Solid state fuse
AssigneeInternational Rectifier Corporation
InventorBruno C. Nadd
Life of this patent
Estimating the term…
Abstract
A solid state fuse type protective circuit is provided in which a series MOSFET is connected in series with the load and its voltage source and a shunt MOSFET is connected in parallel with the load. A control circuit turns the series MOSFET on and the shunt FET off under normal operation; and turns the series FET off and applies a turn on signal to the shunt FET under a fault condition. An indicator LED is connected across the series FET and turns on when the series FET turns off.
Claims12
A solid state fuse for an electrical load powered from a voltage source and comprising:
- a series controllably conductive device connected in series with said voltage source and load and having a control electrode energizable to turn said series device on or off;
- a shunt controllably conductive device connected across said load and having a control electrode energizable to turn said shunt device on or off;
- a control circuit connected to said control electrodes of said series and shunt devices and a fault sensor coupled between said load and said control circuit and producing an output signal to said control circuit in response to a fault condition in said load;
- said control circuit producing control output signals to turn said series device off and said shunt device on in response to a predetermined fault condition.
The method of protecting an electrical load against fault conditions comprising:
- the opening of a normally conductive first MOSFET device in series between the load and an energizing circuit therefor in response to a fault condition, and enabling the closing of a normally off second MOSFET which is in parallel with the load in response to the appearance of a voltage across the load after the first MOSFET opens, thereby to permit the safe examination and correction of said fault.
Dependencies are inferred from the claim text.