Patent ID: 11923711
Assignee: AMOGY, INC.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 7:
8. A system, comprising:
a positive power supply node and a negative power supply node configured for connection to a load;
a fuel cell coupled between the positive power supply node and the negative power supply node;
a battery;
a solid-state switch, wherein the battery and the solid-state switch are connected in series in a current path between the positive power supply node and the negative power supply node; and
an analog control system; and
wherein the analog control system is configured to generate a control signal that is applied to a gate terminal of the solid-state switch to control activation and deactivation of the solid-state switch to (i) allow the battery to be discharged and supply power to the load when connected to the positive and negative power supply nodes, and to (ii) modulate an amount of charging current that flows in the current path through the battery from the fuel cell to recharge the battery;
wherein the analog control system comprises:
a voltage monitoring circuit configured to determine a voltage level of the battery, and generate a first control signal based on the determined voltage level;
a current sensor configured to sense magnitude and direction of current flow between the battery and the solid-state switch, and generate a second control signal based on the sensed magnitude and direction of the current flow between the battery and the solid-state switch; and
a switch controller configured to receive the first and second control signals, and generate the control signal which comprises a pulse-width modulated control signal with a varying duty cycle, based on the first and second control signals;
wherein the switch controller comprises:
an oscillator circuit configured to generate a pulse-width modulated voltage signal based, at least in part, on the first and second control signals; and
a gate driver circuit configured to generate the pulse-width modulated control signal to drive the solid-state switch, based on the pulse-width modulated voltage signal;
wherein the oscillator circuit comprises:
an operational amplifier comprising a first input terminal, a second input terminal, and an output terminal;
a capacitor having a first terminal coupled to the first input terminal of the operational amplifier, and a second terminal coupled to a DC power supply bus;
wherein the first input terminal of the operational amplifier is coupled to an output of the voltage monitoring circuit and to an output of the current sensor; and
wherein the second input terminal is configured to receive as input a second threshold voltage.