Laser Power Supply PWM Control Not Working

[zberry]

I am having some issues getting the pwm power control to work with my power supply. I ordered a 60w power supply and laser back in July and i'm just now getting around to getting it installed. I have a 3.3V pwm output on my smoothieboard http://smoothieware.org/smoothieboard connected to the IN pin on laser power supply. I can get the laser to fire with this setup, but the laser does not seem to respond to commanded power change. I thought it could be that the power supply needed a 5v pwm input, so i used a logic level converter to bring my 3.3v pwm signal up to 5v. The laser will still fire, but again it does not seem to respond to the pwm signal. I have also tried using other pwm pins and get the same behavior. Could something be wrong with my power supply? I have a current meter on order so i can see what power the laser is firing at. Can you suggest any other ways to test the power supply to determine if it is functioning properly?

Thanks.

[Tech_Marco]

You can test it by applying DC 0V~5V signal to test output. If it work, that means something wrong with your PWM signals. I think the maximum frequency response of PWM signal is 100KHz. You may try 20KHz to 50KHz.


Marco