Patent ID: 8750534

Claim:
A power injection circuit to provide electric power to an aviation headset, the power injection circuit comprising: an aircraft intercom system (ICS) interface for connection to an ICS, the ICS interface including at least a voltage (VCC) connection, a microphone high (mic-high) connection, a microphone low (mic-low) connection, and a system ground (system-gnd) connection; a headset interface comprising at least one connector to receive at least one connector of the headset; an alternate microphone low (alt-mic-low) conductor coupled to the headset interface to conduct a signal of a microphone of the headset; a system ground conductor coupled to the ICS interface and the headset interface to couple a headset ground to the system ground connection; a first voltage source coupled to the alt-mic-low conductor to create a DC voltage differential between the alt-mic-low conductor and the system ground conductor; an alternate push-to-talk (alt-PTT) conductor coupled to the headset interface; and a PTT separator coupled to the alt-PTT conductor to monitor the PTT conductor, and to signal the first voltage source to enable the first voltage source in response to detecting a triggering resistance between the alt-PTT conductor and the alt-mic-low conductor.