초록 ▼

An arc suppression circuit for a switch carrying a load current includes a MOSFET having a drain connected to a first contact of the switch and a source connected to a second contact of the switch. A biasing capacitor is coupled at one end to the drain and at another end through a damping resistor t

An arc suppression circuit for a switch carrying a load current includes a MOSFET having a drain connected to a first contact of the switch and a source connected to a second contact of the switch. A biasing capacitor is coupled at one end to the drain and at another end through a damping resistor to the gate, such that when the switch contacts are opened, the interrupted load current passes through the biasing capacitor to charge an inherent gate-to-source MOSFET capacitance for turning on the MOSFET and shunting the load current around the switch. A biasing resistor, connected between the gate and the source of the MOSFET, subsequently discharges the gate-to-source capacitance, turning off the MOSFET and terminating the shunted load current after the contacts of the switch have separated by a distance sufficient to preclude arcing. A zener diode, having its cathode connected to the gate of the MOSFET and its anode connected to the source of the MOSFET, quickly discharges the biasing capacitor when the switch contacts are reclosed.

대표청구항 ▼

An arc suppression circuit used with a switch carrying a load current, said switch having first and second contacts, said circuit comprising: a MOSFET having a drain, and means for coupling the drain to said first contact of said switch, said MOSFET having a source, and means for coupling the source

An arc suppression circuit used with a switch carrying a load current, said switch having first and second contacts, said circuit comprising: a MOSFET having a drain, and means for coupling the drain to said first contact of said switch, said MOSFET having a source, and means for coupling the source to said first contact of said switch, said MOSFET having a source, and means for coupling the sourcre to said second contact of said switch, said MOSFET also having a gate, and an inherent gate-to-source capacitance, capacitor means for charging said gate-to-source capacitance when said first and second switch contacts are opened and are at differing potentials such that the MOSFET turns on, said MOSFET shunting the load current around said switch contacts, and resistance means for discharging said gate-to-source capacitance such that the MOSFET turns off after it turns on thereby terminating load current shunting.