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[on:]

Hello,

My project is a timelapse utilizing a DSLR, arduino, steppers, and some USB devices. Their various power consumptions follow:

USB (arduino, GPS, etc) = 5V 2A
DSLR = 7.4-9 V 2.5A
steppers = 12 V

I will use a single 12V source ([3S3P 3.7V LiIon batteries, or 12V DC wall wart) to power all of this. 2 voltage regulators will step down the 12V, 1 to 5V for the USB hub, and 1 for the DSLR.

My concern: This equipment is expensive to me. What suggestions do you have to protect this stuff form a voltage regulator (or wall wart) blowing and destroying the camera, etc? The obvious solution is a fuse.

As far as I can google, a fuse will give over–current protection... but is this what I want? Would this not protect me from over-voltage, the thing I should be most concerned about? If so, what kind of fuse ratings would I choose? E.g., would I want the fuse to burn up quickly or slowly? What voltage/current/other ratings would be appropriate?

Thank you for the help.

[Reply #1 on:]

fuses mostly protect your power source not whatever is drawing the current... if you have something seriously screwed up to toss a fuse it may have been too late

as far as overvoltage some simple 78 series 3 pin regulators will take care of that (7809=9v, 7805=5v etc) they limit themselves at a total MAX of 1 amp if everything is sparkling white perfect. similar higher current models are available but 2.5a is something that some more serious desgin may be needed

(why is an arduino sucking 2 amps?)

[Reply #2 on:]

The project is still in assembly, so I do not have a definitive power draw yet. The USB hub will eventually service multiple devices, not just the arduino (i.e., external flash drive), with a max of 2A.

Thank you for the help—exactly what I needed!