Installing coil

NG

NG

So what am I missing here? I know the typical layout of automotive alternator assemblies (stator through regulator) is with it all grounded to the case as negative. Those should just require electric isolation, and then be able to go positive or negative ground through external wire connections easily enough. At least that's what it looks like to me.

Alternator designers have cleaverly used the alternator case as a heat sink. The diode designers have also cleaverly designed the diodes to use the diode case as 1 side of the diode connection (instead of a wire). This is why modern 12 volt alternators are (a) inexpensive (b) reliable (c) efficent (d) negative ground..... ...Dell

These alternators are connected in a full-wave rectification. In this arrangment, during the positive half of the ac wave, electrons are removed from the positive terminal thru a diode and during the negative half, electrons are added to the negative terminal by a second diode connect in the opposite direction of the first. Alternators are negative ground because way back when someone at GM picked negative ground and it stuck. It could have just as easily been positive groung.

I hope I haven't caused more confusion. It is more complecated than I have discibed but thats it in a nut shell.

My explanation was an attempt in few words to explain why alternators require "negative ground". It really had to do with the eaze of frabication of diodes with their anodes as part of the metalic case for heatsink purposes. And subsiquently using the alternator case as a larger heatsink. It has nothing to do with reversing the alternator wiring to get a positive ground.

On my BMW's, for example, the alternators are "rubber mounted" for vibration reduction (less vibration is a perception of higher "quality" and thus the justification for higher prices) and thus need a seperate "grounding" wire from the alternator case to the engine block. The alternator case is negative.

The second reason for negative grounds, is the NPN transistor power amplifers used in radios. The same problem, heat. Using the radio chassis as heatsink required negative ground since the radio chassis was metal and hung from metalic dashboards with metalic shafts. Otherwize you blow your germainium fuses...er...power transistors.

Thankfully, the semi-conductor industry has come a loooonnnngggg ways since then otherwize, there wouldn't be computers or this N-Board (grin)..... ..Dell

So what am I missing here? I know the typical layout of automotive alternator assemblies (stator through regulator) is with it all grounded to the case as negative. Those should just require electric isolation, and then be able to go positive or negative ground through external wire connections easily enough. At least that's what it looks like to me.