I have the following circuit, different for the one I post before. The idea is to gets up the Voltage from 12V to 15 V and then use a pwm signal to gets a 15 V pulsed output:
I have found a more or less correct signal when there is no load applied(15 V applied with no load).
But when I connect the load (a string of leds), the pulse gets down and doesnt mantain 15 V constant, and goes down to 12 V. So the leds doesnt mantain the light intensity. Also, the pulse has a lot of noise( the noise is seen looking live to the osciloscope, im sorryI can not show it in the image).
Some ideas what should I test ? I am not worried about the noise, It will be longer or not to fix it, but I am totally mess up with the pulse. I have no idea of what is happened.