Simple Connectivity Tester

[vanhansen]

Since I'm limited to what DIY stuff I can do until we get a new house, I'm using parts I currently have.  I came across a simple connectivity tester here: http://www.soinc.org/cantjudge/condtstr.htm

What I'm curious about is the resistor is 330 ohm hooked to a 1.5-2.5V LED.  Wouldn't that make the LED pop with the 9V battery?  Say I want to use this to test connectivity between points in a circuit (my DMM doesn't have a beep mode), would the 330 ohm be OK or should I go with a higher value?

If I decided to use a 1.5V AA instead, would the resistor still be necessary?

I'm planning on putting this on a small piece of perf with a battery holder and one wire coming off it.  The other lead would be solid sticking off the end of the perf.

I know, silly little circuit but what the heck right?  

[ninoman123]

I built one like that with a little piezo buzzer I bought that runs off of a 9 volt battery. I would rather hear something than hafta look up at a light everytime. Its faster when going from trace to trace.

[vanhansen]

Ah, a buzzer. Duh, why didn't I think about that.  :oops:

Now, how would the LED and buzzer hook up if I wanted both?  I'm guessing that the buzzer would connect coming off one side of the LED just so long as the circuit is completed when the probes touch.

Are their piezo buzzers that work of one AA battery?