Array switch circuit design

Question

I am attempting to design an "array switch" where a user can toggle a switch and a different array of LED's are turned on based on multiple reference traces. The picture is my best attempt so far. I have not been able to build this yet, but from my basic electrical knowledge, it should work.

The goal is for the 3 reference HI/LO traces to actuate two separate LED's based on the switch position, 1 LED from array 1 OR 1 LED from array 2 depending on the switch position.

Question 1) Will it work? Question 2) Is their a better way to do it?

Answer 1

There are a few issues. First, you should provide separate base resistors to each transistor, rather than tie them together. They would need to have the same Vbesat to give you consistent results, so separate base resistors would be better.

It's also a little unorthodox in that you are bringing in the switched input to the collectors, rather than driving the base from your hi/lo signals, and just putting power from the top switch. In this case they are just LEDs, so the current is probably not an issue, but the more conventional way to do this would be to bring the signal to the base, and power to the load and collect.

The main issue is that you put the loads in the emitter. If your hi/lo signals are not high enough voltage, the transistors won't turn on at all. Below is what I would do (for each input).

^{simulate this circuit – Schematic created using CircuitLab}