There are numerous varieties of circuit breakers which use different kinds of mechanical techniques to protect electrical equipment from harm. The most simple kinds of circuit breakers which you are sure to be familiar with if you have a house are low voltage rated current circuit breakers such as the ones which are sold in hardware stores and home repair stores under brand names such as Siemens circuit breakers, Cutler Hammer circuit breakers and Square D circuit breakers. These kinds of circuit breakers contain a magnetic solenoid and a lever which is tripped when the current in the solenoid reaches a certain level.

Other kinds of circuit breakers are high voltage, used in a number of applications such as power stations and in electrical transmission networks, and operate on somewhat different principles of design. Thermal blast chambers are used in some of these kinds of circuit breakers and they provide efficiency and reliability with a minimum of moving parts by taking advantage of physics and engineering refinements which have been added over the past few decades. 

No matter what kind of circuit breaker you are talking about, however, the goal in its design is the same – to prevent a circuit from operating once the amperage goes above an accepted level. By keeping the amount of amperage in the electrical current provided to a circuit under control you prevent your appliances from overloading and you keep your home safe, so circuit breakers are a piece of modern electrical technology which everyone needs to live their lives securely.