Posted by Joe Cimoch from 4.17.137.199 (?) on Wednesday, April 03, 2002 at 9:59PM :
In Reply to: Re: 1 wire alternator question posted by Keith in Washington from 207.46.137.9 (tide09.microsoft.com) on Wednesday, April 03, 2002 at 1:22PM :
From the Powermaster FAQ:
I noticed that my Powermaster one wire alternator has to be “revved up” to get the alternator to come on. Why?
A one wire alternator has a turn on point (sometimes called “cut in”, which is typically 1200 engine RPM’s). This is the speed where the internal sense circuitry connects the battery to the voltage regulator, thereby turning the alternator on. Once the voltage regulator turns on, the alternator will remain on and charging until the engine comes to a complete stop. If the engine idle speed and pulley ratio combination do not allow the alternator to come up to this point during starting, the engine will have to be revved up to turn the one wire alternator on. The sense circuitry in the one-wire regulator can be bypassed to excite the alternator as soon as the ignition switch is turned on. This is called three-wire operation. This means the alternator will not be dependent on reaching a certain turn on RPM.