The automatic switching of lights

Assumptions:

• automatic switching of parking and passing lights a few seconds after starting the car
• automatic shut-off lights after turning off the ignition
• the smallest possible number of modifications to the original installation of the car
• no interference with the original switches
• reliability
• ability to disable the system

The system was designed in a free Yenka software. It was very comfortable seeing all tensions in the system, also well and easy to change the value of the item.
The system acts as a comparator, which compares the voltage at the Zener diode 8,2V with the voltage on the resistor divider. When the voltage rises above the voltage in the diode (about 8,11V), there is high state at the output of the amplifier appears and the relays are activated.
The whole was placed on a universal board.
Disabling the system (or rather the ability to disable the lights when the ignition is on) is done by switch, through which the power of contactor coils flows. The system after ignition takes 7mA, and after switching on the system (after ignition) about 90mA.



Link to original thread (useful attachment) – Układ automatycznego załączania świateł