cyclegadget:
I found a handful of IRF3205 MOSFETs and I was wondering if the 5v Arduino can operate these. Some of the information leads me to think that the gate requires 10 volts.Thanks in advance for any help,
Mark
It's only rated for 10V on the gate. It might work a bit at 5V but it might not - different devices will behave differently and its behaviour will change with age and temperature.
If a device is logic-level it will have the Rds(on) given for Vgs=4.5V (or sometimes 5.0V). Internation Rectifier logic-level FETs generally have an "L" in the part number, note.