You need to learn PWM circuits. The simplest way is to use a 555 timer chip. Check the AAC ebooks. There are lot of tuts. Learn the theory and try to make one. As for switching the 19A load. It is not that of a problem based on the power of the recent Mosfet's available today.
Your load handling is the easy part. The PWM drive circuit is the complicated one. Get that right and ur circuit is done.
So go thru the books or google PWM using 555. make a circuit with a Led as output and post the results. Then you'll get ways to use the Mosfet.
Your load handling is the easy part. The PWM drive circuit is the complicated one. Get that right and ur circuit is done.
So go thru the books or google PWM using 555. make a circuit with a Led as output and post the results. Then you'll get ways to use the Mosfet.