Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

previous by date index next by date
previous in topic topic list next in topic

Subject: Re: [Homebrew_PCBs] Re: laser ablation of paint on copper clad

From: Slavko Kocjancic <eslavko@...>
Date: 2014-12-10

With 20mW I can work pretty fast. But still the power is limiting
factor. With 100mW laser I think I will hit other bariers like speed of
scanning and even more the speed of laser modulation. With 100mW laser I
need to switch it on and off at 1MHz rate. I search the net but didn't
find the working driver. Now I have driver from BJT transistors and
works nice at over 100kHz but the current is little dependent of room
temperature.
I tried to modulate LM317 but in some cases seems that it resonate and
miss pulse. OPAMP seems to be too slow (at least with amplifiers I tryed).
I don't know what is best for laser. To turn it ON/OFF completly or just
change the current from minimum lasing current to max current.
And I have little different approach in mechanic... need to make video
how I did it...

Slavko.

On 10. 12. 2014 10:24, Cristian crissstian@... [Homebrew_PCBs] wrote:
>
> No more than 120mW for uv photoresist exposure, otherwise you will
> experience strong reflections.
> Cristian
>
>
>