I am trying to design a dimmer circuit with the arduino and the lamp on a different power supply. This is my first time trying to design something using Eagle so go easy on me, but please feel free to critique my schematics =)
After a lot of research into the topic, I have a few questions that I hope you guys can help me with:
Do my circuits work? (First things first I guess)
Is my assumption correct that when using the second schematic, once the Arduino pin is low, the lamp is turned off, however not so when the first schematic is used?
How exactly is R1 and R2 calculated?
As far as I understand one does not need a fly-back diode for a lamp. However if you would like to install one in case the circuit is used for a motor, Is my assumption correct that it will be connected in parallel with the lamp?
Is it necessary to smooth the pwm out from the mosfet? Would it increase the life of the lamp? Similarily would that reduce the high frequency noise that some dimmed lamps make?
Is there anything else I should consider?
Components used: Mosfet IRF1010ZPBF: http://www.irf.com/product-info/datasheets/data/irf1010z.pdf Optocoupler 4N35: http://www.vishay.com/docs/83717/83717.pdf