450nm LDs? I see huge power ratings here,

450nm LDs? I see huge power ratings here, like 5 W - raises my eyebrowns a bit.

The weird thing is that I don’t see the LD types too often mentioned. What are they?

I have a hunch that some of the specified ratings are peak powers, respectively run with low pwm ratio? Or am I totally paranoid?

Can someone tell types of some LDs rated 3-5 W?

DTR Laser shop sells some high power Laser diodes. He tests each one with a laser power meter, his highest rated one pegs the meter at 6.8W, but he figures it actually is higher than 7W. I have one of those diodes, and will let you know in non empirical terms what I think of it in a day or two once I have it up and running.

Ok, I’ve talked to DTR, his stuff is good.

DTR Laser are great to deal with. We have been dealing with them for a number of years now and they are very reliable.

Something to keep in mind with laser diodes is that more wattage does not always translate to better cutting. Unlike CO2 lasers, diodes tend to produce a rectangular shaped beam. It seems that increases in power tend to increase the anamorphic nature of the laser beam shape. This means that without the right lens focusing that irregular shape, you can often end up with worse performance with higher wattage diodes.

So far we have found the NDB7A75 to be the best balance between power and ‘focusability’. It doesn’t have the grunt of the of the NUBM diodes as mentioned above but can work very well with a standard 3 element glass lens.

My best suggestion is do NOT skimp on a quality power supply. I popped two of the ~4.5W ones because my power supply dipped to -0.8V when turned off under full load. Just one day nothing.

uMind… Can you show your controller circuit diagram? Sounds like unprotected to me…

I ditched the 450nm design and got a 40W CO2 Laser. I started out back when the first 450nm engravers popped up around 4-5years ago when overdrive controllers where custom designs. Needless to say my design had high voltage crowbar protection but I did not count for the power supply feeding the driver to dip negative. The negative dip is common on adjustable power supplies when you turn them on/off with the load connected. You want to turn the supply on THEN your load and reverse at power down.