The NoGa PiG (Power indicator and Guard)

NoGa PiG

This kit from the North Georgia QRP Club goes way beyond the category of a handy QRP accessory. The PiG provides protection against reverse power connection, overload/short circuit, crowbar protection against overvoltage should your power supply regulator fail, and indication of low voltage from your battery pack. The circuit board also supports the optional addition of a PIC-based 8-pin DIP keyer and a passive audio hiss reduction circuit. So far, mine is the basic PiG. (Note: the Altoids box and custom artwork are not part of the kit, they're my own design).

While troubleshooting one of my homebrew projects, I blew the fuse from my battery four times and temporarily gave up. Those 5mm fuses aren't cheap at RadioShack. I mentioned the problem at a NoGa meeting in the summer of 2005, and Mike Boatright, KO4WX said,"Why don't you just finish your PiG? You won't need any more fuses." I'd had the kit for a couple of years and just hadn't gotten around to building it. The resettable Polyfuse in the PiG is great. It will isolate the circuit and sink the over-current. After you disconnect the faulty circuit, the Polyfuse cools and resets.

I have standardized all of my DC power around Anderson PowerPoles. I have DC input pigtails made up for battery lugs, bare wire ends and 2.1 mm center-positive coaxial plugs. So far, I have DC out pigtails for 2.1 mm and 2.5 mm coaxial plugs. I don't connect ANYTHING anymore unless it goes through the PiG!

Further information on the NoGa PiG is available on the NoGa site under "Kits".