Quote Originally Posted by Neale View Post
Slightly more general comment - if this is for a router, I'm not sure if you ever need to reverse the spindle. Just forward is enough. So scrap that transistor and extra relay altogether and use the BOB relay to switch the VFD "forward" connection directly. Much simpler. I have never had "reverse" available on my router - and in the few years I have been using it, never needed it.

Apart from that, I'm with Kit - it's just a little too fuzzy to clearly see all the detail.
VFDs get used for all sorts of motors including pumps, conveyors and traction as well as routers. Some applications might want to reverse the motor but I'm with Neale if this is for a router. KISS rules!

Kit