Ready Steady Eddy

[EddyCurrent]

My breakout board has a charge pump output that I'm currently not using. Mach3 is using it but I think I will look at incorporating it into the hardware stop circuit as your drawing shows.
Also, and this is very important but open to interpretation, I am not removing power from the spindle inverter during emergency stop, I mentioned this is another post. The reason is that the inverter can stop the spindle faster than it will stop on it's own, it does this by applying dynamic braking. Other options for bringing the spindle to a timely halt would be a spring loaded mechanical brake or as in the case of my table saw, a DC injection braking system. Removing power to the inverter via a contactor is the obvious emergency stop strategy and it could be said that removing power from the inverter under load will damage it, that might be true but better to have a damaged inverter than a damaged limb. According to the machinery Regs. which won't apply in a private houshold situation, the spindle should stop within 10 seconds, now I've not had my spindle up to speed yet so time will tell how long it takes to stop on it's own.