Patent ID: 7498691

Claim:
In combination: an immersion vibrator, including: a vibration bottle that houses an electric motor and an imbalance, the imbalance being driven by the electric motor, a switch housing connected to the vibration bottle and bearing an on-off switch that is electrically coupled to the electric motor, and a first mains plug configured to plug into a socket of at least one of 1) a special voltage network and 2) a stationary frequency converter so as to receive a special voltage and to supply the special voltage to the electric motor via the switch; and a frequency converter, including: a mobile converter housing; a converter circuit that is arranged in the converter housing and that converts an electrical mains voltage to the special voltage, the mains voltage having a frequency level lower than the special voltage; a second mains plug configured to be plugged into a public mains system so as to supply public mains power to the converter circuit; a plug socket which is fed with the special voltage from the converter circuit, wherein the first mains plug plugs into the plug socket; and a manually operated changeover switch having a first position so as to cause the converter circuit to convert the mains voltage received at the second mains plug of the frequency converter to the special voltage for communication to the second mains plug, and a second position so as to cause the converter circuit to pass through the special voltage received at the second mains plug of the frequency converter to the first mains plug without modifying the special voltage.