Abstract: A device for protecting the electronic circuitry of electrical appliances against damage from unacceptably high voltages. An element is interposed in the power supply paths which limits the application of an externally supplied excessive voltage to a predetermined time interval and which completely interrupts the current flow when the excessive voltage and current causes a heat build-up. This is accomplished by interposing pairs of spaced-apart solder surfaces at at least one point along the current paths to the electronic circuitry. One solder surface of each pair is connected to the power supply and the other to the power consumer. An element is soldered to the respective solder surfaces of the pairs and electrically closes the current path. A mechanically prestressed spring engages the element and reliably separates it from the solder surfaces when the solder melts due to excessive heating.