Can Sound Waves Be Used to Turn a Screw Like a Sonic Screwdriver?

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The discussion explores the feasibility of using sound waves to turn screws, akin to a sonic screwdriver. While sonic vibrations can help loosen screws by breaking friction, controlled rotation remains uncertain. Some participants suggest that specific sound wave polarizations might achieve this, but practical applications and costs are questioned. Experimental attempts indicate that vibrations can influence the movement of screws and nuts, with varying results based on the method of application. Overall, while the concept of a sonic screwdriver is intriguing, significant technical challenges and limitations exist.
  • #51
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.
 
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  • #52
or put the screws in on both sides of the wall at the same time

dr
 
  • #53
dr dodge said:
or put the screws in on both sides of the wall at the same time

dr


Ahhh... I see. You want the kind of sonic screwdriver that the faux 11th Doctor had: handle made of wood, has a shaped metal piece for turning screws, and is sonic when you bang it against a wall heh heh.
 
  • #54
Doc Orion said:
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

nice, that makes sense. and hey, its the closest thing we have so far. any idea where i can get some of this stuff? future shop? radio shack? ebay?
 
  • #55
The Chemist said:
nice, that makes sense. and hey, its the closest thing we have so far. any idea where i can get some of this stuff? future shop? radio shack? ebay?
Digikey would be a good place to start.
 
  • #56
The Chemist said:
nice, that makes sense. and hey, its the closest thing we have so far. any idea where i can get some of this stuff? future shop? radio shack? ebay?

Best place is Mouser; you can get everything there except for the transducer-- that may be pretty hard to come by these days; the ceramics companies aren't as nice as they used to be to the experimenter. Ebay? Hmmm...

Just a reminder: smallness is the goal. Unless you are really skilled at working with surface mount parts, stick to 1/8 watt resistors and 16v tantalum caps. With creative wiring, it's amazing how compact you can get those circuits.

'Doc
 
  • #57
Lancelot59 said:
Digikey would be a good place to start.

Back in the day-- in those ancient times before the evil Bush monster plunged us into an economical Dark Age-- Radio Shack used to have a simple little kit used the TL499AC chip to make a 1.3v - 9v converter. One battery poduced 20 ma; two AA cells produced 60 ma at 9 VDC.

You can't get the kit any more, but I do think you can get the TL499AC chip by itself from Digikey. At least, they had it a few years ago... :-)
 
  • #58
Doc Orion said:
Back in the day-- in those ancient times before the evil Bush monster plunged us into an economical Dark Age-- Radio Shack used to have a simple little kit used the TL499AC chip to make a 1.3v - 9v converter. One battery poduced 20 ma; two AA cells produced 60 ma at 9 VDC.

You can't get the kit any more, but I do think you can get the TL499AC chip by itself from Digikey. At least, they had it a few years ago... :-)

http://search.digikey.com/scripts/DkSearch/dksus.dll?lang=en&site=US&WT.z_homepage_link=hp_go_button&KeyWords=TL499AC&x=26&y=27 Not the exact name though.
 
  • #59
I used the converter kit first to see if it could power my screwdriver which is more sophisticated than the Romana design.

The Romana design is less complicated-- only 1 chip (and somebody clever could probably do it with only a few transistors)-- but if the TL555 low power timer IC is used, it could be run off of a single battery or two, depending upon the battery used. Radio Shack has (still?) a 3.6 v ni-cad cell that might work.

Didn't there used to be a cylindrical 22 volt battery? Anyway, that would work nicely with a voltage regulator to drop the supply down to 15 volts. As Mr. Spock would say, there are always possibilities. One could even make a simple converter from a few spare parts--

http://www.rowan.sensation.net.au/electronics/stepup.html

Still, it's always good to have a few catalogs from battery companies sitting around; you never know what you might find that will make a sonic screwdriver smaller, more compact. :-)

'Doc
 
  • #60
At this website --

http://books.google.com/books?id=-s...&resnum=8&ved=0CEAQ6AEwBw#v=onepage&q&f=false


there are a number of basic transistor circuits that can make for great tiny driver circuits. Use two power transistors, work out the R/C values to get 13-15kHz operation, and use a miniature audio step-up transformer and it's finished. The screwdriver will easily operate at 1.5 volts.

The only problem is that the circuit will not only put out more power at 3.0 volts, but the frequency will change as the supply voltage changes. Of course, one could always use 3volts for maximum power to start with (you don't want to de-polerize the ceramic transducer) and at 13 kHz but as the power drops, so would the frequency. But hey, it's just a toy, right? <w>
 
  • #61
This is actually very interesting. I must consider myself a big Doctor Who fan myself, but I don't have a tremendous knowledge in Physics - I'm still learning at this point. :) But I would really like to build something like this, a device that uses sonic waves to perform actions such as loosening screws. I've read through this entire thread, but as I'm still quite new to physics, I'd greatly appreciate a little help with this topic. Does anyone have any handy tips or a simple guide or steps for me to follow to achieve this?

As I said, I'm looking to design a simple device at this point, so thanks for any help! :D

-Mintigo
 
  • #62
I don't know about the Doctor's current screwdriver with 29 computers built into it, but his earlier designs were as simple as they can come; Electronics 101 kind of stuff-- 2 easy to get IC chips (XR2206 function generator and CD4046 PPL chip) and a handful of small parts, basically. The design doesn't include the battery converter, which I consider a separate system.

1. The XR2206 generates a variable frequency sine wave and requires 3 resistors, a capacitor, and a pot.

2. CD4046 configured as a VCO (voltage-controlled oscillator) needs two caps, a resistor, and a pot. This is really simple.

3. A resistor connects the sine wave oscillator to the VCO; a couple of resistors connect a pair of transistors and a [miniature] transformer in a push-pull amplifier to drive a ceramic transducer. It's really harder to describe than it is to build.

I had designed the entire screwdriver using Turbo-CAD, an inexpensive but sophisticated CAD package. But when my laptop crashed, all of my files went with it. Fortunately I had paper printouts for machinists to make the outer casing, which isn't simple at all. I had taken drafting and machine shop in high school, but I don't have the kind of machine lathe to cut out the separate parts of the casing

The Romana-screwdriver is nothing more than a 15 kHz power oscillator. It works, but it lacks the style and elegance of the Doctor's screwdriver. :-)

'Doc
 
  • #63
Hi Doc! :)

Thanks for your prompt response. I actually like the previous sonic screwdriver models, as apposed to the current one. And if I am to create one, I would base it off the previous model.

So, to build the screwdriver - I would just require all of the components you've listed above? And then I just piece it all together?

Thanks again!
 
  • #64
It's really a pity that I lost all of my design files. I could probably design it over again from scratch, but that probably wouldn't help you a lot.

But here are a few tips:

The basic XR2206 circuit is very hard to find these days, but here it is--

http://users.ece.gatech.edu/~lanterma/sdiy/datasheets/vco/radioshack_2206spec.pdf

The sine circuit is found at fig. 8 and most of the values aren't critical. The main frequency cap should be 1 UF, while the large cap across the grounded resistor needs to be 22 uF. There's a pot in the diagram to determine amplitude, but I *think* I used a
15K resistor for that. The only pot used is the one that controls the frequency from 1 Hz to 100 Hz or thereabouts.

There's a resistor that controls the shape of the sine wave across pins 13 & 14: I think I used 150 ohms, but that's to personal taste and isn't critical either.

The 4046 VCO circuit is even easier. Unfortunately, I don't remember the vaules I used for it. A resistor and a cap at pin 9 (the other end to ground) in parallel determine how slow or fast the main 15 kHz tone shifts. If you use something like 1M/10 uf, it creates almost a slow siren-like sound; well, it would if you could hear 15 kHz, heh heh. Uh, anyway this is part preference, part practicality: at faster cycling speeds, the faster screws can turn so this has to be ballanced out through experiementation. I can't remember the values I picked.

The CD4046--


http://focus.ti.com/lit/ds/schs043b/schs043b.pdf

-- does need a 0.001 uF cap at pins 6 & 7 to get 15 kHz but this is an easy frequency as the VCO can work as high as 1 MHz. Sound that high can't even travel through air more than a few inches before-- well, let's just say it can't travel through air very far. But at 15 kHz, that's not a problem. I think there's a resistor from pin 11 to ground to control the base frequency, ut it has been a long while since I made this circuit.

Lastly, output put the 2206 at pin 3 goes via a resistor to pin 9 of the 4046 so the 15 kHz square wave is modulated by the 1 to 100 Hz sine wave. The output of the 4046 from pins 2 &3 go via 2.2k resistors into a pair of power transistors, simple push-pull kind of arrangement (I think that's what I did), into whatever miniature audio transformer you can get-- especially if it has a good turns ratio. And the screws go round and round... :-)

I suppose if you are just learning electronics-- or don't know any at all-- this is moderately difficult. The main matter like I said before, is wiring it all together so the circuit is tight and fits inside an aluminum tube, not a square box which would be normal for such a circuit.

But it's murder for me to try and rebuild the circuit from memory. This is the reason for always keeping backup files, sigh...

'Doc
 
  • #65
Oh, yeah: I used the XR2206 because a sine wave gives a nice, smooth, modulation but other wave shapes can be used. A LM555 could be used instead to give a sawtooth modulation that sounds real freaky.

It sounds kinda cool, as such things go, but a sawtooth wave has harmonics (sine waves don't) and those harmonics might cause a conflict that makes the screwdriver inefficient. Same for square wave modulation. It also sounds awful. Unfortunately there aren't any easier ways to get a sine way other than the function generator chips like the 2206 or the MAX8038.

'Doc
 
  • #66
It sounds kinda cool, as such things go, but a sawtooth wave has harmonics (sine waves don't) and those harmonics might cause a conflict that makes the screwdriver inefficient.
 
  • #67
The Doctor and Romana weren't the only ones to have waay cool sonic devices; dig up a copy of the Flint movies from the 60s. Super spy Derek Flint had a sonic belt buckle that he used to first blow up a pool ball, and later used it to escape from a freezing chamber. I think the movie was In Like Flint, staring the late great James Coburn.

Flint's device is a bit more complicated: it produced a series of tones in brief steps-- 100Hz, 300 Hz, 500 Hz, 800 Hz, etc. The transducer looks like a miniature tuning fork, and when he plugged it in the socket, it activated the unit. A really clever design but probably a lot of work for someone heh heh... ;-)

'Doc
 
  • #68
Hey, I came across a box of Screwdriver parts. Most of them stock items-- resistors,
ICs, etc. But here's something I forgot: to help reduce space, I used some exotic bullet
caps I bought from Mouser #74-173D25V10. The stock number means a 10 uF, 25V tantalum cap made by Vishay/Sprague. I used these bullet caps because they are small and compact; easy to fit into a cylindrical casing without sticking up or anything.

They fit between the three resistors needed for the XR2206 circuit or can fit along side of the resistors but either way, these bullet caps are a clever way to make the circuitry compact short of using surface mount parts. But hey, feel free to use whatever parts or methods you want; this arrangement has just worked pretty well for me. ;-)

The only thing left to ponder over is the transducer. I knocked onetogether from some 0.500" dia. piezo ceramic disks I bought from somewhere. The disks are incredibly thin-- they have to be-- and are bonded to a slightly larger brass disk. This is the way standard piezo buzzers are made, only commercial units are made much more neatly. I don't know the resonant frequency as each transducer has an infinite number of variables so it's just easier to make make them and hope they work. By the way, a special electrically conductive adhesive/glue is needed between disks.

Commercial elements can be used, if ones can be found ssmall enough. They do make a 12 kHz element, or at least they used to. This, I guess is all I can say except for,
good luck folks.

'Doc
 
  • #69
That sounds real cool. Hey Doc... I've sent you a PM, please respond as soon as you can, thanks! :D
 
  • #70
I just got the new Doctor Who DVDs and saw the Doctor's brand new sonic screwdriver. It does just about everything but make coffee-- or I suppose because they're British, it does everything but make tea.

There's a book, Father Time, where the 8th Doctor who's stranded on Earth and with no memory of his origins, has made a sonic suitcase; '80s tecnology in action... I suppose you could probably get a coffee maker in that. :-)

'Doc
 
  • #71
Doc Orion said:
Hi;

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

Can someone please try this one again and get video? If Doc said he got it working, then at least there's hope that it's not purely theoretical...

by the way just thought I should add an article about it: http://www.smh.com.au/world/science...r-a-new-twist-for-science-20101205-18lfb.html
 
  • #72
I don't have the things to do it any more; time has passed on. However, if anyone else wants to do it or is equiped, here's the things that you must have to repeat those early experiments:

1. A piezo speaker box with screws at the back.

I used to get those from Radio Shack. Years ago they were cheap and readily available. I'd buy them and gut them for the piezo speaker element inside, then usually throw away the box except for one I kept for experimenting.

If you can find a similar box, good. But sound waves won't turn wood screws (a real screwdriver has trouble turning wood screws) so you need screws that wil turn easily;
say those on the back of some old woofers, etc.

2. A variable frequency audio sound source.

It should be capable of runing from 0 Hz up to at
least 15 kHz. And preferably, it should be nice clean sine waves; you can use a squarewave
source like a 555 oscillator but because it produces harmonics, things may not go too well.

I used a simple XR2206 circuit in sine wave mode, but I suppose any good electronics or
acoustics lab should have an audio frequency/ function generator sitting around or a kit might be available from some of these electronics places that sell educational kits.


3. A good amplifier connected to a step-up transformer.

The output from the audio generator gets amplified; it's voltage stepped up by the transformer-- 8ohm : 1K is a standard transformer and easy enough to find. Or at least it used to be back in those hobby friendly days. Check Mouser or other suppliers.

4. A piezo buzzer

A piezo buzzer is not a very good speaker, but it will work pretty well in this case because the step-up xformer will make it extremely LOUD. At the resonance frequency of the buzzer,
it can get as loud as 140 to 143 dB some 2" from the buzzer. Also, since there is a small
hole in the buzzer, the sound is somewhat concentrated.

BUT... you can do without the xformer and piezo element if you connect the amplifier directly to a bigg woofer; say 8" or larger. Set the top of the piezo box directly on the speaker cone. Use the standard 8 ohm speaker. Connect it to the amplifier with standard speaker wire or
a shielded cable with an audio plug on one end and a pair of aligator clips on the other.

NOTE: if you use the woofer method, the screws will turn themselves downward but not
upwards. That is, turn the screws up to their stops and the sound at the right resonant frequency will make them turn downwards until they can't go any further. But because this
is considerably more inefficient than using the piezo speaker, a woofer can't produce enough vibration at the "anti-resonance" frequency to make the screws turn upward against the pull of gravity-- for that you need sound at very great intensities and only a piezo speaker can produce sound that loud.

And, Oh, use ear protectors: sound that loud can hurt the ears and give you one hell of a headache.

Here's a lesson from "Acoustics 101:" the resonant frequency of an object depends upon such factors as its size and mass. This is why the resonat frequency of a wine glass is much higher than that of a bridge. A good example is to take a crystal goblet (a wine glass will do but it will be trickier) and feed the sound from the loud speaker and adjust the frequency upwards until resonance; at that point, the goblet will shatter violently. Only sine waves can be used for that experiment.

Good luck-- :-)

'Doc
 
  • #73
Doc Orion said:
I don't have the things to do it any more; time has passed on. However, if anyone else wants to do it or is equipped, here's the things that you must have to repeat those early experiments:

1. A piezo speaker box with screws at the back.
...
2. A variable frequency audio sound source.
...
3. A good amplifier connected to a step-up transformer.
...
4. A piezo buzzer
...
NOTE: if you use the woofer method, the screws will turn themselves downward but not
upwards.
...
And, Oh, use ear protectors: sound that loud can hurt the ears and give you one hell of a headache.
...
Good luck-- :-)

'Doc

Thank you so much! With a list that clear, I really have no excuse not to try building one! (Other than... having no experience in building stuff... but I'll get there :-p)
If I ever get one working I'll be sure to post pics and vids here.

Thanks again very much for replying, Doc; you're a legend!
 
  • #74
Me? Nah... I could never get my screwdriver to work quite right; a problem with the switch. Check out the video of the screwdriver prop--


http://www.youtube.com/watch?v=UXGdSGGvhQY&feature=related

Now that guy's screwdriver is beautiful! Too bad the only thing it does is makes noise. But I guess it's sonic after all... <g>

'Doc
 
  • #75
Doc Orion said:
...

Now that guy's screwdriver is beautiful! Too bad the only thing it does is makes noise. But I guess it's sonic after all...

'Doc

Pah, the aim is to get a *working* screwdriver; one that can remove or put in (probably mostly removing :P) screws using sound and not contact.
Even if yours didn't look like the Doctor's (or perhaps *especially*, for creativity's sake) I'd want it waaaay more xD
 
  • #76
Okay...

I was going to keep this secret until 2022, but doing some much needed cleaning I stumbled across a binder with 95% of the working drawings for the Screwdriver. It's unfortunately missing two things: the drawings for the sound-head, and the bottom end cap/ frequency control knob.

Before anyone starts to salivate uncontrollably, let me make this point clear: I no longer have the original CAD files, and I have no way to transmit these files electronically. For some unexplained reason, every scanner I have ever bought has broken down and stopped working within three days after I buy them. My fax machine didn't last too much longer.

SO, if anyone really wants the working plans-- the circuit diagrams for both the
Doctor-screwdriver and the Romana-screwdriver as well as the machinist drawings for the main pasrts of the Screwdiver-- first, send me an email and I will give you my address. Then you can send me a 8" x 10" SASE and as soon as it warms up here, I'll go to Kinko's and have copies made of the plans. From there, children, you are on your own; this homeboy has too many other projects to juggle. ;-)

'Doc
 
  • #77
For those a ittle too lazy to do it physically, here's an idea: get a copy of the Cool Edit program. This does a lot of things with sound-- for example, it can be set to generate a sine wave of a given frequency and modulate it with another to get the sound the Doctor's Screwdriver makes or the sound european sirens make, whatever...

Cool Edit can be gotten for free-- so it's very cheap for those on a bdget. Get the program, learn to use it, and feed the signal from your sound card into an amplifier and a good hi-fidelity speaker. See what kind of amazing things you can do. <g>

But being software, it doesn't have the versatility a real circuit has, yet it has potential. I should point out though, that the first couple versions of Cool Edit while free, doesn't
allow the use of all of the features at the same time but that's okay; most don't need
every feature at once anyway. ;-)

'Doc
 
  • #78
When I first started out I had a number of engineering directories which had some amazing items listed that weren't your usual consummer products. It's been a long time but they are still around, a 12 kHz piezo transducer that's not quite perfect for the Screwdriver, but very close to it.

http://parts.digikey.com/1/parts/485-buzzer-piezo-element-12khz-13mm-kbs-13da-12a.html

I chose 13 - 15 kHz for the Screwdriver's operating frequency because most people can't hear that high-- and I don't care what the books say: damn few people can hear up to 20 kHz. So some textbooks on sonics consider ultrasound starting at 13 kHz and it's a good compromise since acoustical power goes down as frequency goes up. You want to be able to use the Screwdriver at 4:00 in the morning and not wake the neighbors, so use lower ultrasound and even 12 kHz is on the edge of audibility for a lot of people.

Romana's screwdriver uses "pure" ultrasound so high, it's not even audible when working. The design is a lot simpler, but it gets harder and harder to find a transducer for say 18 kHz. There's a company called APC


http://www.americanpiezo.com/products_services/disc_benders.html


who might make custom transducers for a small fortune, but some enterprising person could make them fairly easily from a few really thin 1/2" dia. peizo discs, a 5/8" dia. (or slightly larger) brass disk, and some electrically conductive glue to bond the piezo disk to the brass. Some experimenting with the thickness of the brass would probably sooner or later get you a "bender" that will be resonant at 13 kHz then you really will have some acoustic power! That 12 kHz commercial transducer's problem is that it's kinda small at
1/2" around-- the sound head should be at least 5/8" dia to 3/4" around; the larger the transducer, the more power it puts out.

Of course you can always use a cheap plastic piezo buzzer from Radio Shack, but it won't look that good heh heh. ;-)

'Doc
 
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  • #79
Doc Orion said:
I don't have the things to do it any more; time has passed on. However, if anyone else wants to do it or is equiped, here's the things that you must have to repeat those early experiments:

1. A piezo speaker box with screws at the back.

I used to get those from Radio Shack. Years ago they were cheap and readily available. I'd buy them and gut them for the piezo speaker element inside, then usually throw away the box except for one I kept for experimenting.

If you can find a similar box, good. But sound waves won't turn wood screws (a real screwdriver has trouble turning wood screws) so you need screws that wil turn easily;
say those on the back of some old woofers, etc.

2. A variable frequency audio sound source.

It should be capable of runing from 0 Hz up to at
least 15 kHz. And preferably, it should be nice clean sine waves; you can use a squarewave
source like a 555 oscillator but because it produces harmonics, things may not go too well.

I used a simple XR2206 circuit in sine wave mode, but I suppose any good electronics or
acoustics lab should have an audio frequency/ function generator sitting around or a kit might be available from some of these electronics places that sell educational kits.3. A good amplifier connected to a step-up transformer.

The output from the audio generator gets amplified; it's voltage stepped up by the transformer-- 8ohm : 1K is a standard transformer and easy enough to find. Or at least it used to be back in those hobby friendly days. Check Mouser or other suppliers.

4. A piezo buzzer

A piezo buzzer is not a very good speaker, but it will work pretty well in this case because the step-up xformer will make it extremely LOUD. At the resonance frequency of the buzzer,
it can get as loud as 140 to 143 dB some 2" from the buzzer. Also, since there is a small
hole in the buzzer, the sound is somewhat concentrated.

Good luck-- :-)

'Doc

Could you please give me the sizes for all the components?
and are all of those components used for just the SS?
 
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  • #80
Doc Orion said:
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

Didn't you take pictures of the SS when you had it? or a video? if you did I'm sure everyone here would like to see.
 
  • #81
The finished circuit board for the screwdriver is roughly 6" x 1/2" -- this is just a hand wired piece of perf board where all the miniature components are either soldered directly to each other or connected by a few pieces of 24 gauge or thinner hook-up wire. Somebody more experienced in electronics could probably reduce that size down quite a bit further by using a printed circuit board with surface mount parts, but I was just too lazy to do that kind of detailed work.

However, just to do experimental work in sonics, size doesn't really matter when it comes to parts. Any amplifier, speaker, or audio generator will work as well as the next. The only part whre size is critical is the transducer-- the sound head. That has to be built so as to put out
about 140 dB and still be no larger than say 3/4" in diameter. That's a custom piece of work that's immensely tricky to make as two piezo disks have to be bonded together where the
polarity of each face is opposing to that of the other then connected to a diaphragm The whole thing must then be placed in the retaining ring; a time-consuming and intricate little job. All the rest is just machine shop kind of stuff.

* * *

It's been over four or five years since I had finished the screwdriver-- a long time before YouTube came along, so there ar no photos. 'Was no need for any, and nobody believed the screwdriver could be made anyway. Most people still don't think it can actually be done, but
a little knowledge of sonics & acoustics... is what most people lack, heh heh. Well, it doesn't matter.

I may put a picture of the new circuit board up here in a week or two; if I have the time. It's not the same as the original as I couldn't quite find some of the original parts and I made a
change in the output transistors, replacing the flat 220-type power transistors for 5 watt
metal can transistors... mostly because they look cool. :cool: They probably won't give any more acoustical power then the original flat power transistors but it might be fun to see how well the design works.

'Doc
 
  • #82
Oh my! :OO :FF

I just stumbled upon this tread randomly from google! and as I've been a member of physicsforums for some time now, I don't believe I've ever sat down and read one as thoroughly as this one! it's simply fascinating! I'm going to build one of these within the next year for sure! :D

Doc, you are amazing! :D love the hard work! ^_^ and same to everyone else! =)
 
  • #83
Hey Doc is it possible to get a schematic of the circuit board and a parts list with all the sound ranges that needed be needed for your Sonic Screwdriver. Or as I like to call it a Frictionless Screwdriver.
 
  • #84
zzzspawn said:
Oh my! :OO :FF

I just stumbled upon this tread randomly from google! and as I've been a member of physicsforums for some time now, I don't believe I've ever sat down and read one as thoroughly as this one! it's simply fascinating! I'm going to build one of these within the next year for sure! :D

Doc, you are amazing! :D love the hard work! ^_^ and same to everyone else! =)

I have to say that while it's the best I can do, it is a bit crude. But unless one has access to Time Lord technology, it's hard to get sophisticated ciruitry to fit into a sleder tube.

Since the orignial device, it has occurred to me that I could probably get more acoustical power from a better transformer. I used a standard Radio Shack xformer because 1) they're cheap and 2) they work okay. But if I had been a smarter fellow I would have made a special 'former that was round instead of square and with a higher turns ratio. The standard RS transformer was 1K: 8 ohms bcause you can get those anywhere-- at any Radio Shack or places like Mouser for a few bucks. I used to know the turns ratio but these days I've forgotten it, but I know it's not high.

A 'formr with say a 50:1 or even 100 :1 would put out a lot more voltage-- and more voltage means more power from the piezo ceramic. The only thing is that standard piezo discs are not made for very high voltages; maybe 60 volts max! Too much voltage and the ceramic cracks before you can blink an eye. But you need more voltage to get more sound power. Might be a Catch-22 situation *but* some ceramic companies make high power ceramics such as PZT-8 that can take a higher voltage without cracking. Now here's the catch (and there's always a ctach): PZT-8 doesn't work as well as PZT-5A, the ceramic used in standard piezo beepers, speakers, etc on a volt-to-volt basis. But the PZT-8 can take higher voltages so it kinda becomes a trade-off: you would need a lot more voltage to get the amount of power gotten from driving PZT-5A, but 5A will crack when driven from excessive voltages. Still, it *is* more power, but it might make the Screwdrivr a litle bit bigger using a round transformer.

Something to think about. ;-)

'Doc
 
  • #85
ajs84 said:
Hey Doc is it possible to get a schematic of the circuit board and a parts list with all the sound ranges that needed be needed for your Sonic Screwdriver. Or as I like to call it a Frictionless Screwdriver.

I was lucky: by accident, I found the hard copy for most of my Screwdriver files. I even offered to copy them for a few folks-- all I asked for was a SASE (self-addressed stamped envelope), but what I got was people who wasted my time. As Scotty once said, "Fool me once, shame on you. Fool me, shame on me."

Short answer, these days I don't offer to make copies any more. 'Sorry.

'Doc
 
  • #86
Doc Orion said:
I was lucky: by accident, I found the hard copy for most of my Screwdriver files. I even offered to copy them for a few folks-- all I asked for was a SASE (self-addressed stamped envelope), but what I got was people who wasted my time. As Scotty once said, "Fool me once, shame on you. Fool me, shame on me."

Short answer, these days I don't offer to make copies any more. 'Sorry.

'Doc

Would you be able to upload pics of the sonic circuit board and a parts list?
I really want to build one.
 
  • #87
I totally agree I have been pondering and pondering how when I finish building this how cool it will look plus when I pull it out at a job and people ask what is that? I'll be like it's my Sonic Screwdriver :P
 
  • #88
I'm building a casing for a sonic and I really need a brain for it (ie. the schematics/parts list)
It'll be a mix of Tennant and Smith screwdriver
:)
 
  • #89
acron said:
Would you be able to upload pics of the sonic circuit board and a parts list?
I really want to build one.

My life is extremely complicated right now so I don't know when-- or if-- I'll be able to do
any kind of photos but here's the parts list except for the power converter. It's the best
I can do for now.

Basic Sonic Screwdriver Circuit

B1 9v battery
IC! XR2206 function generator IC
IC2 CD4046 phase lock loop

C1 10uF tantalum cap
C2 22uF tantalum [bullet] cap
C3 .00F uf paper cap
C4 10 uF tantalum cap

Q1,Q2 2N3053 NPN power transistors

R1, R2 5.6K, 1/8 w (or smaller)
R3 15K, 1/8w
R4 150 ohm, 1/8 w
R5 100K miniature pot
R6, R7 2.2K, 1/4w
R8 22 Meg, 1/4w
R9 1K, 1/8w
R10 ? select value to get desired sweep frequency range (13 kHz to 15 kHz)

T1 8ohm: 1K CT miniature audio transformer (Radio Shack)

Notes: R8 & C4 values can be adjusted to give personal sweep values/sonic screwdriver effect

2. Ti can be a custom round transformer with an "I" core and a special turns ratio to get
maximum drive voltage to the piezo elements. Anything from 20:1 to 100:1 step-up ratios
can work well. One might be able to gut a taser for the step-up xformer.

3. The Screwdriver is basically three parts: 1) the XR2206 sine wave generator adjusted
from 0 Hz to 100 Hz or thereabouts-- nothing critical. 2) The 4046 is a simple voltage controlled oscillator with R8/C4 chosen to give a variable sweep delay. These two parts are connected to pin 9 and the other end to ground. The signal from pin 2 of the XR2206 is sent
into pin 9 by way of the 1K resistor. And 3) Very simple push-pull amplifier composed of two NPN power transistors with 2.2k base resistors and transformer connected to each collector
(emitters to ground). The 4046 can produce two out of phase outputs so one transistor is on while the other is off. There are better ways to do this-- such as amplifier chips-- but
all of this can be uilt on a narrow strip of perf-board and crammed into a small aluminun tube pretty easily.

'Doc
 
  • #90
acron said:
I'm building a casing for a sonic and I really need a brain for it (ie. the schematics/parts list)
It'll be a mix of Tennant and Smith screwdriver
:)

That screwdriver does everyting but make coffee! Mine only turns screws-- and the occasional dinner plates... :-)

'Doc
 
  • #91
Doc Orion said:
That screwdriver does everyting but make coffee! Mine only turns screws-- and the occasional dinner plates... :-)

'Doc

Do you have a circuit layout or schematic of how everything goes together?
 
  • #92
acron said:
Do you have a circuit layout or schematic of how everything goes together?


Start with the XR2206 sub-circuit:

http://www.google.com/imgres?imgurl...&sa=X&ei=2wwoTqnRAdKDsAKg-a07&ved=0CFYQ9QEwCA

or just Google "XR2206 circuits" to get the thre images for XR2206 circuits. The third circuit is the basic sine wave generator but there's a couple of differences in the screwdriver--
replace that .01uf cap with a 10 uF tantaum cap (even a 1 uF tantalum cap will do) and that 200 ohm resistor will be 150 ohms. Lastly replace that 50K pot on pin 3 with a 15K resistor. As I say, with this circuit, nothing is critical but you want to get a nice sine wave from 0 to 100 Hz. This circuit is actually a lot more simple than it looks; it took me about 20 minutes or less to knock it together.

Keep in mind, all of these sub-circuits will join together on a narrow piece of perf-board about 1/4" wide--- that's standard Radio Shack perf-board, four holes across-- so it takes some creative wiring to make all the parts fit; they will fit though. The three resistors are mounted behind the 2206 while the main cap (19uF tantalum) and th 150 ohm resistors are
mounted directly on top of the XR2206. The pot that controls the frequency is of course connected by wires and go to the back end of the screwdriver so the modulation frequency can be controlled manually. And since there'sonly room for on pot, that's the only one.

I might replace that pot with a rotary switch and fixed values but you may never know
if you might need a particularly frequency you don't have, so that pot provides flexibility ven if it's a bit awkward to tune all the time.

'Doc


Stay tuned for the 4046 VCO sub-circuit, no pun intended heh heh...
 
  • #93
I'm going to give the link to the VCO, then go to bed; it's now 5:00 am so it's past my nappy time.

The VCO circuit can be found here:

http://books.google.com/books?id=ST...resnum=10&ved=0CHEQ6AEwCQ#v=onepage&q&f=false

The siren ciruit is the one I use in the screwdriver but instead of gating it with a square wave, the circuit is modulated with a sine wave. At pin 9 and the other end to ground I use two large value parts that can be adjusted for personal taste such as 22Meg and 10uF or 15 Meg and 1 uF, etc. These parts determine how fast-- or how slow-- the screwdriver will sweep from one end of the frequency range to another. The frequency cap used is .001 uF so the VCO will work in the near ultrasound. I lost my notes so one will have to pop in resistor values to get it to work no higher than 20 kHz and probably less at 15 kHz upper limit. The screwdriver will however work extremely well at lower audible frequencies producing as much as 143 dB (but we always try for more) of sound, and this will make family & friends hate you as well as upset nearby neighbors so keep the frequencies above 12 kHz-- most humans can't hear that high anyways. But sound of such intensity can cause pain, headaches, and deafness with continued exposure even at ultrasound frequencies.

same as with the first part: the .001 cap on top of the 4046 but the frequncy resistor & cap are mounted in front. The 1K resistor that connects from pin 2 of the XR2206 to pin 9 of the CD4046 is wired below the two ICs on the bottom of the circuit board but make sure the wire is protected with tape or heat shrink tubing so the wires won't short any of the IC pins. That could ruin a lot of nice work very quickly. Still, feel free to experiment with the values; each screwdriver always needs some tweaking for proper operation.


'Doc
 
  • #94
I can't find a schematic for the last sub-circuit but it is one of the easiest push-pull amplifiers:

1. One 2. 2K resistor goes from CD4046 output pin 2 to the base of Q1. The other 2.2K resistor goes from output pins 3 & 4 to the base of Q2.

2. The collector of Q1 is connected to one end of step-up transforner T1 and the collector of Q2 is connected to the other side of T1. The center tap of T1 is connected to the positive (+ 9v) rail.

3. Both emitters go to ground.

Or at least I am reasonably sure how that goes; I don't know where my files and notes
went to. There aren't a whole ot of ways the collectors can be wired or the 'former connected to the power rails so yeah, the primary of T1 shoud likely be center-tapped.

So the basic screwdriver is the sine wave generator-- the VCO-- and the power amplifier. Not a very complicated affair but it all has to fit on a 5 x 1/2 inch perf board (I made a mistake earlier; I meant 1/2 inch).

This doesn't include the power converter which is another beast all-together. That converter boosts a single 1.25 volt nicad battery up to 9 volts. The converter allows the screwdriver to be pocket-sized, running on a single sub-c nicad cell (or two) instead of a standard rectangular 9 volt battery.

'Doc
 
  • #95
Is it possible for you to draw this info up and post it. As I can't see it in my mind even if you draw it on a cocktail napkin as long as we can see it.
 
  • #96
Considring all the mayhem that's going on in my life right now you are really lucky I managed to take the time to lay the screwdriver out in sections like this.
 
  • #97
Thanks for doing this Doc
 
  • #98
hey brennanshaw would it be possible for a diagram and stuff and since I am only a beginner in science would you be able to describe the technical terms you use for me please thank you it would be most appretiated :)
 
  • #99
would it be also possible to make a video of how to make one please id rather it be small and compacted as possible and have loads more uses but like i said I am a beginner as in starting college for it in a year or so I am not very advanced but I am good at tinkering hahaha :) if anyone wants to talk to me email me on [e-mail address removed] please all is appretiated :) love to talk to you all about this stuff and learn much much more than i am going to learn :)
 
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  • #100
@ qbit, I commend, appreciate and applaud that and how you have presented your reports, findings, methods, even the details of the materials used. The fact that you have also added your personal reviews/opinions to them is great especially where you said it would be difficult to use on wood and I would like to point out the many times in Doctor Who, the Doctor has stated and repeated "It doesn't work on wood" and what you have stated could be that very reason. The reason for the nut/washer "jumping" as you said and moving as described would be due to the way and direction the vibrations are acting on the screw/bolt and that it would not work well on wood because would has even been used as a vibration dampener in the past. and it could work on metal frames and such because metal can be used to magnify vibration.

An example of the use of differing vibration used to rotate a screw in opposite directions is the magic toy shown in the attached pic. If you have never used one of these, the way it works is you hold the little wood rod with your thumb and fore-finger pressing perpendicular to the ends and rub it along the grooves with your thumb against the main shaft. Alternating your grip so your finger rubs the shaft makes the fan spin in the opposite direction.
 
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