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Replacing voltage regulators in iS engines?
Posted: Thu Jul 08, 2021 4:02 pm
by fatsportpilot
Does anyone know if it's possible to replace the regulator rectifiers in the 912iS engine with a different brand like Silent Hektik? I don't like shunt regulators.
I know you can do that with the 912ULS but the 912iS regulator rectifiers are a little different.
Re: Replacing voltage regulators in iS engines?
Posted: Tue Jul 20, 2021 8:58 pm
by fatsportpilot
I know that the generator in the iS is three phase not single phase, so I'd need a three phase full-wave rectifier, so the regular aftermarket replacements that work on the ULS wouldn't work on the iS. Unless there is an easy way to convert a single phase rectifier to a three phase rectifier.
Re: Replacing voltage regulators in iS engines?
Posted: Wed Feb 15, 2023 8:05 pm
by fatsportpilot
My beliefs were wrong. I didn't like shunt regulation because it shorts the generator windings to drop voltage, and I thought that meant it used the windings as a resistive "dump load", so there would constantly be 600W dissipated at all times (split up between windings, regulator, and other loads). But I was wrong. When current is shunted back to the generator, the inductance actually unloads the generator.
The infamous inefficiency of shunt regulators at low loads is actually because they don't perfectly short the windings. The current has to flow through SCRs first (diodes that can be turned on or off) which drop 1-2 volts and heat up.
A shunt regulator using MOSFETs and synchronous rectification will actually put less load on the stator windings than a high-efficiency switching regulator!