igor similar linear generator:
My first attempt was not good, because wire was too thick. So I use with a thin wire and more round at next coil (about 20mm x 5mm x 0,25), and it was good!

If you want only light leds you do not need any electronics. Leds must be even number, and parallel and you must connect them to coil with opposite polarity. But thus leds will blink.. If you charge something you need a electronics.

Other generator:

Paper cone membrane:
Adjusable cone membrane (but You need to use with membrane and mass and not a solid piston.)

Why is engine not working? update

possible errors:

If engine leaks a little it is not trouble.
It is not good if  an excessively big hole is somewhere on the engine .
Insulation tape seals very well, and it can be taken apart!
Use insulation tape!

masses must be adjusted..
First You must put 3-4 big coin or a bigger magnet (30mmx5mm) on  generator  membrane and after you have to try more- less coins on resonator membrane.

If engine does not work without the generator membrane
then  the mistake is the cone .

If the cone membrane is not good This error is in 99%:
You must do others (about 6 piece) and try those.
If membrane is good, engine works without  resonator membrane (and generator membrane) also, with only 1m long tube...(see my former engines)
You must build more different cone membrane or adjustable cone membrane. A made 6 piece, and one was good!

one of membrane has a hole

4, It may also be too thick and tight balloons.

5.First you need use alcohol burner, and not candle this is very important!

6. First You use not vibrating coil but vibrating magnet!

do you use such regenerator?


Other tips:
People always  try to build with differently  method the models and not perfect consider do it as it is in the description. The difference usually leads there that the engine will not work.
So you need try to make the engine exactly as it is in the tutrial .
Typically, the first engines are fails, because you do not have experience in it. Try again and again!
First you need build models and not a real engines!
If I can help, write!

Perseverance, more attempt, patience = Success
and engine will work well!
The time works for you.

The regenerator:
In this engine the regenerator is different, than conventional engines. It can be much longer and denser. :)
More soon..

Cooler experiment:


Simpler engine:
Engine tuning and finding the error was hard for most people.
This design may be a help for them.
We have simplicity to build the engine with only one pressure tank also.
It seems to me it is much weaker than the previous machine, but I do not know whether this is true.

The engine must be fixed strongly.

Miracle deer project

Guard the past, live the present, do for the future!
The forgotten knowledge of our the ancestors, that
we are not governing for the nature, we are only the part of it!
The Miracle Deer is the rebirth, the renewal,
and the sun symbol in the ancient Hungarian legends.
Now it is updated for a project name which mean
that a more than 200-year-old invention rebirths and
using the energy of the sun gives a chance also for the our reformation!
The invention of the past is the hope for the future:
The Stirling engine

DTE in the world:

Under pressure:
adjustable thermoacoustic generator

We need not for adjustable cone membrane under pressure! 

We need an adjustable mechanical resonator. 


Amikor növelem a nyomást, akkor nem a kúpmembránt kell állítani, mert arra nagyon-nagyon jó hatással van a túlnyomás.  1 bar-nál már szinte mindegy milyen feszes a kúpmembrán, mert nagyjából ugyanazt tudja nagyon széles feszítési tartományban. Tehát nincs szükség állítható kúpmembránra! Amit változtatni kell, az a rezonátor tömege. A regeneráló nyilván a tömörebb gáztól még nagyobb ellenállást jelent, és ahhoz,  hogy átmenjen rajta a gáz, nagyobb rezonátor tömegre van szüksége. Tehát ami alig működik, vagy olyan nagy tömeg, hogy nem is működik légköri nyomáson, az jól működik 1 baron. Légdugattyúval meg a cső hosszát kell növelni, ezt is nagyon szépen igazoltam kísérletekkel. A rövidebb cső jól működik légköri nyomáson, túlnyomáson már nem, csak a hosszabb. Persze a hosszabb cső, nagyobb veszteség, hiába növeljük a levegő tömegét, a hosszúságával, közben növekszik a "súrlódása", így nem is lehet ezeket a légdugattyús  gépeket túlságosan felfújni, vagy nagy mértékben kell ritkítani a stacket, vagy a regenerálót, de az is rontja a gépet. Tehát minél nagyobb a nyomás, úgy kell ezeknél a légdugattyús gépeknél a stacket, vagy a regenerálót ritkítani. Kivéve a mechanikai rezonátoros gépeknél, hiszen ott a nagyobb tömeg nem jár sokkal nagyobb súrlódással. A mechanikai rezonátoros gépek így nyomás alatt még inkább sokkal jobbak lesznek, mint légköri nyomáson. Pedig már úgy is jobbak. Ráadásul sokkal nagyobb nyomásra felfújhatóak, avval is növelik az előnyüket... És már több nagyságrendről beszélek... Hűtőnél persze nincs ilyen gond... Legalábbis elektromos meghajtásnál, mechanikai rezonátornál. Sokkal -sokkal erősebb lehet, mint a csőrezonátor. Amit viszont még nem értek, hogy 1 bar-on miért nem világít jobban a LED. Légkörin kisebb a tömeg, és ezért gyorsabb valamivel a frekvencia. Túlnyomáson nagyobb tömeg kell, és mivel nincs több mágnesem, és a mágnest rezegtetem most, az a mágnes ha nagyobb amplitúdóval is, de lassabb frekvencián rezeg, ugyanavval a mágneses térrel. Vennem kéne még két mágnest, és akkor talán többet adna le, és igazolhatnám, hogy többet tud nagyobb nyomáson. Ugyanakkor ugyanavval a mágneses térrel, illetve ugyanavval a generátorral (és frekivel) nagyobb nyomáson csak jobban kéne világítania.