The program I used to draw the schematic is Kicad. It is free and open source. I highly recommend it.
It's hard to say if the arduino voltage regulator would fry if hooked to an unloaded 12V transformer. It depends on how much current the arduino is using. The 16V transformer you listed would most likely burn the arduino voltage regulator as it's unloaded voltage would be around 23V and the max voltage for arduino is 20V. You could always run an intermediate voltage regulator just for the arduino.. like a 7812 or 7808 (12v or 8v preregulator).
With the example linear supply you listed, the ripple may be fine as long as the trough of the ripple doesn't drop below your output voltage plus your dropout voltage. The R_thJA = 35C/W you have listed is for the regulator with no heatsink. You would definitely need a heatsink.. Assuming you are using a TO-220 packaged LM338, the R_thJC is 4C/W. If you couple that with a decent heatsink that is say 3C/W, you can have 7C/W ish total.. So for 17W that is an increase of about 119C.. Still a little too much. I would also be a little leary of the 5A rating of the voltage regulator. Usually there is a catch or very specific conditions where the rating is applicable... like assuming an infinitely large heatsink or something like that. I think practically for voltage regulators, you should cut their rated current output in half as a general rule of thumb.
As far as the heated bed is concerned, I don't believe 17W is not enough heat to run one. Also, controlling the bed temperature would be a pain.
Yeah, using a switching power supply like a computer PSU or the chinese $30, 30 amp wonder off of amazon is much easier and simpler than building a linear PSU. It's still a good learning experience to build the linear variety though. If I were you, I would try to build the 5amp linear power supply that you have described above with a potentiometer to adjust full voltage range. Then hook up an oscilliscope lead to the output of the transformer/filter, and another lead to the output voltage, and play around with it, adjusting the loads and voltages. Maybe hook up a temperature sensor to the heat sink as well.
It's hard to say if the arduino voltage regulator would fry if hooked to an unloaded 12V transformer. It depends on how much current the arduino is using. The 16V transformer you listed would most likely burn the arduino voltage regulator as it's unloaded voltage would be around 23V and the max voltage for arduino is 20V. You could always run an intermediate voltage regulator just for the arduino.. like a 7812 or 7808 (12v or 8v preregulator).
With the example linear supply you listed, the ripple may be fine as long as the trough of the ripple doesn't drop below your output voltage plus your dropout voltage. The R_thJA = 35C/W you have listed is for the regulator with no heatsink. You would definitely need a heatsink.. Assuming you are using a TO-220 packaged LM338, the R_thJC is 4C/W. If you couple that with a decent heatsink that is say 3C/W, you can have 7C/W ish total.. So for 17W that is an increase of about 119C.. Still a little too much. I would also be a little leary of the 5A rating of the voltage regulator. Usually there is a catch or very specific conditions where the rating is applicable... like assuming an infinitely large heatsink or something like that. I think practically for voltage regulators, you should cut their rated current output in half as a general rule of thumb.
As far as the heated bed is concerned, I don't believe 17W is not enough heat to run one. Also, controlling the bed temperature would be a pain.
Yeah, using a switching power supply like a computer PSU or the chinese $30, 30 amp wonder off of amazon is much easier and simpler than building a linear PSU. It's still a good learning experience to build the linear variety though. If I were you, I would try to build the 5amp linear power supply that you have described above with a potentiometer to adjust full voltage range. Then hook up an oscilliscope lead to the output of the transformer/filter, and another lead to the output voltage, and play around with it, adjusting the loads and voltages. Maybe hook up a temperature sensor to the heat sink as well.