Ethernet Smart Home EMI measurement for CE compliance

eHouseEtherent Measurement of Electromagnetic Emissions EMI – version 2012/2014 CE norms

Smart Home eHouse version Ethernet.
The results of measurements of electromagnetic emission done with Rhode-Schwartz spectrum analyzer(0-25GHz).

eHouse4Ethernet controller are low voltage devices (12V) which implies the need to meet only compliance with EMI standards for CE standard when used in the European Union. There is no need to comply with the LVD (Low Voltage) .

We examined “eHouse Ethernet” controllers into account compliance Elektro-magnetic accordance with EU standards CE .

EthernetRoomManager version 2014 (3,4) have following sources that may generate EMI .

  • switching Power Supply – reduce power consumption of the controller (optional)
  • Ethernet – transmission
  • internal oscillators

The measurements are shown interference and signal levels at critical locations of controller.

Interference generated by the Ethernet Circuit (Transmission Line).

Measurement of disturbance on the Ethernet output before transformer .
Measurements were made for three versions of the electronic system :

  • no EMI filter at the output of transmit Ethernet
  • with EMI suppression filter at the output of transmit Ethernet
  • EMI and RFI filter capacitance forming an LC filter

No filter (EMI version before 2014).
The maximum level of interference ( harmonics are – 67dBm for 200Mhz ) without any EMI filters .
 Smart home eHouse Ethernet - EMI without filters

Electromagnetic Emissions with the full EMI Filter (LC ) .
Measurement of EMI against EMI filter :
The maximum level of interference from EMI filter is – 63dBm for 200MHz .
 Smart home eHouse Ethernet - before TX  EMI filter
The maximum level of interference EMI filter is – 82dBm to 160MHz . What is the suppression of harmonics 21dBm or more than 100 times .
 Smart home eHouse Ethernet - EMI filter for TX

Electromagnetic Emissions with the gland suppression (L) without capacity.
Interference at the level of – 65dBm to 200MHz before gland suppression .
 Smart home eHouse Ethernet - EMI filter before the TX without C
Electromagnetic Emissions with the gland suppression (L ) without capacity . Interference at the level of – Above 120MHz 87dBm ( 22dBm noise suppression over 100 times) .
 Smart home eHouse Ethernet - EMI filter for the TX without C

Interference generated by switching power supply :
Built-in switching mode power supply (optional ) for reducing power consumption in battery-powered systems eg. yachts, campers (reducing the power consumption of about 3 – 4 times) . Operating frequency of about 500kHz .

The signal level at the output of the switching coil (IMP – 28dBm for frequency power supply) .
 smart home eHouse Ethernet - EMI pulse power

The noise level at the output of a switching power supply ( – 75dBm ) – 47dBm attenuation (about 70,000 times) :
 smart home eHouse Ethernet - EMI pulse power output of the power supply

The noise level in the black power ( for the second ( linear ) power supply 3V3 ) – 83dBm . This means additional noise suppression 8dBm or 55dBm (about 500,000 times) .
 smart home eHouse Ethernet - EMI line voltage 3V3 (with double switch mode power supply + line

Noise emitted from the switching power supply 1 cm from the coil ( point maximum) – 65dBm .
 smart home eHouse Ethernet - EMI generated 1cm from coil
The level of the interference maximum of less than – 80dBm 1cm from the controller board above 100MHz .

The level of EMI is housed in a standard CE (European Union) .