This is one of many panels I made for the pilot of a kids show many years ago (2003). Back when the gallium nitride LEDs were still cripplingly expensive, so these panels used standard Kingbright Gallium Arsenide green LEDs.
Each panel was hand etched, drilled and populated with 64 LEDs and 8 flip flop circuits. Each flip flop controlled four LEDs on each side giving control over the full 64. It's hard to see on the panel when it's running, but there are groups of four LEDs scattered across it, with a matching group of four that alternate back and forth. Each flip flop circuit runs at a different frequency, so the patterns on the front continually change. There are always 32 LEDs lit at any given time which makes a large array of the panels look very smooth with no significant jumping or flashing.
The panels are designed to butt up against each other to form large arrays of lights.
A lot of work for a show that bombed after one series. A lot of shows bomb after a single series, even good ones. That particular one was not very good. (I'm not going to name the show.)
Because the boards were hand etched they were made as single sided PCBs with the rats nest of wires connecting all the randomly placed LEDs. I say randomly placed, but in reality it took a lot of work filling in an 8x8 grid of boxes with letters denoting the channels to get a good spread of the LEDs with none on the same flip-flop next to each other.
Surface mount components were available, but I found it easier to design the board for standard through-hole components mounted on the solder side.
This panel is in a frame because it's a bit of a souvenir from that job. I've got a few prototypes, but the rest were most likely scrapped when the show was cancelled. The BBC just destroy all props and sets associated with a show when it is cancelled, to free up storage space and prevent props being taken and sold or re-used by other production companies.
Each panel was hand etched, drilled and populated with 64 LEDs and 8 flip flop circuits. Each flip flop controlled four LEDs on each side giving control over the full 64. It's hard to see on the panel when it's running, but there are groups of four LEDs scattered across it, with a matching group of four that alternate back and forth. Each flip flop circuit runs at a different frequency, so the patterns on the front continually change. There are always 32 LEDs lit at any given time which makes a large array of the panels look very smooth with no significant jumping or flashing.
The panels are designed to butt up against each other to form large arrays of lights.
A lot of work for a show that bombed after one series. A lot of shows bomb after a single series, even good ones. That particular one was not very good. (I'm not going to name the show.)
Because the boards were hand etched they were made as single sided PCBs with the rats nest of wires connecting all the randomly placed LEDs. I say randomly placed, but in reality it took a lot of work filling in an 8x8 grid of boxes with letters denoting the channels to get a good spread of the LEDs with none on the same flip-flop next to each other.
Surface mount components were available, but I found it easier to design the board for standard through-hole components mounted on the solder side.
This panel is in a frame because it's a bit of a souvenir from that job. I've got a few prototypes, but the rest were most likely scrapped when the show was cancelled. The BBC just destroy all props and sets associated with a show when it is cancelled, to free up storage space and prevent props being taken and sold or re-used by other production companies.