Input protection circuit

Abstract

A voltage clamp protection circuit to protect against overvoltage conditions where there is insufficient current to blow a fuse. The voltage clamp protection circuit includes a voltage clamp and a thermal cutoff. The voltage clamp clamps any overvoltage to a clamping voltage. If an overvoltage condition persists for too long the voltage clamp dissipates a sufficient amount of heat to activate the thermal cutoff creating an open circuit that protects the rest of the circuit. The voltage clamp protection circuit may be used in combination with a variety of other protection circuits to provide increased protection.

Description

technical field [0001] This application claims the benefit of US Provisional Patent Application 61 / 048,036, filed April 25,2008. Background technique [0002] The present invention relates to an input protection circuit suitable for use in an inductively coupled circuit or substantially any other type of circuit. [0003] Inductive coupling has many advantages. One advantage is that inductive coupling provides additional opportunities for simple and efficient interoperability, where devices can be used interchangeably. However, circuit design that "cuts the cord" and enables interoperability may render the circuit sensitive to third-party systems. That is, the magnetic field generated by the third party system may negligibly energize and provide undue energy to the secondary coil in the remote device. In some cases, power from these third-party sources can be disruptive. As wireless power becomes more common, so does the amount and variety of third-party magnetic fields....

AI Technical Summary

Problems solved by technology

However, if the overvoltage condition persists for too long, the TVS may collapse, which can cause the circuit to be damaged or destroyed

Images