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AXB-IRS4 powered by external 12V power supply connection

RajRaj Posts: 53
in AMX Hardware
Hi,

For AXB-IRS4 if we have to add an external 12V power supply, is it necessary that we have to give 12V external power to the second connector(find attachment), instead can I give the external 12V power to the Axlink connector removing the +12V wire which is connected to the NI Controller 12V like how its connected for AXB-REL8 and AXB-RS232++ module.

Comments

  • Marc ScheibeinMarc Scheibein Posts: 896
    You can support the box with external power supply either by the 2-pin connector, or by the AXlink connector.

    But in both cases, make sure that the 12V from the 4-wire AXlink will NOT have ANY connect to the 12V of the external psu. This means the 12V from AXlink 4-wire should not be in the 4-pin Phoenix connector at all.

    GND of AXlink and external psu must be put together, to have the same Gnd level.
  • ericmedleyericmedley Posts: 4,177
    Marc Scheibein wrote: »
    You can support the box with external power supply either by the 2-pin connector, or by the AXlink connector.

    But in both cases, make sure that the 12V from the 4-wire AXlink will NOT have ANY connect to the 12V of the external psu. This means the 12V from AXlink 4-wire should not be in the 4-pin Phoenix connector at all.

    GND of AXlink and external psu must be put together, to have the same Gnd level.

    Oddly enough, hooking two power supplies of this nature together doesn't really hurt anything. the presence of them in parallel only creates a little heat at both voltage regulators in the power supplies. This is due to the fact that the long run of wire between the two power supplies is essentially a resistor. But, two or more 12Volt power supplies running in a parallel circuit still makes 12 volts. It just ups the overall amp load of the circuit as a whole.

    Two 500ma supplies will equal 1000 ma minus loss due to resistance and heat.


    That's not to say I would do it. If one supply failed, the other would burn up rapidly. It's just kind of a curiosity.
  • DHawthorneDHawthorne Posts: 4,584
    The problem with two power supplies is the potential of a differential in the voltage causing a current flow between them. That would be what is causing the reported heat generation in the rectifier circuits, and would probably decrease the lifespan of those circuits if the differential was too great. It's recommended if you use an external supply to disconnect the V+ line from the Axlink buss.
  • ericmedleyericmedley Posts: 4,177
    DHawthorne wrote: »
    The problem with two power supplies is the potential of a differential in the voltage causing a current flow between them. That would be what is causing the reported heat generation in the rectifier circuits, and would probably decrease the lifespan of those circuits if the differential was too great. It's recommended if you use an external supply to disconnect the V+ line from the Axlink buss.

    Yeah, I would never recommend it either. It's more just the idle musings of an engineer...

    I guess, I've ran into a few techs who were trying to make a 24 volt power supply buy connecting two 12 volts together. I seem to have a hard time explaining that two don't make double the voltage.

    I probably shouldn't have posted my idle musings.

    Oops, I did it again.. :~>
  • RajRaj Posts: 53
    Thanks guys.
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