What type of circuit breaker uses a bimetallic strip for conducting current?

A thermal circuit breaker utilizes a bimetallic strip as the primary mechanism for sensing overload conditions and interrupting the circuit. In this type of breaker, the bimetallic strip is composed of two different metals that expand at different rates as they heat up due to increased current flow. When the current exceeds the predetermined limit, the heat generated causes the strip to bend. This bending eventually trips a switch mechanism, disconnecting the circuit and preventing damage from overheating.

The other types of circuit breakers mentioned do not rely on a bimetallic strip for their operation. Hydraulic magnetic breakers work with a combination of magnetic and hydraulic forces, while digital and smart breakers often utilize electronic components and software algorithms to monitor and respond to electrical faults. These alternative mechanisms do not engage a bimetallic strip to manage current flow, which differentiates thermal breakers in their design and functionality.