Custom LED Sign Board
What I am looking for is to make a rectangle with rounded edges type shape with lighting for a sign. I need flexible lighting that is also waterproof and durable. The rectangle is about 5 feet long and 1 foot wide. What I would ideally like to be able to do is light this sign up and on the back have a small circuit board powered by some common batteries such as double or triple A's. Unless their is another cheap alternative that is widely available. Also I would like to have the option to alternate patterns of the lights, such as chasing, strobe, flashing etc.
Rounded Circuit Board Corners
A standard printed circuit board routing technique can be utilized to produce the rounded edges on the corners of your printed circuit board. This may increase the printed circuit board cost slightly. So if the rounded corners are not absolutely necessary I would not recommend excluding them. Producing a single printed circuit board majoring 5 feet long, would be nearly impossible. Your LED sign board will need to consist of an array of smaller printed circuit boards. Therefore, the circuit boards used for quarter sections would need to be different, so that they can feature your rounded corners. This may be an additional consideration that would ultimately affect costs.
Flexible LED Sign Board
Manufacturing a flexible LED sign board will present a reasonable challenge. It may consist of numerous smaller printed circuit boards light together from connection points. The feature of flexibility would be derived from each connection point, thus allowing each circuit board itself to remain in a fixed position. Rigidity of the PC board is somewhat critical since most standard boards are not really designed to be flexed or bent. Doing so can lead to numerous technical problems, including lifting pads, traces, and popping off components from the surface of the PC board. That interlinking flexible components between circuit boards may consist of ribbon cable, flex PC board material, or some other means providing flexibility between boards. An array of individual interconnected boards would also extend possibility to produce custom size LEDs signboards, as opposed to limit yourself to one single size.
Battery Powered Signboard
Even though the double A and triple A batteries are very common, they may not offer enough capacity to power a 5 foot long LED signboard. The battery size required for your signboard will depend on several factors. One, being the title number of LEDs contained within your LED signboard. It will also depend upon the current draw of the LEDs. Most likely, your signboard will require a much larger battery cell or array of cells. Although LEDs drop much less current than traditional lighting sources, they can still consume a considerable amount of power. An efficient circuit design can also help preserve battery life.
Chasing LEDs on Signboard
To include the special functionality on your signboard, such as chasing, strobe, flashing, or other special patterns, the signboard will require a means to control each LED or LED group. A PIC microcontroller can easily provide this functionality. The microcontroller will consist of a firmware script which dictates the actions of the microcontroller. The firmware, if custom design to provide your signboard with the desired functionality. The primary advantage of this technique is that changes to the firmware can allow you to revise the functionality of your signboard without making physical hardware changes. Updating the firmware requires a person with knowledge in PIC assembly language. The overall functionality of your printed circuit board will be increased. In a simple LED board design, all the LEDs within the array normally draw current from a common power bus. With the addition of advanced functionality the board must now contain a series of data lines interconnecting the microcontroller with individual LED groups. In many cases, especially those consisting of high power LEDs, the microcontroller not sufficiently power each LED or LED group. When this is the case, a secondary electronic component would be required as a buffer between the LED and microcontroller. If your signboard is using low power LEDs, such as the famous 5mm package, then the PIC microcontroller may not have an issue sourcing current directly to the LEDs. On the other hand, if you are using a high power LED such as the Luxeon Rebel, you will certainly require a buffer between the microcontroller and LEDs. Excluding it would damage the internal microcontroller circuitry.