Load Control Circuit With Ground-Loss Thermal Protection

The invention applies preliminary anti-action by introducing a second switch that preemptively counteracts the harmful voltage buildup at the control connector of the first switch. When the negative potential connection is missing, the second switch detects the abnormal voltage condition and activates to short-circuit the control connector, preventing the first switch from closing and avoiding the subsequent thermal destruction. This proactive measure stops the harmful effect before it can cause damage.

The second switch serves as an intermediary element between the control connector and the negative potential connection. It mediates the abnormal voltage condition by providing an alternative path for the charging currents and transverse currents, preventing these currents from causing excessive voltage buildup at the control connector. The second switch acts as a protective intermediary that isolates the first switch from the harmful electrical conditions.

The invention merges the protective function with the existing switch structure by using a second switch that is integrated into the same control unit housing and shares common electrical connections. The second switch is positioned and connected such that it works in conjunction with the first switch rather than as a completely separate protective device. This merging approach reduces the overall complexity compared to having entirely separate protective systems.

The second switch serves multiple functions: it protects the first switch from thermal destruction, provides an alternative current path during ground loss conditions, and maintains system operation continuity. By making the second switch multi-functional, the invention reduces the need for additional dedicated protective devices, thereby minimizing the increase in device complexity while achieving comprehensive protection.