Now for some practical stuff. I have created a simple breadboard solution for the driver circuit and hooked 7 Ledberg lamps up to NMOS transistors.
The breadboard is quite a mess! whats in there is:
on top a PIC16F688 MCU. below that is a 7805 linear regulator for supply. The input voltage is supplied from the Ledberg 12V adapter and below and the rest of the breadboard is the mosfets and pull-down resistors. Basically I am having a giant common anode 7-segment display. Apart from the mosfet stages the display behaves completely like a normal 7-seg display.
This is how it looks. Ambient lighting is turned off. The color temperature is actually quite pleasing. Not to cold and not too warm. the lights give a good contrast when on and is blinding up close (its going to be crazy when 4 displays are on at the same time!)
Here a ‘5’ with the ambient lights turned on (my desk lamp). The digit is still very much visible and readable. A haven’t tested the digits from a great distance but the get more ‘understandable’ when moving a bit away – simply because of the size of the digits.