Note to use alternator control, you must also set a PWM Low Side Output to "Alternator Ctrl.". Depending on your alternator you may need a 5v/12v pull-up when using a Wire-In ECU. For our Plug-Ins that require alternator control such as late Mazda MX-5s, the Plug-In base board already has all the pull-ups etc as required. Always use a basemap when using a Plug-In as things such as Alternator control will already be configured for you.


Below you can see the default Alternator settings layout which is under AC/Fan/Alt tab of a default layout in MEITE.



The Status DRO reports the alternator control mode. The Alt. Ctrl Duty (%) is the current PWM drive duty of the chosen Alternator Control pin, and Battery Voltage is the current measured voltage making it to the ECU Ignition input.


Alternator Settings

Mode

Mode can either be PID (which ), Fast Switch (the easiest to


PID Mode
This will use the CL & PWM Params for adjusting the drive duty to reach the targeted battery voltage. Standard PID tuning will need to be followed to set this effectively.

Fast Switch

Fast switch will simply check the battery voltage as often as possible. If the battery voltage is higher than the current target voltage, it will turn off the alternator, or, if it is lower, it will turn on. The end result is a rapidly changing average duty. This is easiest mode to setup, and the most typically used.

Manual Duty

The output duty will always operate at the value entered in the Manual Duty(%) box.


Off
No alternator control, and the chosen output will be set to off/0% Duty.


Inverted Output

This will drive the alternator either normally, whereby when the Duty is 100% the chosen output will be ON, or vice versa. because most ECUs require a pullup which will then INVERT the drive type, usually this is set to Inverted output. If you find using manual mode that more duty=more battery voltage (when the engine is running of course!) then you should set this to normal.

Min RPM

Alternator control will be left at 0% until this minimum RPM level is met, at which point the Start Delay (s) Timer will begin. Once it elapses, then Alternator control will activate.

Charge Mode/Run Mode Voltage/Charge Mode Time

When the engine initially starts, the car will be in Charge Mode, and the system will target the Charge Mode Voltage. Then, after the amount of minutes set in the Charge Mode Time, the system will change to Run Mode and then target the Run Mode Voltage.


Overvoltage Limit and Duty
If the battery voltage goes over the set Overvoltage Limit, the alternator drive duty will go to the set Overvoltage Duty - a basic protection system in case of alternator failure.

PWM/CL (Closed Loop) Params

The PWM Params sets the PID controller when in PID Mode. The drive frequency of the alternator, as well as the Min and Max Duties. The CL Params sets the PID control system as per normal PID tuning.