Yes, it is an inverter. I did Google this page but that's why I picked it... because it was what I remembered using in Vo-Tech classes all those years ago. I did not specifically remember the Schmitt trigger inverter but I did remember that there was an RC circuit that you could use to make PWM that used a certain inverter chip. It was only partly from memory but mostly from looking it up.
You're right. There probably is an IC that does it all for you but this is the way I think. If you can find such an animal there's no reason not to use it.
You're talking to the guy who spent the better part of a weekend aligning his enlarger to within 140 microns. How else do you think I'd go about it?