I know computer fans can be run with mobile phone chargers because I've got it to work just by finding and joining the relevant wires (live and ground). That's about the limit of my knowledge and experience, though, I'm afraid; but I'd like to build on that. I want a bigger, better fan now. The ones I've done are noisy little 5v. blowers which aren't really man enough for the job. I understand I can get a 12v. fan to run from a mobile phone charger the same way as the 5v. ones do, and it will run slower and quieter. That's good; that's what I want. I understand a 12v fan may not start without an initial voltage of 5v., and if it does it may stall (and burn out) and this could be caused by a seemingly insignificant obstruction, or without any obstruction at all. If I'm not mistaken I also read somewhere that a simple diode or resistor could be worked into the circuit somehow somewhere to stop that happening, but I can't find where I read that now. That's what I want to find out about here: how can I do that?
Then, when I started thinking about it, it occurred to me that I might actually be able to make it a bit better and get exactly what I want: I'd like to be able to run the 12v. fan at full blast if necessary for short periods and then turn it down when things have cooled down. Is there any way I can do that: 1) make a 5v mobile phone charger put out 12v., 2) put a control on it to reduce the voltage, and 3) make it so it won't stall the fan? The fan I have in mind (this one: https://www.arctic.ac/eu_en/arctic-f12-tc.html) is designed to be run at variable speeds.
Then, when I started thinking about it, it occurred to me that I might actually be able to make it a bit better and get exactly what I want: I'd like to be able to run the 12v. fan at full blast if necessary for short periods and then turn it down when things have cooled down. Is there any way I can do that: 1) make a 5v mobile phone charger put out 12v., 2) put a control on it to reduce the voltage, and 3) make it so it won't stall the fan? The fan I have in mind (this one: https://www.arctic.ac/eu_en/arctic-f12-tc.html) is designed to be run at variable speeds.