Bimetallic Switch with Tungsten Contacts

This essential educational tool for physics classes clearly demonstrates how thermal expansion transforms into mechanical movement to control electrical circuits.

Key Features and Specifications

• Premium Materials: The core consists of two welded strips of iron and nickel (Fe-Ni) for precise reactivity.
• Industrial Durability: Tough tungsten contacts resist wear and sparking, ensuring a long lifespan in school laboratories.
• Extreme Temperature Range: Safely operates from –50 to 450 °C, making it suitable for both freezing and open-flame experiments.
• High Visibility: Large strip dimensions (120 × 16 × 1 mm) ensure the bending effect is clearly visible from the back of the classroom.
• Safe Connections: Equipped with standard 4 mm safety sockets on a stable base for quick and secure wiring.
• Overall Dimensions: 120 × 90 × 90 mm.

Quick Experiment Ideas

1. The Classic Thermostat: Heating the strip causes it to bend and open the contacts, automatically turning off a connected light bulb to mimic a real-world iron or kettle.
2. Flashing Safety Light: Wiring a heat source into the circuit creates an automatic loop—the strip heats up, breaks the circuit, cools down, closes the circuit, and repeats.
3. Extreme Cold Reactions: Utilizing the lower limit of –50 °C, cooling the strip with ice or a cooling spray causes it to bend in the opposite direction, proving unequal contraction.