Sonic Screwdriver Wiring Question

[The14thDr]

I am planning on building another collapsible prop, but this time it is a sonic screwdriver. As part of my fourteenth Doctor persona, I'm planning on building a custom sonic. I want it to fold down like on the Paul McGann sonic (I also believe Teletran did this as well).
But this topic isn't about the collapsing element, this is about a wiring problem. If I were to have a circuit inside the sonic (ie. wires, batteries, buttons and LEDs), how would I tackle the problem of having the sonic open up and close again without snapping the wires or getting everything tangled up? And how would I get inside to change the batteries without having an ugly battery compartment built into the side (for this I'm looking for some inventive ideas)?

Kind regards, The14thDr

[the_prop_maniac]

If you're using battery cells like they do in the Character Options sonics, you could make a stalk out of it, e.g. make a casing for three of them, that'll be the stalk, then you can choose, that if it needs to be electronic, you can either put batteries in, or take them out.

- Tom

[steve757]

All my sonics put the batteries in single file in the grip with a small plug at the end held in by a setscrew.  Easy to change.  As far as wiring on a moving part, multi strand wire will withstand more moving around without fatigue-breaking like single strand wire will.  Another potential solution is to use rechargeable batteries and have two electrically isolated pins on the outside you can clip a charger to.  No need to take it apart to recharge.

[jorwick]

I am planning on building another collapsible prop, but this time it is a sonic screwdriver. As part of my fourteenth Doctor persona, I'm planning on building a custom sonic. I want it to fold down like on the Paul McGann sonic (I also believe Teletran did this as well).
But this topic isn't about the collapsing element, this is about a wiring problem. If I were to have a circuit inside the sonic (ie. wires, batteries, buttons and LEDs), how would I tackle the problem of having the sonic open up and close again without snapping the wires or getting everything tangled up? And how would I get inside to change the batteries without having an ugly battery compartment built into the side (for this I'm looking for some inventive ideas)?

Kind regards, The14thDr

If my fabrication skills were up to it, I  would power the system via a rail-- a long bare section that makes contact no matter what position the concentric tubes are in ( one tue slides over the other making good contact the whole way.. . You Could probably accomplish this with conductive paint.  Of course if you only want it powered in on position, the conductive area can be much smaller - when the two tubes make contact and/or click into place9 Closed or open) .  The batteries would probably be most effectively located  in a the smaller tube that the larger tube slides over, But then you can double up on tubes to that one tube slides into the gap between two tubes..  I think the best way to hide the battery compartment would be to allow the two tubes to separate in the middle, you can then stack the batteries in from the "middle" when the two halves are separated - However it my be even better ( and truer to the show) if you were to use rechargeable batteries and charge it  using a wireless  inductive method..  like many "sonic" toothbrushes are using these days...

[galacticprobe]

As far as wiring on a moving part, multi strand wire will withstand more moving around without fatigue-breaking like single strand wire will.  

That multi-strand wire Steve mentioned is also known as "ribbon cable". Sometimes it comes in a solid color (usually grey) and sometimes in a literal rainbow of color. It's easy to trim down the width of the cable because the wires in it pull apart like the strands of a Twizzler candy. You will have to separate the ends a little to trim away the insulation so you can attach the wires.

However it may be even better (and truer to the show) if you were to use rechargeable batteries and charge it using a wireless inductive method... like many "sonic" toothbrushes are using these days...

They've got mobile phones and hearing aids that charge the same way now, and this is a smashing idea! Unfortunately this would be something that would need some good research into as it's beyond my level of electronics expertise. (If it's broken - radar, TV, satellite communications, etc. - I can fix it; but I'm not an engineer so I can't design anything beyond the most basic, simple circuits... and even then I need a little help from some of my old electronics books.)

Dino.

[jorwick]

As far as wiring on a moving part, multi strand wire will withstand more moving around without fatigue-breaking like single strand wire will.  

.

Yeah, but even  a stranded wire is going to eventually break under repeated movements. I think making the casing perform as a the wire either by being a long exposed strand embedded in the casing, a flat  metal strip embedded or  on the surface of the casing , or conductive paint ( or combination)  will be more durable than repeated folding of a wire..not the mention the possibility of a jam  were the wire gets stuck in the mechanism as it opens and close

C=Casing . + = Positive  - = negative - so as a cross section of the casing you might have something like

ccccccccccccccccccc
+++++++++++++++++ <-- contact point
battery                +++cccccccccccccc
battery                cccccccccccccccccc  <---> inner section slides in and out
battery                 LEDS, CPU, etc.  
battery                cccccccccccccccccc
battery                ----cccccccccccccc
----------------------
ccccccccccccccccccc



That way you ave power no matter if the extension is in or out etc.. You could ave leds in the base or switches etc and increase the number of "rails', but I would keep it to a minimum .. otherwise this gets hard to make without 3D printing it and then inlaying the metal strips etc..  Making the bootom casing flat and rolling it into a cylinder after the fact would also make this somewhat easier.

They've got mobile phones and hearing aids that charge the same way now, and this is a smashing idea! Unfortunately this would be something that would need some good research into as it's beyond my level of electronics expertise. (If it's broken - radar, TV, satellite communications, etc. - I can fix it; but I'm not an engineer so I can't design anything beyond the most basic, simple circuits... and even then I need a little help from some of my old electronics books.)

Yeah, Amazon is selling the open charger boards for around $10 ( the kind iphone etc use)  and the charging circuit on the battery side is pretty simple. ( but yeah, be careful or the battery can actually EXPLODE if you do it wrong) Here is a good overview (http://circuitdiagramcentre.blogspot.com/2012/01/how-to-make-inductive-li-ion-battery.html)  but I would look closely at the actual batts I planned to use and ensure I was staying under the current limits specified.  Some batteries you can only charge so fast and over current/over voltage  will damage and/or cause a dangerous situation.

Looks like Adafruit is selling a couple of off the shelf modules that might be small enough to do  the job..one might need to redo the coils so they are smaller... It would change the inductance somewhat, and that would potentially cause problems with the ICs.but I don't tink they would have to be reduced that much in size. just make them as big as possible.

https://learn.adafruit.com/wireless-inductive-power-night-light/wiring-diagram
https://www.adafruit.com/product/1407




]

[warmcanofcoke]

I got my sonic from a group run Bob Mitsch did a few years back - here is the sound module they used.

[elkad]

[/URL]

Looking at this, their should be a place were you can get a sonic sound module & optional light connection for Custom Sonic Screwdriver prop builders.

There would be two module types. Were the sonic presses on the battery's making the connection, like this one, & the regular button switch for the outside of the sonic.

[galacticprobe]

Yeah, but even  a stranded wire is going to eventually break under repeated movements.

Don't confuse "multi-strand" wire with "ribbon cable"; they are two different animals. Most wires you get on spools for electronics or some electrical work is multi-strand, which is why you have to twist the little strands together before soldering them or connecting them to something. (House mains wiring is "single strand" as each wire is made from only one - albeit thick - strand of wire. You might have three wires in the bundle, the "hot", the "neutral", and the "ground", but each is a single strand.)

A "ribbon cable" is a "multi-wire" cable that is designed for flexing and bending and even twisting. (If you've ever been inside a computer and seen the wide cables connecting the disc drives to the motherboard or drive controller, then you've seen a ribbon cable.) Ribbon cables come in a variety of wire gauges, and widths (number of wires in the cable).

Ribbon cables are used in places where there is going to be a lot of movement and the wires need to flex repeatedly without breaking.

I hope this clears up any confusion in terminology.

Dino.

[jorwick]

Yeah, but even  a stranded wire is going to eventually break under repeated movements.

A "ribbon cable" is a "multi-wire" cable that is designed for flexing and bending and even twisting. (If you've ever been inside a computer and seen the wide cables connecting the disc drives to the motherboard or drive controller, then you've seen a ribbon cable.) Ribbon cables come in a variety of wire gauges, and widths (number of wires in the cable).

Yeah, I understand what you are talking about,  but I suspect that inside a small casing with the throws like the one we are discussing the bend radius of a ribbon cable is likely to be exceeded, and then they eventually fail....

[The14thDr]

Thanks for all the information guys; it's definitely given me a lot to consider when I eventually get round to scratch-building my own sonic.

**WARNING -- Extremely long and question-filled post ahead. Continue with caution.**
I also have another question/request for thoughts, this time for my sonic sunglasses.
I saw an interested thread on the forum where someone was modifying a pair of ordinary sunglasses so that they would have an LED and play sounds.
That got me thinking, and I was wondering if I'd be able to alter one of those recordable sound modules that you can buy online for a couple of pounds.


1. According to the description, the speaker diameter is 4cm, so I was wondering if there was a way to make this smaller (either by rewiring the circuit with a smaller speaker - like the ones in the sonic screwdriver toys, for example - or by another method?)

2. The module also has a second push button and a microphone for recording the sound, so would I be able to remove these once the sonic sunglasses sound has been recorded onto the circuit?

3. The red LED in the picture only turns on when the module is recording, so would it be possible for me to remove this and replace it with a white or blue LED that lights up when the sounds are playing?

4. Is it in any way possible to file down/cut the circuit board down so that it is small enough to fit on the arm of the sunglasses?

Sorry for the enormous post and the multitude of questions; as you can tell I'm clueless when it comes to circuits and stuff. If anyone could help with the questions above I would be very grateful.

Kind regards, The14thDr

[13drwho]

1. According to the description, the speaker diameter is 4​cm, so I was wondering if there was a way to make this smaller (either by rewiring the circuit with a smaller speaker - like the ones in the sonic screwdriver toys, for example - or by another method?) YES. If that is an 8 ohm speaker any 8 ohm speaker that meets the power requirements will work (power is the wattage)

2. The module also has a second push button and a microphone for recording the sound, so would I be able to remove these once the sonic sunglasses sound has been recorded onto the circuit?Yes. you can just clip the wires at the board if you are careful.

3. The red LED in the picture only turns on when the module is recording, so would it be possible for me to remove this and replace it with a white or blue LED that lights up when the sounds are playing? No. That LED is probably coming off of the IC and can't be re-purposed.

4. Is it in any way possible to file down/cut the circuit board down so that it is small enough to fit on the arm of the sunglasses? No. Do not cut or file the board unless you are absolutely certain where all the electrical paths are... even then it is a bad idea. I have done it in the past when I had intimate knowledge of the board and it is still very risky.

[galacticprobe]

As an electronics tech since 1981 I can only echo what The Jason has already said.

As for this...

I also have another question/request for thoughts, this time for my sonic sunglasses.

"No, don't do that. Don't. Don't."

Dino.

[steve757]

most electrical parts houses sell tiny earphone plugs and jacks....2.5mm is about the smallest.  The jack would go in the base of the sonic and connect to the  pos and neg of the batteries, and the plug would be wired to the charger.

[The14thDr]

Thanks once again for the help and advice guys. I may just leave the sunglasses as they are and just carry the sound module around in my pocket, so I can put on the sonic shades and have the sound activate without a circuit or battery in sight. I'll take a look in my nearest electronics shop when I get the chance and see what they have in terms of earphone plugs.

Kind regards, The14thDr

P.S. Maybe I could disguise the sound module as another prop (for instance the Second Doctor's electrical detector, but that's an idea for a different thread.)