Broadly, the ZM5 regulator consists of a timer block, voltage comparison logic and a MOSFET output stage.
The timer block is responsible for overseeing the transition between the absorption and float stages, and is factory set from 80 to 100 minutes according to your battery capacity.
The voltage comparison logic continuously monitors the battery voltage and compares it to the voltage level you have selected with the adjustment control. Improved JFET-input operational IC has a lower Input Bias Current and high slew rates providing better overall performance.
If it detects that the battery voltage has fallen below your set point, the output MOSFET stage will be turned on to increase the field current to the alternator.
Once the voltage level has been raised back to your setting, the field current is disengaged. Hysteresis is built into the comparison logic to ensure the feedback loop remains stable.
A slight amount of current is held to ensure that the ignition light does not come on
Control of reverse polarity is also built in to the new design. Better adjusting potentiometers are sealed and provide a more accurate setting
Any type of alternator can be run by this regulator, providing field current draw does not exceed 20 amps continuous or 26 amps intermittently. Most alternators only draw 1-3 amps max.
Field Brush Configuration.
There is no performance difference or advantage is more an alternator manufacturers choice. Some alternators are best suited to P type but the majority are N type.
The ZM5 N is a negative brush control system, this means that the positive brush requires power at all times and the theory is we control the negative brush which controls the output of the alternator as per the setting on the ZM5,
The ZM5 P is a positive brush control system, this means that the positive brush is the field control and the negative brush is earthed.