A Real Sonic Screwdriver?

dnnc2113

i'm making a prototype sonic screwdriver, but i got a little device in the center between the lithium battery and the tube leading to the speaker and LED lights, that changes the frequency and hertz of the speaker, so when i test it, it gets that perfect note to unscrew stuff, and possible even achieve the brown note.

Lancelot59

Sounds nice. Post some pictures and schematics so we can see it.

Mech_Engineer

Don't feed the troll

Lancelot59

Ok then.

dr dodge

I have to wonder what health risks would be associated with thaat vibration. My wrists are on the edge of corp tnl, and I'd bet that thing, if not severly isolated, would drop me to tears after the first hand ful of 1/4-20's I pulled out

dr

The Chemist

brennanshaw took his information from the doctor who visual dictionary, most of those things dont exist. but i do believe that some day this technology will be invented, and i wish to dedicate myself to inventing this. though brennanshaw was incorrect, he has a point about the accoustic accelerator inside the anechoic chamber. this would give us some leverage in directing the waves partially in a direction...i shall look further into this. though the problem would be how to make an anechoic chamber that small would require either sound proof glass or thermal insulation, and the thermal insulation might absorb the sound which in this case is not what we want. I would also have to be able to find a high frequency emitter, as i believe that high frequency will inhibate better results due to the rapid wavelength. if you all would like i could post a rough sketch of what im thinking.

The Chemist

actually, the wave would not be used in this sense. the wave would be directed into the locking mechanism to push the pins to the shear line, though this seems highly impractical. your way makes more sense. cheers.

Sierios

Has anyone seen this? Directional sound! http://www.youtube.com/watch?v=HF9G9M0cR0E
imagine a mixture of these small panels on the tip of the screwdriver cooperating with different frequencies!

The Chemist

this is very interesting. it would greatly increase the accuracy of the sound wave, and as he said, the sound is not coming from the transmitter, its being created at billions of points between the surface of the panel and the destination. The means its the air itself that is vibrating.

If you could aim it at a door lock, those points of vibration would be the pins. These vibrations would cause movement of the pins, but in theory, there would be no force of work. This device would help in 'aiming' the wave, but not actually creating the forcing/working frequency. Thanks for the link mate.

777

you morron the sonic screwdriver is not a screwdriver how could you not know that!

Danger

No offense intended, genius, but "moron" has only one "r". Also, the punctuation at the end of your last sentence should have been "?" or "?!" for emphasis. "you" as your opening word should have been capitalized, and "morron" followed by a "." or a ":" or a "—". The following "the" should have been capitalized if you had used the "." Otherwise, it required different spacing.
Also, there should have been a "!" or at least a "." following your second use of "screwdriver". "how", therefore, should have been capitalized.

Mech_Engineer

LOL

Danger, grammar police aficianado I'm going to have to check my posts twice as hard when you're around...

Danger

Naw... yours have always been pretty coherent.

Doc Orion

Hi;

I had built a working sonic screwdriver once, a few years back.

It’s common knowledge that sound/vibration can effect physical structure:soldiers must break step before crossing a bridge, an opera singer can break a wine glass by hitting the proper note, and a helicopter can easily shake a house from a distance overhead. So it seemed to me to be just a matter of frequency and power.

To test the theory I used an old box from a disused piezo-speaker that had a pair of screws on its top as well as a standard stereo speaker. The speaker was connected to a medium-powered stereo amplifier that was being fed by a simple audio sine wave generator.

At a certain frequency the screws on the box began to turn fast and easily until they reached the bottom; at a higher frequency they slowly unscrewed themselves. This was resonance at work. Going one step farther, I placed the speaker up against a solid wood door and adjusted the frequency upward; at a certaain point the key in the door turned itself to the right although not with enough force to open the lock. The key could even be turned when the speaker was some distance from the door (basic Mechanical Engineering 101). At one point I even managed to get dinner plates to spin on the sound head. That was cool.

Once I knew the theory was right, I had to see if I could a practical screwdriver. I tried several ideas but what worked best was a standard piezo buzzer from Radio Shack. Driven at the right frequency and at high enough voltage, it could easily turn the screws on the ox from three to four inches. This was great but at 143 dB, this didn’t work too well for quiet breaking and entering at 3:00 in the morning; not to mention it hurt any bystanders. I decided that this had to work at a near ultrasonic frequency, say 13 kHz. This was a frquency most people could only barely hear. By itself, this frequency didn’t turn the screws too well (resonance effects end at 10 kHz) but when either frequency or amplitude modulated, that worked the same as being used at an audible frequency. It could still be heard, but only because of the secondary modulation—if set for 10 Hz, one would hear the 10 Hz beat and not the 13 kHz even though it was mouch louder.

The final problem to be solved was the size. The SS took a lot of power. One couldn’t use big batteries or carry a battery pack; tat was tacky. The solution came when some company produced a neat little IC that could easily boost 3 volts to 9 VDC. Instead of big batteries, I only needed two sub-C to get all the power the SS needed. When it was finished, the sonic screwdriver was about 11 inches long; a little shorter than the 5th Doctor’s screwdriver (I had a chance to ask Peter Davidson about it once). Made out of aluminum and copper, it was a thing of beauty. Its only design flaw was the on/off switch: I could never get that like on TV. :-)

Eventually, somehow, it got lost...

‘Doc

The Chemist

men, this is science at its best. thank you very much for the information, i believe you have given hope to many of us doctor who geeks. mabye one day when im not poor im build one, but nonetheless, thanks a lot!

Doc Orion

Romana had her own sonic screwdriver. I had seen it briefly on a few Doctor Who shows but for years I never could find a picture of it; I had the impression that it was rather simple looking.

When I finally saw a picture, I was disappointed: it looked like a metal tooth-pick! The design is simpler than the Doctor's (which is why he tried to steal it), and so is the electronics since it doesn't have a lot to do. Say a really simple 555 (for square wave) or a slightly more complex XR2206 (sine wave) oscillator working at 15 kHz; its output feeding a power transistor and a miniature audio transformer connected to a small [cylindrical] transducer.

The circuit is something that can be knocked together for a couple of bucks, on a small narrow piece of perfboard in less than an hour. But the finished device being so much simpler, one would have to physically touch the SS to whatever you want to affect because that tiny transducer won't radiate nearly as well as the design for the Doctor's screwdriver.

Still, it would make a cute little hi-tech toy for some would-be Time Lord. ;-)

'Doc

mugaliens

Having seen many variations on both electronic and mechanical screwdrivers (of which I own two, a shortie and a regular) no larger than a normal screwdriver, I'm...

Not impressed. I also own a sheetrock scredriver that's nearly the same size (the same size at the driving head) as a normal screwdriver.

So, still not impressed. They work exceptionally well, using conventional (motor/worm driven gearing). No advanced "sonics" involved.

And they're fairly inexpensive!

Now if you can produce a "sonic screwdriver" that'll drive a thousand deckscrews on a single charge, I'd be happy to take a look.