In 2006 I bought a CNC machine from Bert Eding, the owner of Eding CNC.
It came with the CPU2 controller board.
It is hard to find any documentation on the CPU2 controller, but from what I can see it supports:
4 axes, End-Stop on 4 axes, Spindel On/Off, Cooling Mist, Cooling Flood, Tool...

Over the years I have been very satisfied with the machine, it isn't huge, just 585x370mm workarea, but it's enough for me.
Recently I purchased a cheapish 15W LED Laser module from AliExpress, as I didn't want to shell out the big bucks for a 60-80W CO2 laser setup.... yet.
It can be PWM controlled, but by just applying 12V, it outputs max power, whether this actually is 15W remains to be seen.
I have already test cut up to 10mm balsa (in 3 passes at 600mm/min, slightly black) and 3mm balsa in 1 pass at 600mm/min (nice brown color).

When I plug the laser into the mains, it doesn't switch on yet, but produces a very low wattage aiming laser-point.
Not until I press a small switch on the laser does the full 15W come out.

My problem now is, how to make USBCNC control the on/off switching of the laser.

Bert Eding, build-up the electronics in such a way that on top of the Z-axis there are 2 220V power sockets installed.
One is constantly supplying 220V AC, the other one is controlled by the Spindle On/Off of the controller board.
As in "laser mode" the USBCNC software uses the Spindel On/Off channel to switch the laser beam, it would be the simpelest way to hook up the switch of the laser to this outlet.

But...
The Spindel On/Off outlet supplies 220V, I just need a relay (preferably solid state) to act as the switch on the laser.

I have searched the internet, there are plenty of solid state relays that will take a 12V input to switch a 220V output.
But I would need one that uses a 220V AC input to just connect 12V DC circuit.

Does anyone have an idea how I could solve this?

Thnx.