electrical help

[pcal]

"inserting the socket with LED attached while the resin is still liquid - quite easy really", ok, I believe you, but how do you connect to the LED?

Imagine if you will... (what it would look like, not how you would do it) take the plug on the end of your ipod headphones, cut off the wire from the plug, and solder the LED back in place of the wire. Now imagine your rubber mold filled with liquid resin, with a headphone plug sized hole in the top. Poke the LED end of the plug into the hole, plunging deep into the heart of the issue (small pun there leaving the metal pin (the bit you normally whack into the ipod) sticking out in the breeze. The resin hardens, the led is stuck on the inside, the plug connections are attached on the outside.

Make up your net separately, but rather than led's, solder sockets into the net at all the places you want a heart to go.

Voila! Plug your heart into the net. (My instinct tells me I should be saying something about anti-virus and filters here, but I'll let it ride this time...)

I thought they where (shuddering) cheap?

"cheap" is a relative term. Compared to gold bullion, blue led's are cheap. Comared to red led's, they're not.


Regards,

Glen

[Harry II]

and solder the LED back in place of the wire.

Please excuse my ignorance but the LEDs I saw on a web sight had two prongs stickn out of a coloured glass looking head, are there 2 wires coming out of an Ipod socket? If so, solder them to each prong, yes?

Make up your net separately, but rather than led's, solder sockets into the net at all the places you want a heart to go.

Voila! Plug your heart into the net. (My instinct tells me I should be saying something about anti-virus and filters here, but I'll let it ride this time...)

it's starting to look like a flat christmas tree:confused: , the hearts will look plugged-in, I'd rather have the wire going through the hearts and preferably cross at the intersection of the light (no religious conentations intended).

"cheap" is a relative term. Compared to gold bullion, blue led's are cheap. Comared to red led's, they're not.

How much are common reds ones?

Thanks for the advice Glen, you certainly have a good mind for figuring things out, albeit in a direction away from my initial concept of which is still cooking. I've even thought of incasing the whole arrangment, which opens up more possibilities inspired by your suggestions, thanks. Thing is I don't like resin much, Ive never really like the look of it let alone the smell but it may have to do, it runs a poor second to glass. Ultimately the hearts wood be glass but people whom I have met (2) who work in glass say it can't be done, let alone having a light inside. Till next time, kind regards.

Harry

[pcal]

As noted, my description was for what it looked like, not how to do it. An actual ipod plug would have three connections (for stereo), but you can buy them with only two - called a "2.5mm mono phone plug", and worth about 50c each from Jaycar in bulk if you take the black plastic ones, or about $1.30 each if you go with the shiny metal ones. (I was in Jaycar today, and noted some of the relevant prices...) Yes, you would solder one pin to one connection on the plug, and the other to the other. As you are looking at a custom application, there would be no standard way of doing it, so it would not matter which way around you did it, so long as they were all the same. The sockets on the net would also have to be wired the same way as each other. Matching sockets were about 65c each for the plastic version. So long as the plugs and sockets were all consistent, you would have a 50/50 chance of them all working first time, and if they didn't, you would only have to reverse the wires coming off whatever power supply you use.

They had red LED's in a packet of 100 for a few dollars (sorry, I can't remember exactly how much it was), but they worked out to only a few cents each. But they didn't stock blue LED's - Had some products with blue led's in them (so they certainly exist), but just not for sale individually at least at Jaycar.

I guess I was looking at the practicalities of how to do what you asked for with off the shelf gear. My background is in fixing electrical, electronic, and mechanical things that break - so when designing stuff, I'm looking for "robust", and "easy to work on".

It may be possible to do it without using plugs and sockets - but if you're going to have wires set directly into the resin, I don't think any sort of copper is going to stand up to the mechanical stresses you are likely to give it. A stainless steel cable of a fine enough gauge may have enough strength, and can also be used to carry the supply for the LED's, but introduces a number of its own problems...

1) It would be a pain to try to solder the led's onto (x 900!) - stainless doesn't solder real well.
2) It would significantly increase the complexity of molding, as you would have to assemble the net first with the LED's in place, then hold the cables somehow so they don't short out while molding the hearts around them...
3) You would have to insulate the cables somehow between hearts so they didn't short out (otherwise, at best - you may get the wrong LED's coming on, or at worst - you could blow up the electronics controlling them.)
4) The resin hearts themselves would become the mechanical tie between the horizontal and vertical strands of your net. If something were to fall onto your net for example, the cable would likely rip your hearts to bits.

Suppose I'll leave the creative to you, just putting in my 10c worth on the practical side.

Regards,

Glen

[Harry II]

More than 10c worth Glen, thanks. I to don't like making things that are likely to fall apart easily, I've always tried to build things that are robust but all the plugs, sockets and soldering is getting too busy, but your right, it's the way to achieve what I asked how to do in terms of the electrical connections to lights. Considering all that, I'm thinking of doing one with a copper net and resin (glass still lingering) hearts and maybe back light it and doing another where the hearts with plugs, sockets and soldering are incased in a resin/fibreglass pane. What are the chances of a LED failing, over what time? I have noticed some are more expensive than others, assuming that you pay for quality, would that decrease that chances of it failing?.
Both the above works can now be considered possible candidates for being able to control sequences of LEDs, is there a good not to technical resource for finding out how to wire such a thing up so I control it?

Kind regards
Harry

[olddog]

Hi Harry,
Just a recap on your project todate I think you are getting some where now with good advice from PCAL and others,what you want to do can be done,BUT at what cost, your project could cost between $100 and $10,000 depending on what way you go and what electronic controls you want switching etc again the net can cost an arm and leg if you want it to be the mechanical and electrical carrier all in one,on the other hand it can be done at a fraction of the cost if you split the mechanical and the electrical,like PCAL said copper work hardens over time so the less stress the better,I think you will have to overlay the net with the electrics on a cost basis and stress wise as well. Connecting the hearts to the wiring is another challenge but can be over come,your project is much bigger than I at first thought and more complex in what you want for an outcome, but dont let that stop you. Ok off on another track I think you need a bit of electical knowlege without getting to complex so may I surgest some of the books obtainable from Dicksmith on the basic,s of electronics not to complex just enough to get you up and running on the terminology. Please PM me with your address and I will drop you a few LED,s and resistors to play with,I have lots laying about that I will never use so you can blow them up for practice and get a bit of soldering practice as well,Good Luck........Peter

[pcal]

Hi again Harry,

Irrespective of whether your light source is in the heart or outside of it, the "work hardening" properties of copper would make it a poor choice in my opinion for your net material - copper is a "soft" metal. You can get stainless steel cable that is still quite flexible, but would take a lot more effort to work harden. - Marine suppliers would be a good place to go to have a look at some...

LED reliability is generally fairly good. They are MUCH less likely to fail than incandescent or fluroescent globes, but failure is still possible. That said, I'm not aware of any other light source that I would consider to be MORE relaible that LED's. If your going to the wholesalers to get the quantity your looking for, they should be able to give you a MTBF rating on the led's from the manufacturer (Mean Time Between Failures). The bigger the number, the better the quality.

I hope I'm not judging your level of electronic understanding too harshly, but based on what you have said already I believe building a computer interfaced de-multiplexor suitable for driving your lighting would be beyond your capabilites. I understand the principles involved, but would probably look for some more experienced help if doing it myself...

I'll try to explain it as simply as I can so at least you will be able to ask the right questions of any electronic techs you contact.

Multiplexing is a process of converting a number of individual inputs, into a code number. De-multiplexing is a process of converting a code number, into one or more of a number of individual outputs. You would need a de-multiplexor. The software in your computer (that would also be custom written for this job) sends a code number down the serial or usb cable to the de-multiplexor, which interprets that code as an instruction to switch on output numbers "X". The output lines from the de-multiplexor switched on by this instruction then drive their transistors (basically electrically controlled switches) which turn on power to their corresponding LEDs.

You would need a "64bit" de-multiplexor - ie one that has 64 output lines. 30 of those lines would control switching the positive power to the x axis lines in your net, 30 more to control switching the negative power to the Y axis lines in your net, and 4 spares. (30 X by 30 Y = 900 hearts, yes? Maybe you could use the spares to trigger special functions, like turn on all leds for a test, or something like that)

Every possible combination of output lines from the de-multiplexor would have a corresponding code number. So your software would choose the code number that turns on the 1st y axis line, and every x axis line in the first y axis line that needs its led on for the current image.
[note: now you would have positive being fed down however many of the x axis lines you wanted on, flowing through (and thereby turning on) the led's you want in the first row, and then flowing out through the negative connected to the first y axis line. There would be power on one side of the corresponding x axis led's in every other row as well, but since the negative is only connected to the first line, all the others stay off.]
Then the computer would send the number that corresponds to the 2nd y axis line, with every x axis line in the 2nd row. Then the 3rd y with corresponding x'es etc. etc. After sending the 30th y axis code, the computer jumps right back to the 1st again.

This would all happen so quickly, that the computer would have sent its codes for all 30 of the y axis lines in less time than it takes for persistence of vision to loose the light from the first y axis row. So it looks to the observer that there is a steady image over the entire net. This process is called "rastorisation" - displaying an image one line at a time, and is basically the same way a television screen operates.

As I said before, theory is one thing - but practice is something altogether different. At least I hope you get a basic idea of how it could work...

Regards,

Glen

[Ashore]

If I remember correctly there are also single LED's with two colours and three prongs that could give you even more variations of colour

[Harry II]

I hope I'm not judging your level of electronic understanding too harshly, but based on what you have said already I believe building a computer interfaced de-multiplexor suitable for driving your lighting would be beyond your capabilites. I understand the principles involved, but would probably look for some more experienced help if doing it myself...

I can't agree more. Are the specialist lighting electricians that would be willing to take on a project like this? I made myself start something else today to stop thinking about it, think I'll leave it settle down a while so I can establish true direction with it.

If I remember correctly there are also single LED's with two colours and three prongs that could give you even more variations of colour

I think I may enough on my plate at the moment for one little bird brain.

Regards,
harry