Originally Posted by TXFred  I'm working on a way to run the X2's spindle from the Gecko G540's VFD drive.
It looks like the motor control will work just by hooking it up to the G540. The part that is tricky is the switch that's built into the potentiometer. This is used to reset a spindle fault on the mill.
The easy solution is to just have a switch to activate the spindle. But I'm after more. I've designed this simple circuit which will trigger an emergency stop on the G540 whenever there is a spindle fault. That way, if the spindle stalls, the stepper motors won't keep moving and cause more damage.
When the spindle stalls, the Spindle Fault line goes to +110VDC. This activates the relay or opto isolator, which opens and triggers an emergency stop on the G540.
The momentary switch is to reset the spindle fault. The resistor is to limit the current through the relay, so that the relay side of the circuit won't reset the fault. This is similar to what is on the mill now. I've just swapped out the orange light for the relay/opto.
It should be noted that this circuit maintains the isolation of the G540 from the X2 spindle control so long as a mechanical relay or an opto-isolator is used. A solid state relay would eliminate this isolation.
The problem I see is this. I haven't found a good relay or opto that can handle the 110v that the X2's board is putting out. At least, I haven't found a cheap and small one.
Does anyone know of a relay or opto that will work here?
Alternately, what's a good way to take that 110v and reduce it to 12 volts so I can use a regular automotive relay?
Cheers,
Fred |
The LED on any opto, and the "coil" on any SSR, can operate from pretty much any voltage, as long as it has a suitable series resistor to limit the voltage the LED sees. Figure out what current you need in the LED, and divide the input voltage by that current to get the required series resistor value. The problem will be the required power rating of that resistor, due to the large voltage across it. The phototransistor side is more voltage sensitive, since it will see the full supply voltage when the opto is turned "off". That shouldn't be a problem in this case.
Regards,
Ray L.