DESIGNER’S HANDBOOK 4189350049C EN
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If a 10V Zener diode is used resulting in a 14V supply to the current loop. It will be possible to connect 5 XDi units
(7V + 5 x 1.3V = 13,5V) in series and they can all have the dimmer voltage connection as shown above.
Note: If the power source is including a 24V emergency battery with a charger, which means that the voltage range
can be between 18V and 29V this solution cannot be used.
5.6.7.2.3
Alternative 3 - how to solve the common mode problem
The above system will work if the current loop and dimmer circuit is connected to 2 separate AX1 modules, since
the two modules are galvanic separated the problem with common mode voltage is solved.
But please note that this solution will not be possible for XDi 96 (only one extension slot) and that the DEIF
standard rudder library for XDi 144 and XDi 192 does not support this configuration either, so a customized library
will be needed.