Alternator: Voltage or current limited with high load?

[goboatingnow]

I noticed confusion in some of the other posts, where some folks are referring to voltage regulators as just the function of actually regulating the voltage, as opposed to the additional function of limiting the current. Those functions are entirely different. The Balmar and other external regulators can be set to do both functions. So when someone says "voltage regulator" we have to distinguish: are they talking about all the functions that a good external alternator regulator device may provide, or are they talking about just the actual voltage regulation function provided by that device.

err, there is no such thing as an alternator regulator . it is in practice a voltage regulator in that that is what the electronics are regulating \

Remember ohms law always applies , so if you fix voltage , current must be allowed to vary and equally if you fix current, voltage must be allowed to vary

In reality , with a imperfect voltage source , such as a alternator , all regulation is done effectively by voltage control, at max current the alternator , not being a perfect voltage source, will be effectively limiting its voltage against its internal output impedance , hence NO regulation will be occurring, at other operating points , the voltage regulator ( if it has a current sensing function ) , will in fact reduce voltage to ensure a given is only sourced by the load

IN teh case of ordinary voltage regulators , as the battery impedance rises as it charges , current inherently falls and as with ohms law, voltage rises . until voltage regulation takes place and in effect the alternator lowers its output voltage so as to prevent the output voltage rising too high , It does this by reducing the field energy