back to article Build your own WORKING Sonic Screwdriver... for a UNDER A FIVER

The Doctor’s sonic screwdriver has become steadily more iconic as the years progressed. Despite disappearing in the middle of the Time Lord’s career, it’s now firmly – not to say commercially – integrated into the Doctor Who canon. So there’s no more to say on the subject, right? Wrong. Earlier this year, the Sonic …


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  1. jai


    i've been anxiously awaiting this article since you first announced the Who-fest :)

  2. NIck Hunn

    The Sonic Screwdriver X-Prize?

    Given that Qualcomm has persuaded the X-Prize foundation to run a $10 million prize competition for someone coming up with a healthcare device similar to the Tricorder, how about lobbying someone like ARM to fund the equivalent Sonic Screwdriver prize?

  3. Anonymous Coward
    Anonymous Coward

    Sex Toys!

    ....provide the obvious source of plastic components for such a contraption!

    1. Destroy All Monsters Silver badge

      Re: Sex Toys!

      These are not toys but SERIOUS TOOLS... SEX TOOLS!

    2. Anonymous Coward
      Anonymous Coward

      Re: Sex Toys!

      A dangerous subject, likely to be banned by El Reg but still it reminds me of a little song,

      An engineer told me before he died

      Harum titty bum, titty bum, titty bum

      An engineer told me before he died

      And I've no reason to believe he lied

      Harum titty bum, titty bum, titty bum.

      Harum, titty bum, etc....

      I will leave it at that for fear of being censored by El Reg but if you have ever played rugby you may know this and it could very well be the template for a sonic screw driver..

  4. Jamie Jones Silver badge
    Thumb Up

    Nice !

    Great article, as always, Bill.

    I love the self-deprecating humour too!

    I thought you'd left El Reg though....

    1. frank ly

      Re: Nice !

      He did leave, but he left in a TARDIS, so it gets complicated.

  5. Miek

    "We also wondered how you could [possible] make one of your own." -- There was no 'corrections' button

    1. Jamie Jones Silver badge

      It's been confusingly moved to the top of the forum page

  6. Inventor of the Marmite Laser Silver badge

    But, but, but

    Does it:

    a) Actually unscrew things?

    b) Blow the living shit out of (in)convenient bits of scenery?

    1. Anonymous Custard

      Re: But, but, but

      And plug awkward plot (and budget) holes?

  7. Simon Harris


    If you want more space for the electronic gubbins, and less for the batteries, CR2s (3V lithium - 27mm x 15.6mm diameter) and CR123As (3V lithium - 34.5mm x 17mm diameter), as used to be used in many a film camera, can come in handy.

    (for reference, an AA battery is 50mm x 14.5mm diameter)

    1. Anonymous Coward

      Re: Batteries.

      You'd be able to get the requisite 9V out of those too by putting a few in series. 3 ought to do it.

      The trade-off here is that the internal resistance will be higher than what you get with AA cells, so not as much current.

  8. Rob Crawford

    The Masters device ?

    Is it just me or should The Masters Tissue Compression Eliminator not be reassigned to Captain Jack as it does look remarkably like a teenagers drawing of cock & balls ?

  9. Anonymous Coward
    Anonymous Coward

    Back in the day

    of the original sonic screwdriver, I don't think the power tool manufacturers had even thought of giving us an electric one yet.

  10. Christian Berger

    The reason why this works for both 9 and 3 volts...

    (This is heavily simplified as most people here probably won't understand the details)

    This detector is built with a field effect transistor. It's a kind of electronically activated switch. Normally it switches based on the voltage at it's "Gate" connector (the one going to the antenna). It switches between the source and drain connectors so current can flow and the LED can light up.

    Now one thing that's important with LEDs is that the amount of current going through it is not to high. Usually this is done with a resistor. However the current a resistor lets through is proportional to the voltage you apply to it. That's why you need larger resistors for higher voltages...

    However field effect transistors have a secondary effect. If you pass to much current through them while "switched on", they will gradually "switch off" so less current goes through it. This kinda causes an equilibrium where the current is limited at a certain value. Apparently with this transistor it happens just in the range that's acceptable with LEDs.

    1. Simon Harris

      Re: The reason why this works for both 9 and 3 volts...

      I've had transistors that switch off when too much current goes through them...

      they're called broken transistors.

  11. Andrew Jones 2

    Well... I've googled and googled and I just can't for the life of me figure out......

    "Somewhat to the surprise of everyone I showed it too, the constructed Sonic Screwdriver works as advertised, the body lights up red when the upper band is touched, and the greed LED can indeed detect the unseen forces of static electricity."

    What is a Greed LED?

    1. Blofeld's Cat

      Greed LED

      I believe it's a term from the financial services world* - as in the expressions: "green is good" and "banking reforms given a green light".

      * A parallel universe version of Earth.

    2. wbeaty


      Avarice-emitting diode?


      Also: closely examine the tricks listed on RSCD Ridiculously Sensitive Charge Detector site. During humid conditions one can turn the LED on and off by scuffing a shoe on carpet ...but on a low-humidity day one can turn the LED on and off by slightly moving just one single toe.

      Prepare to wiggle your toe, then proceed to ask yes/no questions of your activated S.S. (Capt Pike blinks twice for "No.") Show your audience that it lights up when you smirk at it, but refuses to light up no matter how intense others' gurning. Or, detect either high blood-alcohol levels or disguised aliens (where the light turns on as you wave it under certain noses but not others'.) All this under low humidity conditions, because if otherwise, your audience may notice your larger foot-movements against the carpet.

      - author, (See also hand-drawn holograms, $10 infrared goggles, others)

    3. Paratrooping Parrot

      LED used by those who have a blocked dose.

  12. TedF

    Working Sonic Screwdriver - Pozidrive screwdriver with a whistle built in to the handle.


  13. Stuart Halliday

    And what about your project is 'Sonic' or even a 'Screwdriver'? Hmm?

    1. Anonymous Coward
      Anonymous Coward

      Look at mine then! I press this switch and that light comes on.

      Oh, ok... if you must spoil my day, yes, it is just an electric light.

    2. This post has been deleted by its author

  14. Destroy All Monsters Silver badge

    And in the next project I want to see a Lazy Gun.

  15. Anonymous Coward
    Anonymous Coward

    "Somewhat to the surprise of everyone I showed it too, the constructed Sonic Screwdriver works as advertised, the body lights up red when the upper band is touched, and the greed LED can indeed detect the unseen forces of static electricity."

    The greed LED? Have you tested it at a large bank to see if it works?

  16. Mr Flibble

    You want sonic?

    I have a sonic screwdriver.

    tap tap tap

    See? It makes a sound. That's sonic, right?

  17. Anonymous Coward
    Anonymous Coward


    Mine detects:- Radiation (all ionising + wifi and 3G), ELFs, magnetic fields.

    And thats just using an Arduino Uno R3.

    I am working on a neutrino detector for it but the tricky part is making the K40, please can someone help with this? Growing a pure crystal by differential crystallisation using the slighly different melting points of K39 and K40 is going to take aaaaaaages.


  18. Andus McCoatover

    Takes me back awhile....

    When I worked for BT (Post Office then), we got some of those new-fangled FET things. 2N3819. Bloody expensive then - at least a quid, which in the 1970's would have bought a couple of bevvies.

    My boss used to get a fit of the vapours when I'd test 'em by sticking an AVO-8 between source and drain, then comb my hair to watch the needle thrash about. They were J-FET's - no real harm if I was careful

    (Didn't dare try with the much more expensive and fragile 40673 dual-gate IGFET's. Man, you had to be careful not to remove/dislodge the shorting ring 'til they were soldered in place!).

    As to the writer's cct, adding a UJT, a cap., resistor and a piezo loudspeaker - THEREMIN!!

  19. Crisp

    Sonic Screwdriver? Who uses those any more?

    I want to see El Reg's article on building your own laser screwdriver!

  20. All names Taken
    Paris Hilton

    Mate, its just a story. It ain't real.

    The doctor is an actor.

    One of the last doctor's is now advertising stuff for Virgin and I bet if he used his sonic screwdriver or its series X derivative in the ads the BBC would probably sue for some contractual breach or infringement of the commercial (cashcow?) entity that is/was/never will be Doctor Who?

  21. lawndart


    But the real question is "Is Matt Smith enjoying his Squid-on-a-Stick?"

  22. Alister

    "Eddies in the space-time continuum"

    Is he? How nice...

    1. Destroy All Monsters Silver badge

      Crazy Eddy!

  23. Anonymous Coward
    Anonymous Coward

    Eddi in space

    I refute the above allegation


  24. Steve Martins

    How do they fit all that functionality in?

    My money is on the hypothesis that the screwdriver is bigger on the inside...

  25. Stevie

    Bah! have invented a device that can detect someone combing their hair less than 5m away?

    I have two of those already. I call them "eyes". As it happens, they will also detect the same mysterious force if the target combs their hair in the dark. Because of all the sparks.


  26. Wzrd1 Silver badge

    "This was important: shoehorning a box-type battery into the shape of a Sonic Screwdriver would challenge even the designers of the Tardis."

    Fair enough. A rather similar job was quite handily dispatched by the Apollo 13 ground team.

  27. Anonymous Coward
    Anonymous Coward


    I might accept that challenge.

    Making a Tesla Coil screwdriver would be possible, came up with a design based on a magnifier setup using piezoelectric transformers harvested from dead flat panels and a custom wound double resonant secondary with a pair of antiparallel windings.

    Also you can now get <300nm burner diodes which will allow air ionisation so the spark follows a well defined line from the device.

    They are a little expensive though.

    (also why the thumb down?)

  28. The Indomitable Gall

    Deus IN machina! Deus IN machina!

    The sonic screwdriver is not deus ex machina at all, it is deus in machina. Deus ex machina requires a previously unmentioned outside force to affect the course of events, but the sonic screwdriver is an established element of the Doctor Who story universe, therefore it is not an outside force by any stretch of the imagination.

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