CIRCUIT TO MONITOR THE VOLTAGE OF A SELECTED DC POWER SUPPLY IN A REDUNDANT POWER SUPPLY SYSTEM.

摘要

Two power supply devices (GR1, GR2) are provided, one (GR1) of which supplies the loads (MC1 to MCn), while the other (GR2) is used as a spare for the failure of the first device. The two power supply devices are at the same reference potential on the output side. The positive terminal of the spare power supply device (GR2) is connected to the anode, and the positive terminal of the supplying power supply device (GR1) to the cathode of a diode series circuit (D2 to D5). Only when the voltage of the supplying power supply device falls below that of the spare power supply device (GR2) by a minimum amount, defined by the forward voltage of the diode series circuit (D2 to D5), does a voltage drop occur on the diode series circuit which is sufficient to switch on an electronic switch (OPK0). In this case, the electronic switch triggers a disturbance report (SS) and, via an electromechanical switch (UR) permits the power supply devices to switch over. This electromechanical switch itself switches a latching circuit and ensures that the disturbance report (55) is maintained even after the power supply devices have switched over. IMAGE