What is the primary function of a soldering iron?

The primary function of a soldering iron is to join electronic components together. This tool generates heat that is used to melt solder, a fusible metal alloy, which is then applied to create electrical connections between components on a circuit board. Proper soldering techniques ensure a reliable and conductive joint, which is essential for the functioning of electronic devices.

In the context of electronic assembly and repair, the ability to effectively join components through soldering is crucial for building and maintaining circuits. A strong solder joint provides mechanical stability and electrical conductivity, enabling the flow of current between various parts of the device.

The other options pertain to different tools or processes in electronics. Measuring electrical current requires a multimeter or ammeter; protecting circuits from overload typically involves fuses or circuit breakers; while displaying electronic signals is done through oscilloscopes or similar devices. Each of these tools serves a distinct purpose that does not involve the act of joining components, highlighting the unique role of the soldering iron in electronics.