Setting up a AWC708 Controller

[bush flyer]

When others have been setting up there controller has anyone changed the Laser parameters PWM frequency to something other than the factory setting of 20000hz. If so can some one tell me what to set it at, and where do you find the information. I just don't know what to set mine at, or do any damage if it is left at 20000hz?

[sshwarts]

My understanding is that this is the best frequency to use for most of the laser power supplies and the common 40W ish CO2 tubes. It's a function of the low pass filter they put on the PWM input. Remember that the power supply uses voltage (0-5V) to adjust the laser current. The PWM signal is filtered to produce a voltage in that range.

In my case, my power supply is larger than than 40W tube I use so 100% is not 5V but about 35% of that. So I have to be careful to set the maximum in the AWC setup to that.

As a side note, I've seen people put a voltage divider on the AWC output so that 100% is actually the lesser value, but I don't see what that really buys you.


Scott

[bush flyer]

That's great sswarts, That's put my mind at rest, I spent a long time trying to find that information with no luck. Many thanks I appreciate your help.