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Old September 6th, 2021, 04:30 PM   #8428
DannoXYZ
ninjette.org certified postwhore
 
Name: AKA JacRyann
Location: Mesa, AZ
Join Date: Dec 2011

Motorcycle(s): CB125T CBR250R-MC19 CBR250RR-MC22 NSR350R-MC21 VF500F CBR600RR SFV650 VFR750F R1M ST1300PA Valkyrie-F6C

Posts: A lot.
MOTY - 2018, MOTM - Nov '17
Quote:
Originally Posted by Triple Jim View Post
You can read the pros and cons of a series (pass) regulator vs. a shunt regulator from various sources on the web. It sounds bad to have a shunt regulator shorting the alternator's output to ground, but it's a permanent magnet alternator. When its output is shorted to ground, very little power is actually produced, since power = Volts x Amps and volts is near zero at that time. Since it's a PM alternator, the output current is limited even when shorted.
This is only true if you short AC coils to ground. However in way circuit is arranged, AC coil goes through rectifier first. Then output of rectifier is grounded, not the coil. So AC coil is never shorted to ground. In which case, AC coils are loaded 100% at all times.



This can be verified easily via temp-probes on stator-cover.
1. Regardless of load, stator is full-temp regardless if bike is idling or driving 300w lights.
2. However, RR is hotter at idle (dumping 250w to ground) and cooler when driving 300w lights (dumping 0w).

Also notice that shunt-circuit RR uses linear-regulator that divides voltage, not current.
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