1990-92 Mercury 175s with 16 amp stator Voltage regulator and separate. rectifyer

Have replaced the rectifier now get good tac signal - tested dead - engine starts up immediately
battery shows 12.9 on volt meter after sitting over nite with no charge. Crank
her up and volt meter starts creeping up to over 15 with no load
Take rpms to 1500 and vm goes over 16. Checked out new voltage regulator
approx $500. Found numerous CDI voltage reg/fectifers for much much less.
Can I convert the system or am I stuck with a $500 part - all suggestions appreciated.

There's nothing magical or mysterious about the engine's battery charging system. You have 4 diodes in a bridge configuration producing full wave rectification. These positive "half cycles" are applied to a regulator basically consisting of a variable resistor in series with the current output, that output being monitored and feeding back information to the variable resistor....a silicon transistor.

Find yourself something designed to rectify 50v or more AC sine waves and handle 20 or so Amps of current, investigate any heat sinking requirements and plug it in.

Thanks - figured it out - appreciate a very good explanation of the system. I mainly just didnt want to fork over the $500 fora new voltage regulator. Found that CDI has a regulated rectifier that accomplishes
what my old voltage reg and rectifier were doing. Cost will be 140-150. Much better. I will gladly eat the 30 I paid for the rectifier.