xveitch's blog

Personally I like the look of rocker switches and rotary pots. Toggle switches can be prone to damage. Silde pots, from my own experience, gum up more easily. I think you will also find them more expensive.

 

The 3rd idea will probably look the smartest IMHO. Curved acrylic and wood will look more 2015 than a boxy one colour product with lots of switches. Idea 2 has an 80s Hi-Fi vibe, but you might like the 'retro' look.

 

As for construction consider a metal frame 'chassis' that everything mounts off. If you have to do any heat-sinking of components it will be helpful too.

Again another possible variation for you -

Rocker Switches - Good

Rotary Pots - Good

Hinged Cover - Good - Possibly clear or dark, semi translucent?

Output Sockets - On the top or bottom - makes it easier to surface mount the unit?

Have you though about using a Arduino NANO? You can get a version with a USB interface for around 99p if you order from overseas. Makes it easier for people to program?

 

Good luck with the project.

 

Andrew

Again another possible variation for you -

Rocker Switches - Good

Rotary Pots - Good

Hinged Cover - Good - Possibly clear or dark, semi translucent?

Output Sockets - On the top or bottom - makes it easier to surface mount the unit?

Have you though about using a Arduino NANO? You can get a version with a USB interface for around 99p if you order from overseas. Makes it easier for people to program?

 

Good luck with the project.

 

 

Andrew

Thanks. I'm going to use the PICAXE range because I've used them before and our DT department uses them. The PICAXE range are also easy to program, with flowcharting and standard programming both featured on the programming software.

The semi translucent cover is also an interesting idea.

Xander

I'll be watching this project with interest - not surprising, in view of my electronics / engineering / higher education background.

 

I should, perhaps, mention that I don't have a layout - and I've never used PICs - but I still find it interesting to see what can be done using electronics.

 

 

Turning to your project, I agree that the last design concept (with a flip lid) could look very neat.

 

In some ways, this concept reminds me of the MCB (miniature circuit breaker) boxes which have replaced fuse boxes in a lot of houses. These usually feature banks of individual (and replaceable) breakers, arranged in a logical sequence with a line of labels above or below them - they can be very neat - but, if changes are made, care needs to be taken to keep things tidy.

 

If I were going down this route, I'd probably replace the tab on the flap with a handle - or extended portion of the flap (perhaps folded into a handle) - on the opposite side of the flap to the hinges. This might give users slightly more purchase on the flap when they need to access what's underneath.

 

I'd probably also look at adding magnet strips (self adhesive magnet tape - or possibly "fridge magnet" paper along this outside edge - to hold the flap in place. A further refinement might involve some felt - where the flap rests on the housing - to improve the seal and make closing the thing a bit quieter.

 

 

I don't know if you've seen any audio mixer consoles - with all the channels arranged alongside each other - controls for each channel laid out in exactly the same sequence - and connections via "patchbays" at the back (or somewhere else convenient). A concept like this would work well here.

 

You'd have no trouble finding loads of good images of mixer desks on the internet, using your favourite search engine - somehow, I suspect you might already have done such a search.

 

 

Personally, I like neat design - everything laid out logically - what you've said so far suggests you also like things well laid out.There is, however, a risk in all of this - the risk of "over designing" your project.

 

Certainly, a closed box can look very neat - but it might also turn out to be slightly inflexible. When you - or anyone else - sets this device up for the first time, can you be certain that the lighting design (or even the circuit) has been finalised? Are all the connections added at this one "hit" - or will someone have to return and make changes, perhaps a number of times?

 

If there are loads of changes further along the line, the whole thing might soon start to look very messy if you're not very careful.

 

 

There's another approach to designing electronic projects like this. This uses 2 pieces of acrylic - held a few centimetres apart using bolts and plastic spacer pillars - with the circuit board fixed to the rear piece of acrylic using short spacers. If the assembly needs to be fitted to the layout board (probably a good idea), this can be achieved by bolting the rear sheet of acrylic to the board using more bolts and spacers.

 

The advantage of using this form of enclosure is that you don't need to make holes for wires - which means that you don't end up with loads of unused holes when you make changes.

 

A number of versions of these have been offered commercially over the years - I can remember Elektor (an electronics magazine) offering their take on this idea a few years back:

 

http://www.elektor.com/media/catalog/product/1/0/100500-71c-web.jpg

http://3.bp.blogspot.com/-Y4oAsBDFuo4/UmvbngNIOfI/AAAAAAAACUI/QBB81Roe2MU/s1600/005+%28Small%29.jpg

 

 

Another current example is the "Space Station Modular Enclosure", offered by weeblackbox.com:

 

https://s3.amazonaws.com/ksr/assets/000/354/949/e370fffb2f09113ec24a5e764bc3ca99_large.jpg?1359118419

https://s3.amazonaws.com/ksr/assets/000/354/950/8ed18b729c8b828f21d2e5575b242258_large.jpg?1359118455

https://s3.amazonaws.com/ksr/assets/000/352/218/e7e26491107c59f589d0808708cb64ed_large.jpg?1358981755

https://makewhatever.files.wordpress.com/2013/03/3f1850a853f9e4cbe36c69c864db2991_large.jpg

https://s3.amazonaws.com/ksr/assets/001/140/677/3d7d8080bc1317d3aa7c4505b7786cea_large.jpg?1381708685

https://s3.amazonaws.com/ksr/assets/001/140/681/38f416a627f379fa2025830c90687c7e_large.jpg?1381708691

https://s3.amazonaws.com/ksr/assets/000/386/406/f1f8118e1d31279855f596836c1bf614_large.jpg?1360759178

 

 

I'm sure it goes without saying that you'll make sure that everything is logically laid out on your circuit board. I'm also sure you'll keep the wiring, connections and adjustable components neat and clearly labelled.

 

Here, I've got further thoughts - which might run against the grain:

• What type of connectors will you use to connect the LEDs to the board? You might wish to use screwed terminal blocks - similar to the "choc block" / "Lego brick" strips used for all manner of purposes, but probably soldered to the circuit board. Another possibility might be SIL or DIL connectors - something like modified turned pin IC sockets - with ribbon cable. Whatever connectors and cable you choose, colour coding is a good idea - as is good documentation (which would probably include a clear circuit or wiring diagram, prepared using a drawing package on a computer - I've used Adobe Illustrator for stuff like this, but MS Paint or the drawing "module" of an office package would also be up to the task).
   
• Once you've set things up, how often are you likely to need to alter the settings of potentiometers in your control circuit? I'm not convinced that you need to go to the expense (and space requirements) of panel mounted pots - presets (sometimes called "trimpots" or "trimmers") would probably be more than adequate for this purpose - but they don't need to be multiturn or anything else exotic.

 

Whatever you do with your project, I wish you success with it.

 

All the best,

 

Huw.

Hi All, 

Thanks for all the comments, they are so helpful. 

 

I've just condensed the overall thoughts into a list. 

So toggle switches and slide pots are a bad idea because of reliability issues, with rocker switches and rotary pots being a better solution. Also, it seems that design 3 is the best case idea for this project (I'll mention Huw Griffiths' idea soon), but it would be lifted to a new level by adding a proper handle, magnetic tape for a secure lid, and to add felt to provide a softer end stop.

Huw asked how a user would attach his wiring, I was personally thinking a screw "choc block" style connector due to its ease of use. This leads onto another point, location. I agree that having the connectors on the back is a bad idea, as it restricts the options the user has for mounting and is generally awkward. So where could it fit in? There are two key places with the design currently, either along the left hand side which would be easy to access, but would restrict placing any units to it's left and would not line up with the "control columns", ruining the simple, organised look that I was trying to acheive. The other option is the bottom, which is unobtrusive but also at risk of catching on something and also less easy to access if the unit will be attached vertically. I must add that the design at this point is only a basis to work from, and is definitely not set in stone, so any further ideas are fantastic. 

 

Huw also mentioned another way of designing the product, with two translucent sheets of acrylic held together by nuts and bolts. I like the adaptability of this and how it can easily become a modular system, but for several reasons I am still not sure that this will work for me:

• Visible circuit boards scare people who have weak electronics knowledge! After some research with the owner of my local model shop, he mentioned that his customers either have a fantastic electronics knowledge, or none at all. Of course, those who do have that knowledge are able to build their own lighting control circuit, which will mean that my product has limited attraction to them. Instead I am aiming for modellers (or any other users) who want to learn and improve. Therefore the product can be used manually or programmed to be automated (flowcharts are easy to pick up, and ambitious users can learn some programming language if they want). Also, as the connectors will be screw, the user could buy pre-wired LEDs to fit, or learn to solder some themselves. In a nutshell, I am aiming for a product whose capabilities match the users' knowledge as they learn. 
• I really like the idea that the product will look and feel like a commercial product, and that I can look upon this process as a manufacturer would. I think this would really benefit my learning, especially as I am thinking about going into engineering in the future. 
• And finally, this project is for my GCSE, and therefore the product needs to be complex enough so I can gain my maximum mark. 

Huw also mentioned that having full sized pots may not add to the product much. I think that if the product was aimed entirely at those intending to use the automation feature immediately, then this would make sense. I feel (tell me if I'm wrong!) that some users would enjoy being able to vary the lights to allow them to give a full day to night to day lighting range (like Miniature Wunderland - they were even planning to sell their own light control unit, but unfortunately it didn't get off the ground - http://www.miniatur-wunderland.com/exhibit/technology/lightcontrol/ ) but without having to program the unit.

 

Maybe I'm trying to be all things to all people? After I've reviewed all this information on my Controlled Assessment slide show, I will be further developing the design, so any more ideas are brilliant. 

 

Thanks so much for your help and support, 

Xander

Just to let you know, there is an new entry on my blog of the finished product! Thanks for all the help you have given me. 

Xander