Abstract: Diodes and switching means as well as an autotransformer connect multiple AC sources of variable frequency and voltage to the utility grid, without first rectifying and thereby transferring the AC input energy to a common DC bus. Instead, the individual positive and negative AC input half waves or parts of those half waves, if and when they occur during a particular time interval, are injected into the positive or negative half wave of the utility AC power directly and respectively. The amount of energy transferred may be controlled by a microprocessor. Assuming the prime mover that generates AC voltages in multiple coils is a windmill, then the required circuitry to accomplish this energy transfer will be physically small enough to allow that circuitry to reside in the windmill itself, and thereby this energy conversion method significantly simplifies the installation of a windmill that uses this energy conversion method.

Abstract: A methodology is provided to reduce data session handoff time between 3G1x and EV-DO technologies for dual mode access terminals. Generally, a dual mode access terminal is communicating with a data network through a base station and a particular packet data service node (PDSN) using EV-DO technology. When the EV-DO technology becomes at least temporarily unavailable, a handoff process is initiated so that communications with the data network may continue using 3G1x technology. During handoff, the access terminal provides an access network identification (ANID) that contains an International Mobile Subscriber Identifier (IMSI). A radio network controller within the base station extracts the IMSI and uses it to select the same PDSN used with the EV-DO technology, which eliminates the need to access an authentication, authorization, and Accounting (AAA) server and perform a re-authentication process.

Abstract: A medium frequency transformer and electronic switches operate together to transfer electric power with variable voltage characteristics to a utility for co-generation purposes. Electric power with variable voltage, such as produced by a wind generator, is converted to variable voltage dc electric power. An inverter converts the variable voltage dc power to ac electric power of medium frequency and then matches the voltage of a utility power grid by using a medium frequency power transformer before injecting the power into that utility power grid. The amount of electric power that is transferred may be controlled, such that an input power source is allowed to operate at its optimum power output.