Patent for Sale:

Circuit Breaker Based on Leak Current Detection    

This technology relates to a circuit breaker apparatus and method based on resistive leakage current detection.


The present apparatus and method accurately detect resistive leakage current that arises from insulation resistance, which is a main cause of short circuit-caused fire, electric shock and other hazardous situations. The leakage current detection is done without momentarily turning off the power supply of the system. The present technology provides a breaker, relay or the like that shuts down the system when the leakage current exceeds a certain threshold.

Primary Application of the Technology

Circuit breaker for homes and industrial usage.

Competitive Advantage

The present technology provides a circuit breaker that operates by directly detecting resistive leakage current. This scheme is novel in the breaker technology. A precise breaker operation is thus achieved, reliably preventing an electric shock, fire and other hazardous situations.

South Korea recently revised their safety standards by setting the leakage current threshold to be 6mA . The present technology was devised to meet such tough standards.

Many other countries are expected to follow suit to the Korean standards in the near future, and thus will end up replacing their circuit breakers with those that can meet the new safety standards.

A quick estimate based on the number of breakers used in private homes in Taiwan, Australia, China, Europe, India, Sri Lanka, US, Russia, Hong Kong, and South Korea shows that the gross sales can be as high as $6B. This number will jump to more than $10B when industrial usage is added to the estimate.

The seller may consider selling these patents individually.

Patent Summary

U.S. Patent Classes & Classifications Covered in this listing:

Class 361: Electricity: Electrical Systems And Devices

Systems or devices which provide safety and protection for other systems and devices; control circuits for electromagnetic devices and non-electromagnetic-type relays. Systems or devices which discharge, or prevent the accumulation of electrical charge on or in an object or material; circuits for charging objects or materials. Systems for generating or conducting an electric charge. Systems which process electrical speed signals. Circuits for reversing the polarity of an electric circuit. Systems which cause the ignition of a fuel or an explosive charge. Systems and processes for demagnetizing a magnetic field. Transformers and inductors with integral switch, capacitor or lock. Electrostatic capacitors, per se. Housings and mounting assemblies with plural diverse electrical components. Electrolytic systems and devices.

Subclass 42: Ground fault protection
Subclass 44: With differential sensing in a polyphase system

Class 324: Electricity: Measuring And Testing

This is the residual home for all subject matter, not elsewhere classified, relating to the measuring, testing (or sensing) of electric properties, (e.g., determining ground resistivity, determining frequency of an alternating current, determining kilowatt hour demand), or the measuring, testing or sensing of nonelectric properties by electric means (e.g., determining moisture, a nonelectric property, by measuring conductance with a resistance bridge; determining speed, a nonelectric property by use of an electric tachometer).

Subclass 551: Insulation

European Patent Classes & Classifications Covered in this listing:


MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES . Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere.


EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS . Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection .