Inventors:
Glenn E. Eiden - New Haven IN
International Classification:
H02J 700
Abstract:
A circuit for regulating the charging of a storage battery by a photovoltaic array includes a relay switch connected between the storage battery and photovoltaic array. An operational amplifier connected as a differential amplifier with a low-pass filter has one input terminal connected to the storage battery through a resistive divider and the other input terminal connected to a voltage reference. The output of the operational amplifier is connected to the input of a transistor amplifier having an output connected to the control coil of the relay switch. When the battery voltage exceeds a predetermined setpoint, as presented to the input terminal of the operational amplifier through the resistive divider, relative to the voltage reference, the operational amplifier and transistor amplifier de-energize the control coil of the relay switch, thereby opening the relay switch and disconnecting the photovoltaic array from the storage battery. As the voltage of the storage battery falls below the setpoint, the state of the relay switch is reversed and charging resumes. The low pass filter prevents the relay switch from changing state at a frequency greater than a preselected frequency.