Transistor-PTC circuit protection devices

摘要

A circuit protection device for protecting an electrical load includes a three-terminal switch element such as a bipolar, or junction or metal-oxide-semiconductor field effect, transistor and a positive temperature compensation (PTC) resistor. In several embodiments the PTC resistor is in series with the current-carrying electrodes of the transistor. In other embodiments the PTC resistor, or a second PTC resistor, is connected to a control element of the transistor. Both DC and AC load-protection circuits are described.