What is the function of the little black box on the sculpfun automatic air assist? I am thinking in the direction of enabling a minimum air flow with a relay and a secondary power supply even when the lightburn gives the command to turn off the air assist for engraving.
You want full air during cutting, and a little air during engraving to keep the lens clean.
Notice i did not make that a question? How about putting in a Tee and dumping some of the air when engraving? A switched solenoid is better, but I just added a PVC ball valve on the Tee line and open it when I am engraving. Same job, no wiring or extra power supplies.
This is also a solution, but it requires monitoring the work phase. I would prefer automatic switching.
That’s an inverter board, the laser mainboard supplies 12/24V DC (depending on your model) and the pump uses 12/24V AC.
The port on the mainboard can drive a relay or ssr without problem, so you can design your required solution. The A9 model of Sculpfun already provides this, the pump always runs at 10% and is put to 100% when air assist is activated. But this is not supported by the older mainboards.
If you have a 24V system, you could use the relay to switch between 12 and 24V, whereas 12V will result in 1/4 of the pump power (if it’s a 24V pump).
Some additional details:
1 Like
Thank you, that is what I need.
1 Like
Successfully completed project, here is the circuit. DC/DC step down is used for fine adjustment of the air flow during engraving.
2 Likes
My SF-A9 does this automatically, but I might have to add it to my S30 machine. Nice work!
EDIT: Just checked my S30 Pro power supply and it is 12v. My air pump is also 12v. Did you modify your machine? Are you sure the controller pin output is 24v?
I ordered 22w upgrade kit and it come with 24V power supply.
1 Like
Wondering… Does your controller board (on-off) switch the output for the air, or does it supply 12vdc (or 24vdc) like the S30 board does?
If it only switches it (source or sink output) you may need another part and a slight change in the wiring.
1 Like
When cutting, the S30 control panel switches the relay ON and the same 24V supplies the air pump, while when engraving the relay turns off and the air pump gets power from an additional 12V power supply. And the relay has a built-in flyback diode.
1 Like
Where does the little black box fit into this? Its not clear to me its function if the MB already is supplying 24v - does the relay to switch between 12v and 24v go before it?
Little black box stay as it is. Relay output is connected to black box. MB supply 24 V for pump and for changing the state of relay.
No, the box is an inverter. The pump uses 12V or 24V AC voltage, the mainboard supplies 12V or 24V DC voltage.