| 摘要 |
<p>The invention relates to an over-voltage protection device with failure warning, employed in the electric installations of domestic and industrial consumers. According to the invention, the protection device comprises a logic processing block (1) connected between the neutral and the phase, before an element for disconnecting from the main of a user single-phase circuit (A) consisting of a balanced relay (5) and a voltage measuring block (2) connected between the neutral and an auxiliary earthing (Pa), which is also connected before the balanced relay (5), the output signals of the two blocks (1 and 2) being added by a galvanic separation adder (3), the resulting signal being input to an output stage (4) by means of a light emitting diode (L1) whose lighting means failure, namely long-lasting over-voltage between the phase and the neutral or neutral cut-out.</p> |
