I played around with a 555 timer circuit and wanted to try hooking it up to something. I picked a 74HC273 from my collection, but I have never used one.
I'm sure I hooked it up wrong once or twice, but it still seems to work (I'll buy another soon to be sure). A LED I hooked up acted funny, and I realized I needed to tie the unused input pins low.
After that, the output seems stable, but it still doesn't work. The input and clock generally don't change the output, and the reset pin seems tied to the output. It also gets quite hot (measured around 50*C before stopping the power). I'm using a 5V USB wall charger for power btw.
I searched around for an example circuit and found this:
http://tok.hakynda.com/article/detail/59/sn54hc273-sn74hc273-octal-d-type-flip-flops-with-clearThis only makes me more confused. And recreating the circuit didn't work for me.
1) Why doesn't he have the Vcc pin hooked up?
2) Why is there a resistor on pin 11?
3a) How can I prevent it from overheating? b) Do I need to limit the current somehow?
4) Should I even be using 74HC chips for learning? Is there another line of basic components (gates, latches, counters, etc.) recommended?
Sorry for all the questions.
Carl