I'd put that fuse in the +12 line first.?
Easy to imagine supply ground having an alternate path through house wiring and RF ground rods,
vehicle sheet metal, etc.? I believe Allison once said she puts fuses on both +12v and ground,
which is more than I usually see.
Splitting it into two portions, fusing most of the rig at 0.5 Amps and the IRF510's at 3 Amps,
means you don't need a smoke inducing event within the main part of the uBitx to blow the 0.5A fuse.
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On Thu, Jun 7, 2018 at 02:26 pm, <entilleser@...> wrote:
In the event that the power supply voltage is reversed, the reverse polarity protection diode, as suggested by HFSignals, will short circuit the power supply.? If the power supply has a small enough fuse, the short circuit will cause that fuse to blow, which will disconnect the power supply, therefore protecting your uBitx.? However, if the fuse in the power supply is too large, the diode may burn out before the fuse does, resulting in the reversed polarity being applied to your radio, causing damage.? It seems to me the simplest solution is to put a 2A fuse in the ground line before the diode.? If the polarity is reversed, the diode will still short circuit the power supply, which will result in blowing the 2A fuse (and therefore disconnecting the power supply), rather than burning out the diode.? Then you don't have to rely on an unknown fuse in the power supply itself.
