Power Ignition Management for In-Vehicle Computing

When integrating external devices such as a computer into a vehicle or mobile environment, intelligent power management is a key feature in maintaining operational stability between electrical components. Power ignition management is the controller that manages power distribution to in-vehicle computers by receiving signals when starting the ignition system of transportation vehicles. This is a vital function that allows appropriate handling of an in-vehicle computer’s power supply when starting up and shutting down to prevent the risk of losing sensitive data from sudden power loss or improper computer shutdown.

In-vehicle computers like the ACO series feature a microcontroller unit for power ignition management that receives ignition signals through a serial communication network and controls the different power stages of the computer system. When DC input power is detected from the battery source, the power management process is initiated and begins monitoring for a valid ignition signal before beginning a pre-defined power-on delay timer. Both 12VDC and 24VDC electrical system signals are accepted for different vehicles ranging from consumer automobiles to industrial commercial trucks, heavy machinery, and marine vessels.

After the engine’s ignition system is started and fires a valid signal to the in-vehicle computer, the voltage regulator converts the incoming DC power and provides a stable 12V supply to the mainboard in standby. Once the pre-defined delay timer expires, a boot command is issued to the in-vehicle computer and is now operational. This progression continually monitors signal status in the case of either ignition or computer system failure so that the boot sequence can be restarted until normal operational status is achieved.

Power ignition flowchart diagram for Premio ACO In-Vehicle Computers


When ignition is turned off, the power management system initiates a delayed power-off countdown timer to provide sufficient time for the in-vehicle computer to stop ongoing applications and save critical data before the shutdown cycle is completed. Both delay timers for power-on and power-off are adjustable on the micro-controller allowing for varied lengths of time if necessary for additional data processing after the ignition system is stopped.  Once the in-vehicle computer system is completely shutoff, the power management system returns to a low power idle state that waits for a new ignition signal to restart the process.

Intelligent power management systems are essential for in-vehicle computers to control unpredictable battery voltage fluctuations and protect sensitive computer information when delivering secure and stable power to the main system. In order to combat the harsh nature of vehicular environments, the ACO series offers additional features for reliable and dependable in-vehicle applications.

  1. Intelligent Monitoring and Power Sensing

In the event that the initial ignition phase is abruptly halted during the power-on delay timer, the system is able to cancel the procedure immediately returning the in-vehicle computer to a neutral idle state waiting for a valid and successful ignition signal. Likewise, if the ignition signal is reactivated during the power-off delay timer, the power management system will cancel the shutdown process and keep the main system live and running. This allows the in-vehicle computer to quickly react to sudden reverse changes and ensures the computer is in sync with the vehicle ignition system.

  1. System Power Hard-Off Delay

Once the primary power-off delay timer finishes and the system completes the shutdown process, there is an additional “hard-off” delay that cuts off DC power after a secondary delay timer to ensure the in-vehicle computer doesn’t continue to consume power from the battery. This situation can occur when running applications unexpectedly halt the proper shutdown cycle from finalizing. Without a system power hard-off, the in-vehicle computer can potentially drain the battery of all its power.