# I Way of producing 600kHz longitudinal waves - Piezo or siren

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1. Nov 3, 2015

8. Nov 3, 2015

### AlgoryThm

About electromagnets, I think of the same principle of working as in loudspeakers.

9. Nov 4, 2015

### elegysix

If the signal is dissipated rapidly (in comparison at least) into heat, I can't justify any standard use for it other than a water heater.

Maybe you could look for a water tank heater based on this effect or something? - you never know.

10. Nov 4, 2015

### AlgoryThm

Thank you elegysix for your response to my issue. Well, it's not just "a heater"...It's THE heater! We are talking about great efficiency here. For example, supposedly, if water tank with 4lt of water needs 10.000 watts of energy to raise the temperature from 40 to 80C degrees in 3 minutes, this device would need half of that power! The phenomenon belongs to sympathetic vibratory physics sector and a guy called Peter Davey, who used to play sax, has done the same thing using two pieces of metals, cut properly and inserted one inside the other so they resonate and the two of them, when plugged to mains, produce almost infinite harmonics. It boils a glass of water almost instantly! This is what I'm trying to study, with more precision though. So it's not a common phenomenon and not one that is commercially available yet, that's for sure. Thanks for asking though :-)

11. Nov 4, 2015

### sophiecentaur

Overall efficiency (Heatout/kWhin) you would need to consider the efficiency of the 600kHz source, the transducer and the matching system. For sheer efficiency, you really have a hard job to beat an electrical element immersed in the water in a lagged tank. Where else can the heat escape to? You couldn't expect to do better than Heat out = Power In
An absorption phenomenon due to resonance is an interesting thing to study and wouldn't require high powers. If the efficiency of your transducer is not important then you could try a number of electro-acoustic ideas. I wondered about a 600kHz RF tuned circuit with the inductor bolted to a diaphragm. But there again, you have to ask why that's not already been done for cheap commercial devices. A piezoelectric transducer is, effectively, just an equivalent RLC circuit, to which the driver will (presumably) be tuned, if they want efficiency.
600kHz is either not popular to make because it is a difficult frequency range or because "there's no demand for it Sir". A chat with a technical department could leave you very well informed about these matters and could result in some useful advice. Techies are real suckers when you ask them about what they know. (To wit, PF )
PS
You must mean Joules of energy?

12. Nov 4, 2015

### CWatters

Great efficiency? Your figures suggest it would take around 5kW to put 3.7kW into the water. That's about 74% efficient.

Have you considered a immersed resistive heating element which should be close to 100% efficient?

Edit: For completeness...

Power = 4186 * 4 * 40 / 180 = 3.7kW

13. Nov 4, 2015

Staff Emeritus
Yes you are. You're claiming almost 200%. This is impossible. If Davey claims this, then Davey is a crackpot.

14. Nov 4, 2015

Staff Emeritus
I agree, those numbers don't work out. But he's claiming twice as efficient, and given that electrical heaters are 98-99% efficient, those numbers are even more impossible.

15. Nov 4, 2015

### Staff: Mentor

Closed pending moderation.

16. Nov 4, 2015

### Staff: Mentor

We do not discuss crackpottery at the PF. Your thread will remain closed.