Abstract: A method of detecting wetness in an accessory jack of a portable communication device (100), such as a two-way radio, is provided. By monitoring an accessory jack detect pin of the radio (104) for a change in resistance (106) that falls within predetermined parameters, a determination can be made (108) as to whether the accessory jack contacts are wet or dry. An alert is provided to a user (110) of the portable communication device that the accessory jack contacts need to be dried.

Abstract: An accessory (102) for a portable communication device (104) includes audio input ports (134) for receiving a differential audio signal having a DC bias (114), a speaker (116) coupled to the audio input ports, and accessory electronics (124) powered by the DC bias. The use of the DC bias of the differential audio signal (114) as a power source enhances the power source capability of the accessory (102).

Abstract: A method of detecting wetness in an accessory jack of a portable communication device (100), such as a two-way radio, is provided. By monitoring an accessory jack detect pin of the radio (104) for a change in resistance (106) that falls within predetermined parameters, a determination can be made (108) as to whether the accessory jack contacts are wet or dry. An alert is provided to a user (110) of the portable communication device that the accessory jack contacts need to be dried.

Abstract: A bi-directional voltage translator (125) has a first port (201) that communicates a signal at a first voltage level, and second port (202) that communicates a signal at a second voltage level different from the first voltage level. A switching circuit, including a bipolar junction transistor (210) and a switch (220), couples both ports (201, 202). The transistor (210) has a collector (211) coupled, via a pull-up circuit (206), to a voltage source corresponding to the first voltage level, and to the first port (201), and an emitter (212) coupled to the second port. The base (213) of the transistor (210) is coupled, via a pull-up circuit (207), to a voltage source corresponding to the second voltage level. Preferably, the switch (220) is Schottky diode or other diode having a forward voltage drop.

Abstract: An apparatus and method for detecting and processing an impedance rheogram includes a constant current source with output electrodes, an impedance signal detecting circuit having detecting electrodes, an ECG signal detecting circuit having detecting electrodes, a signal processing circuit and an output device. The impedance signal detecting circuit and ECG signal detecting circuit respectively, defect the impedance signal and ECG signal, the signal whereby processing circuit divides the impedance signal into cycles according to an R wave sequence, then performs linear interpolating for each cycle and in-phase superposing-averaging for a certain number of cycles, and restores the impedance waveform according to a predetermined number of interpolating points used for each cycle, so as to automatically trace arrhythmia and eliminate respiration interference to the impedance rheogram.