Hi guys,
To preface:
I built a CNC router a few years ago and among several projects I’ve made some cool Plexiglas plaques and such. An example of something I have made is posted below. I created a base that accepts AAs, has a switch, and the appropriate resistors to power the LEDs. This is relevant because I plan to create a similar project, but have run into a snag (My lack of knowledge).
As for my electronics experience, I have dabbled in repair and modification in the past. (N64 RGB mod, replacing failed caps, etc.) However, I have no experience in "creating" something, or utilizing transistors and such, so I apologize in advance for my mediocre description skills.
My project idea comes from something I use at work. there are six of us in my office, and we have some equipment that we need to keep an eye on, so for us to track who has it, there is a laminated piece of paper that says “IN USE” on one side, and “NOT IN USE” on the other side. Below it is a white board. When you use the equipment, you flip the paper over and write your name on the board. This is just a simple way to let us all know the status. No big deal, but also not that fun.
I thought it would be fun to improve our process with a "modern" solution.
I plan on creating an etched Plexiglas sign that is edge lit by LEDs similar to the picture I posted below of an earlier project.
I will create a Plexiglas sign with LEDs as follows:
IN USE
NOT IN USE
NAME 1
NAME 2
NAME 3
NAME 4
NAME 5
NAME 6
I initially figured I would supply 6V DC power via a simple external power supply, add the appropriate resistors in line to each of the LEDs that would illuminate the etched names, with switches to turn on each one. nothing complex there at all, but as I thought about it I felt that manually switching on the “IN USE” and “NOT IN USE” lights independently of the names would be redundant. I would like it to behave in the following way: When no “name” is powered, the "NOT IN USE" light should be illuminated. When one or more name lights are active, the "NOT IN USE" light should be off and the “IN USE” light should be illuminated, so it seems I need to create some sort of logic gate.
My initial drawings start out with +6V input going to six switches. from each switch I add the appropriate resistor before the LED. I was looking at using a transistor as a switch for the "IN USE" light by tapping the + after the switches. Obviously doing so before the LED would just end up powering all of the LEDs as soon as I turn one on, so I was thinking of putting it behind the LEDs as I understand they pass voltage forward. Will this work the way I think it will? can I switch on the separate "IN USE" circuit by tying in a transistor after all the LEDs? Also, I have been reading about modes of operation. Do I assume correctly that I can do a variation of this to have the "NOT IN USE" circuit in a normally on state, but switched off when current is applied through the switches? I feel like I'm close, but I want someone that know what they are doing to tell me if I'm looking at this the right way or not. Anyone that can point me in the appropriate direction would be appreciated, as while likely a basic task in the world of electronics, it is a step forward in complexity for me, so I'm a bit unsure.
Here is a basic draft of what "I think" might be close to what I am going for. I'm sure I'm not formatting it right, but would such a creation work the way I think it would?