In a power supply system, a controller is electrically connected with a plurality of switching elements of a multiphase inverter. Packets, such as VoIP packets, are transmitted on the uplink and downlink using respective semi-persistent resources. Alternatively, when R1 is hydrogen, the biologically active agent can be a pharmaceutically acceptable salt of the compound of Formula I. The tongue cleaning electrode enables a current flow into a user’s tongue during operation. A third amplifier, which includes a programmable current mirror input stage, is configured to receive the first differential output signal from the second amplifier through the current mirror input stage and to output a second differential output signal.