EMU1node – base module

Energy management unit base module for interfacing the power line

» Posted on 24. Jul 2012

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EMU1node Carrier Board


EMU1node Carrier Board assembly (Top/Bottom)



EMU1node – Carrier Board is an electronic module for a host system, offering required interfacing to 110V/220V AC-power lines to control and monitor any load up to 2500W (~12 Amp) using MOSFETs.

The EMU1node – Carrier Board is designed to carry the ACU3 or ACU4 modules as its host. The carrier serves the host with power directly from the AC-power mains. Customer may decide to use their own host boards in combination with this carrier board.  Since the main controlling and monitoring is designed to be over Bluetooth (wireless), no galvanic isolation is implemented between the host and the mains of the AC-power line. The EMU1node – Carrier Board contains:

  1. Non-isolated 12V and 5V power supply (≤5W)
  2. A pair of 650V / 15A N-channel MOSFET for switching the main power
  3. Hardware implemented fault detection and release algorithm (electronic fuse)
  4. Li-Ion Battery interface
  5. Add-On socket for ACU3 / ACU4 Type hosts
  6. Three sets of RGB LEDs for status signalling
  7. Current and Voltage sensor interfaces to host for power metering
  8. PCB integrated “Schuko”  footprint for EU plugs or “NEMA” footprint for US plugs





Printed Circuit Board (PCB) Design

The PCB is built on 2 layers with 70µm Cu on each layer. The used material for the PCB ist FR4. The thickness is 1.6mm. Minimum Cu-Cu gap is 0.2mm and all tracks on the PCB are ≥ 0.2mm. The smallest drilling diameter is 0.4mm and there are 115 drills on the board. All components are on one side of the board.




The assembled PCB has a total height of 50mm.
All units are in millimeters. 



 Electrical Interface



Host Interface

Pin# Pin-Name Type Descriptions
1 VBAT Power One-Cell Li-Ion battery positive terminal to host
2 +5V Power Main power supply to the host
3 LED (Blue) Input Blue LED driving signal from host
if ≥700mV then LED=ON, ≤400mV then LED=OFF
4 LED (Green) Input Green LED driving signal from host
if ≥700mV then LED=ON, ≤400mV then LED=OFF
SCL N/A I2C bus clock line from host (not used)
SDA N/A I2C bus data line from host (not used)
+3V3 N/A Regulated 3,3V power from host (not used) 
auxVoltSens N/A Auxiliary voltage sense to host (not used)
GND Power Power ground
10  VoltSens Output Main power voltage sense signal to host
11  Fault OpenCollector Low-active signal to host
12  VoltageCross Output Main Power voltage zero-crossing signal to host
13  csrAIO0 N/A Analog I/O signal from host 
14  LED (Red) Input Red LED driving signal from host
if ≥700mV then LED=ON, ≤400mV then LED=OFF
15  Load1(ON/nOFF) Input Main Power switching control by on board MOSFETs 
16  Load2(ON/nOFF) Input Control signal for secondary optional load control 
17  extPWRShutDown Input Disable on board power supply
18  CurrentSens Output Main Load Current sense signal to host
19  GND Power Power Ground 
20  Vbatchg Passive Host SMPS bypass capacitor for battery charging voltage 


Optional Interface

Pin# Pin-Name Type Descriptions
21  VBAT Power Connect to external Li-Ion battery positive terminal
22  GND Power Connect to external Li-Ion battery negative terminal 
23  VDD Power On board non-isolated SMPS DC +12V output (e.g. to relais coil) 
24  AUX Output Driving signal for second load control (e.g. relais coil) 
25  GND Power Power Ground 


Off-Line power Interface

Pin# Pin-Name Type Descriptions
26  EARTH Power Main Poer Earth signal 
27  NULL OUTPUT Power Main Power NULL signal to the load 
28  PHASE OUTPUT Power Main Power PHASE signal to the load 
29  NULL INPUT Power Main Power NULL signal input 
30  PHASE INPUT Power Main Power PHASE signal input 

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