Utility trailer taillight interface 2011-12-19

shokjok submitted a new article:

Utility Trailer Taillight Interface - This simple circuit was built 21 years ago, still works today.

The PCB is designed around the se

This simple circuit was built 21 years ago, still works today.

The PCB is designed around the selected relays. The brake switch is mounted on the bike frame, over the rear caliper and is activated by a long cable-mounted bolt below the switch. The signal and reverse switches are mounted in a 1" square aluminum block attached to the handlebar.
My trailer has an AM/FM/cassette radio, a new meaning to "show on the road".

View attachment 59414

Click to expand...

Read more about this article...

Use my circuit, posted in December of 2011, as a reference to wire the switches.
I made this circuit in 1987 as my bike trailer taillight interface. Switches mount on the bike above the rear caliper brake and in a tube on the handlebar. It is easily transferable to another bike or usable alone for bike lights. I recently added a set of amber front lights wired in parallel with the taillights so oncoming traffic can see my flashing signals.

I updated the circuit to eliminate the transistors and two resistors. A third relay was added to the REVERSE switch feed, the NC contact connects to 12V feed, and the arm feeds a fuse to the reverse lamps. The 2N3055 transistor is now disconnected and along for the ride. This circuit can be on 24/7, only drawing power when a switch is activated. I connected a solar panel to the battery when using this circuit, and electricity doesn't back-flow into the panel circuitry.