I am embarking on a new project to design a circuit for an automatic vehicle signal actuator.
Outline of the project is this:
The problem: I have a car that has indicators operating on a standard 12v on-off-on toggle switch. As you can imagine this switch gets left on occasionally. Both misleading and potentially dangerous.
The solution: Replace the toggle switch with a 2 way momentary switch and create a circuit that supplies 12v to the existing indicator circuit for 5 seconds. In addition, the timer is continually reset when a 12v feed from the brake circuit is applied. As soon as the brake feed stops, the 5 seconds starts again.
Effectively, this allows a lane changing signal as well as a solution for waiting at junctions or to cross a stream of traffic with the brake applied.
I'm sure there are many ways to skin this particular cat:
A 555/556/558 and relay solution? MOSFETS?
Heat dissipation could be a factor as the solution will have to be in a watertight project box.
I am playing around with a 556 on a breadboard but finding a solution that will be robust and won't overheat comes down to experience (which is something I lack). Any help would be greatly appreciated.