Here’s an interesting technical problem of which I wasn’t really aware. Those of you that regularly tow a trailer, though are probably quite familiar with this, the issue of braking and trying to use a turn signal at the same time. Creator Kevin H. Patterson sums it up this way:
Most basic trailers have a 4-wire connector with only 3 signals: Running (aka Tail) Lights, Left Turn, and Right Turn. The trailer does not have a separate circuit for Brake lights; applying the Brake is supposed to light up both the Left and Right Turn signals together.
This may not sound like a big deal, but if you’re braking and turning, this means that the brake/turn lights are continuously held on, giving no indication of where you’re actually going. Another issue, though perhaps not as serious, is that the diodes normally used to hook the trailer up to the vehicle’s brake system also reportedly dissipate a lot of heat.
Patterson’s system, per his description, “uses XOR gates to intelligently combine the brake and turn signals.” What this means is that when you apply the brakes without a signal, things work normally. If, however, a turn signal blinks on with the brake applied, the corresponding turn/brake signal goes out, telling the vehicle behind you your intentions.
It’s a neat potential solution to a problem that I didn’t even know existed. On the other hand, be sure to check out the legal disclaimer on the bottom of the linked page and consider whether it’s legal and/or safe in your particular situation.