Two questions really:
1: I have some old LED's but don't know what the forward voltage or current is for any of them. Is there anyway of finding out ?
2: If I have some LED's with a Vf of 3.4V and If of 30mA could I wire
94 of them in series and connect to mains AC supply of 230V with no limiting resistor. I have suggested 94 because this is 320 divided by
3.4 ( where 320 is the peak V for 230V RMS).