RECORDER OF DOUBLE EARTHING IN ISOLATED NEUTRAL CIRCUITS Russian patent published in 2008 - IPC H02H3/16 

FIELD: electrical engineering.

SUBSTANCE: recorder incorporates a power source, a three-phase power circuit with two phases connected to current transformers. The secondary circuits of the said transformers include trans-reactors connected, by secondary windings, with a multi-arm diode bridge with its input being connected to the first capacitor, connected in parallel, and the first resistor shunted by a chain made up of the second capacitor, second resistor and the first reactor, all connected in series. The third capacitor, an output component, voltage transformer with an open-triangle winding connection, single-phase diode bridge are connected to the aforesaid winding, all connected in parallel. The third resistor and the fourth capacitor, connected in parallel, are connected to the single-phase diode bridge output. The fourth resistor and fifth capacitor, connected in parallel, are connected, via the first diode, to the single-phase diode bridge output. Note that the second back-to-back diode and the second reactor connected to the AND element first input are connected in parallel to the first diode. The AND element second input is connected to the first reactor output and the said element output is connected to the output component.

EFFECT: higher reliability of power supply, higher electrical and fire safety.

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