Method and apparatus to protect an ethernet network by suppression of transient voltage pulses using a plasma limiter

摘要

The invention described here is a circuit protection device based on the principle of a plasma limiter. A plasma limiter uses an electrode such as a very sharp tungsten needle in an easily ionized gas to perform field enhancement using the interference voltage to initiate avalanche breakdown of the plasma. The gas becomes conductive, causing the interference voltage to short-circuit to ground thereby protecting the transceiver Integrated Circuit (IC). This device protects IC's that can be damaged by voltages greater than about 15 volts when damaging voltages have occurred on the wire(s) for a brief time. The damaging voltage creates an electromagnetic field that is enhanced by the sharp electrode thereby causing the easily ionized gas to become plasma and conduct between the wire and grounded electrode. This conduction prevents the damaging voltage on the wire from becoming so great that IC's become damaged. A protection module consists of devices to protect one or many signals in a single module. An implementation of the protection module is a free-standing module that is placed inline with a cable. Also, an implementation of the protection module is a device to be mounted on the printed circuit board or mounted to a panel of the circuit to be protected.