The way Terraria uses timers is annoying.
If you make a complete circuit, the signal will go in both directions. Also, it doesn't turn on the timer, which will then activate every 1/4 second (or whatever), it will instead act as a "gate" for the timer duration, then the signal will move onward, and the timer will not turn on again unless it receives another signal.
That's nice in a certain situation, but not if you just want a simple timer setup. It would be so much easier if there were transistor objects, because this doesn't work like real circuitry, which only goes the power to ground, if we're talking about DC circuits (AC is different, and I don't know remember it too well).
I've seen there ARE transistors, but they're all from mods. Since 1.4 is the last update, it's unlikely they will add or change much about the game. IMO it's odd the way they implemented electronics, because it doesn't seem useful for anything besides "flip a switch, one thing happens".