OK
this one
or this one?
The difrence is in Power Supply & Control Interface
But I do not have any Idea which one to take 
One of these clearly says it needs a 5 v TTL. That’s great info to have. The other doesn’t say from what I can see. (The web page didn’t display correctly on my cell so I could be wrong).
The one that doesn’t say does have a cool feature though. It has the weak light button. That is a button you can press and it will turn on the laser at the lowest power setting. That makes it easy to focus the lens before a job. Most of us have to do that from gcode or the lcd to turn the laser on or off at the lowest power setting.
The other difference I saw between these was the wavelength. Again it was really hard to read on an iPhone but it looked like one was 405nm and the other was 445 nm. I don’t know if this makes any difference at all for cutting or engraving. but make sure you get safety glasses that are usable for the laser you buy.
For safety, cheaper glasses are not something I would trust.
edit. I think I was wrong. They both appear to be 445 nm. Same warning though. Get good glasses that match the wavelength. And more than one pair because friends or family will want to see the machine. It always happens.
both are 445nm and both use 0-5V TTL PWM (check all pictures)
the difference is that different control boards
SW-LD45-V3.0 on FB03. use single 3-wires cable for power and pwm
SW-LD62-V2.0 on FB04. use 2 separate 2-wires cables for power and pwm
Yes and the question is: should I get the 2 wire or 3 wire version for RAMPS 1.4 bord?
I received the 15W laser. Mounted and used the same wiring and programming as the 4W version. TTL control board is different from the one I got with the 4W version. Was able to cut through 6mm birch plywood, never was able to do it with the 4W version. May install an air assist to make sure the cutting path is clear of debris. Interesting that the 15W version was only $30 more than what I paid for the 4W, both were from ebay.
Probably because 15w is just 5w laser crystal in impulse mode and it’s not continuous output of 15w
So I’m trying to set up my laser and it has two sets of two wires, I am using the Rambo 1.4 and I think I am supposed to connect the power cables up to the Fan 1 and the TTL up to the 45 pin.
Is that correct?
The TTL is a 5v controller for the laser I have.
Thanks for any help.
Kyle
You would only need either the fan or pin 45. You probably want to connect ttl up to pin 45 and the other up to 12V (the power supply).
So power the laser direct from the power supply and the TTL will turn it on when needed?