Abstract: A single transistor dual mode crystal oscillator circuit is described which may excite more than one C-mode frquency in a crystal simultaneously such as the fundamental, used as a clock driver frequency, and a beat frequency between the third harmonic and the third overtone frequency, simultaneously. Each signal is thereafter passed through a separate amplifier means to further enhance those outputs for use.

Abstract: The physical and electrical condition of electrochemical cells of a battery s monitored on a continuous basis so that corrective action can be taken before explosion and/or venting occurs by a method including the steps of:(A) coating the electrically conductive shell of each cell of the battery with a thin non electrically conductive layer,(B) applying a sensor stripe over the non electrically conductive layer so that the sensor stripe does not make electrical contact to the shell of the cell,(C) connecting leads to the sensor and then coating the sensor with a protective layer, and(D) connecting the sensor leads of individual cells of the battery into an electrical series circuit, the remaining leads of the series sensor circuit being connected to an alarm/control network that monitors the conductivity of the series electrical path.