Posted on November 22, 2016
The newer Ford Mustangs have sequential brake and turn signal lights that really adds to the car. Unfortunately, my '09 Mustang does not have this, for a modest price of $130, I could buy a kit to give my car this great feature, but that is too much for something so simple. So I dug into this problem and designed an add-on board to give my car sequential lights.
The simplest electronic design would just be a timer to delay the next light from coming on. I could have (and probably should have) used the 556 dual timer to control the left and right, but I opted for what I had on hand, and that was the 555 timer.
A car's running voltage is around 14V and a brake light is around 27W. This is an amp load of around 1.9. This is too much for the maximum output for a 555 timer which is 200mA (0.2A). A PNP power transistor rated for this will work nicely to control this load.
27 Watts = 14 Volts x (1.9 Amps)
Below is the PCB I designed. Due to higher amp load and the fabrication restrictions I have, the traces are larger than normal.
I used the age old method of "toner transfer" to make this PCB. A very fast and easy was to make descent boards.