Abstract: To protect software to be transferred to programmable electronic devices, a management system for programmable electronic devices includes a plurality of electronic devices, each identified by at least one unique identification parameter and containing at least one encryption key. The system also includes at least one protected site in which a protected database resides, and in which the unique identification parameter the encryption key are stored for each electronic device. A server is programmed to receive a request for transmission of software from a device and to generate an encrypted version of said software, using the encryption key associated in the database with the unique identification parameter (ID) of the device (57) that has requested the transmission of said software.

Abstract: A resonant power converter is provided with auxiliary circuit branches and control circuitry for switchably coupling the auxiliary branches to resonant circuit components during holdup times. Auxiliary branches are coupled in parallel with any one or more of a resonant inductor, a resonant capacitor, and a magnetizing inductive winding via respective switches. When a holdup time condition is detected in accordance with, for example, a drop in the mains line voltage, the switches are controlled to adjust the corresponding inductance or capacitance for the duration of the holdup time condition or otherwise for a predetermined duration. The power converter in normal operation is configured for high efficiency and in a holdup time operation is configured to produce sufficient holdup time.