开云体育

A Schottky diode in series with power to the rig should work fine for reverse power supply protection.
The lower forward voltage drop of 0.3v (vs around 0.6v or more for standard silicon diodes like a 1n4007)
means the rig sees something closer to the 12v coming from your battery.
It also means the diode does not get so hot, ?with 2 Amps at 0.3v that Schottky is dissipating 0.6 Watts.

I'd recommend separating out the main rig supply and the supply to the IRF510's.
For higher power, you may want to give the IRF510's more than 12v.
Also, it allows any fusing and reverse supply protection to be more effective.

The main rig can live fine with somewhat less than 12v, and only needs 150ma or so.
Could use your series diode (schottky or 1n4007), or the hfsignals scheme of a reverse shunt diode plus fuse,
or in my case an LM2940CT-12 regulator (which unlike an LM7812 provides reverse voltage protection).
In any case, this should be protected by a fast blow fuse of maybe 0.5 Amp.

The IRF510's only need a 3 Amp fuse to protect them. ?The intrinsic diodes in the IRF510's will conduct
if a reverse supply is applied, blowing the fuse. ?Fuse will also go if you set the gate bias voltage too high.
If you don't include a fuse, it will be the traces of the board that blow when current goes beyond 3 Amps
as many Bitx40 owners have found out. ?

Perhaps next rev of the uBitx board could have very thick traces for that IRF510 drain current
except for a short moderately thin trace, a plated hole drilled at each end of that thin trace. ?
The thin trace is your first fuse, once that is blown you replace it with either something like
28 gauge magnet wire or an honest-to-gosh fuse.

Could also do something similar for the main 12v supply to the rig, but with a skinnier trace.
Then the only explicit reverse protection device required is the main rig reverse protection diode,
probably series is best though shunt should work. ?I'd be a bit suspicious of a 1n4007 shunt diode,
since with a high surge current the forward voltage drop across it will rise above a volt,
might be enough to blow some IC's.

Would also be nice to have some way to monitor heat at the IRF510's. ?
Occasionally putting your finger on the heatsinks to check how hot they are might be good enough.
Or sprinkle them with something that starts to stink at 60C or so.
A more elaborate scheme would sense the temperature and yank down on the IRF510 gate bias voltage if it gets too hot.
If giving the IRF510's more than 12v, I'd recommend going to a larger heatsink than supplied with the uBitx,
and also insulating the heatsink from the IRF510 devices. ?

If you don't insulate the heatsinks, be sure to keep loose wires from hitting them as the heatsinks are at 12v.
A number of Bitx40 owners blew out their Raduino when a spare wire passed by the heatsink.

Jerry, KE7ER