Stahl Rectifier
This is a unique rectifier, in which the alternating current is rectified by being sent through a commutator which is rotated by a small alternating current motor, similar to the way the alternating current generated in the armature of a direct current generator is rectified in the commutator of the machine. The Stahl rectifier supplies the alternating current from a transformer instead of generating it as is done in a direct current generator. Brushes which bear on the commutator lead to the charging circuit.
The Stahl rectifier is suitable for the larger service stations. It gives an interrupted direct current. It is simple in construction and operation, and is free of delicate parts.