A telecommunications optical fiber is secured against intrusion by detecting manipulation of the optical fiber prior to an intrusion event. The system also provides means allowing the heat pump function to be provided by a low-cost, mass-produced, window air conditioner. The pipe-shaped through electrode is utilized as a pipe-shaped electric conductor that extends through the silicon substrate. The power converter system further includes pre-charge circuitry that charges a DC link capacitor located within the power converter system to a desired level prior to providing the power converter system with AC power.