Its new tech but its not magic. Its control circuitry that monitors the voltage across the mosfet and opens the gate if it gets too high...I can build that myself with discrete components, its not new, its just integrated so less external components can be used.jharvey wrote:Have you noticed the discharge times for the spice on pg 3 of this thread? The autoFET drops like a rock, because it drops so quickly, the off time tolerance is tighter, so more accurate control.
I know that freewheel (snubber, fly-back, suppressor, catch, TVS, ect) component is very common. However it really rolls over from the relay days, when there were no other options. I think the autoFET shows newer tech, increasing quality. If the dissipated power for the autoFET is really a fraction of a watt, that would be something. I think there is a good chance it really is that low. Most FET's get hot because this spike can put you in a tranient zone, where you're simply a resistor across the battery. However, this isn't a normal FET, it appears it will make that transient period much shorter then normal.
I'll be eagerly waiting for Fred's reply.
http://www.datasheetcatalog.org/datashe ... Xutyrr.pdf
If you look at the circuit in fig 5 for testing switching times of inductive loads it uses either a fast recovery diode, or another fet to shunt the inductive spike. Sure it will work without, but its not a good idea. Just because they have incorporated a system that prevents bad design from destroying the device, doesn't mean you should then ignore good design.