2017-07-29, 14:23
(2017-07-27, 22:26)allsorts Wrote: 1 A is ample for a Blitzortung controller, if I remember correctly a controller draws 400 to 500 mA. Disipation in a 7805 is dependant on the voltage drop across it and the curent flowing through it. Minimum supply voltage is 7 V so it's dropping 2 V @ 0.5 A = 1 W dissipation, don't think that would need a heatsink. Feed it 12 V the disipation rises to 3.5 W, that probably will...
A post supply filter stops the noise getting to the controller via the power lines but doesn't stop the noise being radiated from the PSU itself or other wires connected to it. I'll admit I have post supply filter but I use PoE so don't (easily) have the option of a linear supply.
Yes, you are correct, I was thinking more along the lines of the Raspberry Pi projects I have that need 2-3A, a 7805 should be fine for Blitzortung, I don't worry too much about the PSU radiating noise as it is only one if around 20 in the same room and I don't plan on changing everything to linear supplies.
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