Generator Regulators - BOSCH: Description
Bosch manufactures both a two-unit and a three-unit regulator for six and 12 volt systems. In 1973 only the two-unit regulator was made. Two-unit regulators consist of a voltage regulator and a cutout relay. Three-unit regulators incorporate a current regulator in addition to the voltage regulator and cutout relay. The voltage regulator on all Bosch regulators is a two stage unit operating on a double set of contacts. A regulating element of semi-conductive material called "variode" is incorporated in some models. This variode senses temperature variations in the cable due to amount of charging current and ambient temperature.
CAUTION:
Before putting generator and regulator into operation, they must be polarized. To polarize generator, momentarily contact lead from positive post of battery to "D+" terminal on regulator (with belt removed). Never polarize by connecting terminal "B +" (on regulator) to terminal "D+" on regulator. Damage may result to regulator, and generator.