I am currently making a jacket that has a back panel covered in 3mm white LED's which are responding to a proximity sensor. I do not know much about electronics /circuits but have drawn up a circuit which may work? (probably not).
So in the diagram, my version of some kind of schematic, the black line is connected to +5 V and the green to ground. The black rectangles at the start of each row are resistors (100 ohms?) and the circles are 3mm white LED's.
All components will be connected using conductive thread and stitched to fabric.
Basically I want to know if this circuit will work? and if not how I could make it work?
It won't work as drawn. What you need is a true electrical schematic (even if just a single row) to tell if what you are trying to do will work or not.
Also what is not clear is if you want single rows or columns to turn on or off or if every led is able to be turned on or off. You are not showing how you will be controlling turn on and turn off controls, your just showing a voltage source being wired to an array of leds, which may or may not be wired is series or parallel.
So more information is needed to help you in any meaningful way.
Willverity:
If it was to be controlled by Arduino / Lilypad the maximum voltage I could use would be 5v? or is that wrong?
There's no way you can power than many LEDs directly from the pins of an Arduino. You have to power them via an external supply and use the Arduino to switch them.
Does it have to last a long time? Does it need to be worn for long periods? Is it just a one-off for a parade (burning man)? Does it have to fold up small? Get stuffed into a bag...?
Willverity:
And I simply want to for example turn them all on and then all off. Not control individual rows.
Do you actually need an Arduino to do that?
If you get the power directly from the pins you can power at the most two LEDs per pin or four if you run them at half power.
You need to drive a transistor with the pin and use an external power supply to drive the LEDs.
Look at the first circuit on this page and substitute your LED and resistor for the motor:- http://www.thebox.myzen.co.uk/Workshop/Motors_1.html
You can wire several LEDs & resistor pairs in parallel.
Basically i need the arduino because the lights are responding to a proximity sensor, so if an object is closer the lights will respond ect..
fungus - right now it would be great if it could work even for 10-15 minutes, it does not need to fold or anything
the resistance of the thread is 14 ohms per foot I think..
So there is a way to connect the lights directly to a power source, and have the arduino connected to the same power source? While the arduino is still controlling the lights using transistors to up the voltage?
Basically i need the arduino because the lights are responding to a proximity sensor, so if an object is closer the lights will respond ect..
fungus - right now it would be great if it could work even for 10-15 minutes, it does not need to fold or anything
the resistance of the thread is 14 ohms per foot I think..
So there is a way to connect the lights directly to a power source, and have the arduino connected to the same power source? While the arduino is still controlling the lights using transistors to up the voltage?
No, one end is connected to the power source the other end to a transistor or FET. The arduino controls the switching on or off of this device by a connection to the base ( through a resistor ) or the gate ( if it is a FET ).
As for the production side - the use of conductive thread for this many LEDs is fraught with short circuits and will be exceptionally time consuming. I suggest you consider using flexible LED strips such as http://www.superbrightleds.com/cat/flexible-strips-and-bars/
Also check Erik Johnson's project for production ideas.
I'm not sure where the step up voltage regulator would come into this? are you saying that the voltage regulator could come after the MOSFET, pulling up 5V to 12V and mean that I can run everything from the same power source?
There a few things wrong with that diagram.
You do not feed 5V into the power jack you feed between 7V and 12V so the board regulates it down to 5V.
You need to connect the grounds of your two power supplies together or it will not work.
See:- http://www.thebox.myzen.co.uk/Tutorial/Power_Supplies.html
I'm not sure where the step up voltage regulator would come into this?
To replace the 12V supply and drive it from the lower supply. However you can just drive everything from one supply.
That picture is way too big, please read the how to use the forum sticky post.
