Despite the fact that I still haven't quite finished the last clock I was asked be build (just waiting on one last thing to arrive), I have been asked to build another.
This time its a digital one with oversized digits. The display should be white in colour with each number being about 3 inches tall. should ideally run from AA batteries. This clock will be for some one who is partially sighted.
At this point I am thinking 10 LEDs per segment, there is no need for decimal place, but there is for a colon separator between hours and minutes, second do not need displaying.
It would be ideal if it was able to pick up the MSF (or similar) clock signal as well as keep it own time if needs be.
The first hurdle I think is getting the seven segment displays to work as a normal seven segment. I am thinking that a transistor (maybe a mosfet will be better?) from each segment and a logic level mosfet to act as the common cathode would make the display work with most display drivers if I were to choose to go that route. It would be simplest I think to have a display driver, I am open to suggestion on components and circuit suggestions at this point.
I quick glance through some white LED specs show they are around the 3v vf, so wired in pairs with no resistor for 6 AA batteries should give fairly uniform results across the hundreds of LEDs.
I have no idea on how to deal with radio clock thing, it on the research list, but I suspect there are some here who have already dabbled in that.
any thoughts on this, am I going about it wrong?