Abstract: A circuit charges and maintains a battery. The circuit includes a microprocessor for receiving a current sense signal and a voltage sense signal. The microprocessor generates control signals for selectively operating the circuit in a charging mode and in a maintenance mode. The circuit includes a current sense circuit for measuring the battery's current consumption and generating the current sense signal responsive to the measured current consumption. The circuit includes a voltage sense circuit for measuring the battery's voltage and generating the voltage sense signal responsive to the measured battery voltage. The circuit includes a waveform generator circuit for receiving the control signals, and operating in response thereto to apply a charging signal to the battery when in the charging mode and to deactivate the charging signal when in the maintenance mode. The charging signal has an oscillating triangular waveform superimposed on a DC bias signal.

Abstract: A method for charging a battery includes measuring the battery's voltage and comparing the battery voltage to a first threshold voltage. The method includes operating the battery in a charging mode if the measured battery voltage is less than the first threshold voltage, wherein operating in the charging mode comprises applying a charging signal to the battery. The charging signal has an oscillating triangular waveform superimposed on a DC bias signal. The method includes measuring the battery's current consumption and comparing the current consumption to a first threshold current. The method includes operating in a maintenance mode if the battery's current consumption is less than the first threshold current, wherein operating in the maintenance mode comprises terminating application of the charging signal to the battery. The method includes measuring, during operation in the maintenance mode, the battery's voltage and comparing the measured voltage to a second threshold voltage.

Abstract: A circuit includes a pulse transformer having primary and secondary windings. An oscillating waveform is applied to the primary winding to induce an oscillating waveform at the secondary winding. A transistor in series with a first resistor is coupled between the secondary winding and the ground. An R-C network formed by a second and a third resistor and a capacitor is coupled to a base junction of the transistor. The R-C network causes a slow, tapered linear pinch off of the transistor's conductance to enable the circuit to output a triangular waveform, which is characterized by a relatively short linear rise time followed by a substantially long linear fall time. The R-C network is coupled to the secondary winding via a first and a second diode, respectively.

Abstract: A method for charging a battery includes measuring the battery's voltage and comparing the battery voltage to a first threshold voltage. The method includes operating the battery in a charging mode if the measured battery voltage is less than the first threshold voltage, wherein operating in the charging mode comprises applying a charging signal to the battery. The charging signal has an oscillating triangular waveform superimposed on a DC bias signal. The method includes measuring the battery's current consumption and comparing the current consumption to a first threshold current. The method includes operating in a maintenance mode if the battery's current consumption is less than the first threshold current, wherein operating in the maintenance mode comprises terminating application of the charging signal to the battery. The method includes measuring, during operation in the maintenance mode, the battery's voltage and comparing the measured voltage to a second threshold voltage.

Abstract: A circuit charges and maintains a battery. The circuit includes a microprocessor for receiving a current sense signal and a voltage sense signal. The microprocessor generates control signals for selectively operating the circuit in a charging mode and in a maintenance mode. The circuit includes a current sense circuit for measuring the battery's current consumption and generating the current sense signal responsive to the measured current consumption. The circuit includes a voltage sense circuit for measuring the battery's voltage and generating the voltage sense signal responsive to the measured battery voltage. The circuit includes a waveform generator circuit for receiving the control signals, and operating in response thereto to apply a charging signal to the battery when in the charging mode and to deactivate the charging signal when in the maintenance mode. The charging signal has an oscillating triangular waveform superimposed on a DC bias signal.

Abstract: A circuit includes a pulse transformer having primary and secondary windings. An oscillating waveform is applied to the primary winding to induce an oscillating waveform at the secondary winding. A transistor in series with a first resistor is coupled between the secondary winding and the ground. An R-C network formed by a second and a third resistor and a capacitor is coupled to a base junction of the transistor. The R-C network causes a slow, tapered linear pinch off of the transistor's conductance to enable the circuit to output a triangular waveform, which is characterized by a relatively short linear rise time followed by a substantially long linear fall time. The R-C network is coupled to the secondary winding via a first and a second diode, respectively.