- About company
- |
- Products
- |
- News
- |
- Applications
- |
- Contacts

Components and technical solutions for power electronics

Electronic technology current sensors

NCS sensors

1 - Reminder of the key elements

Formulas: | Abbreviations | |

V _{M2} = R_{M2} x I_{S2} V _{M1} = R_{M1} x I_{S1} with 0Ω < R _{M1} or Rwith 0Ω < 350Ω | I_{P} : primary currentI _{PN} : nominal primary currentI _{PMAX} : nominal primary currentI _{S1 }: secondary current at I_{PN}I _{S2}: secondary current at I_{PMAX}V _{S1} : secondary voltage at I_{PN}V _{S2} : secondary voltage at I_{PMAX}V _{A} : supply voltageV _{M} : measuring voltageRS : resistance of the secondary windingR _{M} : measuring resistanceR _{MMIN} : minimum measuring resistance R _{MMAX} : maximal measuring resistance |

**Reminder of the sensor electrical connection2 - Measurement circuit calculation (current output)**

I_{PN} = 2 000A | I_{S1} @ I_{PN} = ±20mA |

I_{PMAX} = 10 000A | I_{S2} @ I_{PMAX} = ±20mA |

R_{M} = 0 - 350Ω (I_{S1} & I_{S2}) | V_{S1} @ I_{PN} = ±10V |

R_{M} > 10kΩ (V_{S1} & V_{S2}) | V_{S2} @ I_{PMAX} = ±10V |

V_{A} = ±15V ... ±24V |

The design of the sensor requires that 2 operating points are respected on the outputs I_{S1} and I_{S2}:• A maximum measuring voltage of 7V d.c. (V _{MMAX} ≤ R_{MMAX} x I_{SMAX})• A maximum output current of ±20mA d.c.. |

The supply voltage does not have any influence on the output signals.

The measured current is greater than I

I

Now determine the value of the resistance R

R

The NCS125-2 sensor can measure a 6000A peak on the signal output I

No special calculation needs to be made. This NCS sensor range supplies a voltage directly proportional to the primary current I