Assemble a Universal PCB

Step 16 Required Assembly: PTC Fuse

PTC stands for 'positive tempoerature coefficient'. The idea is that if too much current goes through the PTC, the temperature goes up, causing it to increase in resistance, even to the point of infinite resistance. It acts like a circuit breaker; if there is too much current going through, the PTC gets hot and disconnects the circuit until such time at the PTC has had time to cool off. Because it cools off, it is a circuit breaker that resets itself if it has has a minute or so to cool off. Protects components, doesn't permanently blow up, and requires nothing more than a little time to reset itself. Very nice to have.

All current powering the board goes through the PTC; as such, it will protect the board, but doesn't protect things outside of the board. If you make a short circuit in the console cable attached to it, the UPCB itself will probably be fine, but you're console is in trouble and will probably blow a fuse. That's why there are so many steps for testing a cable in the other instructable.

The PTC part recommended from Digikey has little bends in the legs. Because the PTC is susceptible to heat, you don't want it right next to a hot soldering iron. Those bends keep it a distance off of the board, making it one of the tallest components.

The PTC does not have an orientation, and can be inserted either way and still work.

Place the PTC into the holes so it rests on the leg bends. Bend the legs on the bottom of the board to secure it in place, solder, and trim off any excess wire from underneath. For now, have the PTC stand straight up. The legs are both connected to the main power coming to the board. You absolutely do NOT want any components touching or near those legs.