Input Voltage Source

[mquigley@geosyntec.com]

I would like to use an alternative power source for my iobridge due to requirments of related equipment in the housing I am wokring on and do not want to have two power suppiles.  Looks like the 317MB voltage regulator with the configuration on the PCB ouputs about 5.3VDC regardless of input voltage (up to 40VDC.)  Is it thus fine to use a 19.5 VDC 3A power supply?

[jason]

I almost certain that connecting an IO-204 module to 19.5v would destroy it.  It would probably ruin anything that was connected to it at well since the same power is distributed to the I/O channels.

The input voltage must be 5v (or very close to it).  The microcontroller on the IO-204 PCB can only operate within the range of 5.5v to 4.2v.  The voltage regulator you see on the PCB is to step down the input voltage to 3.3v for one of the chips.

You may be able to use something like this to get 5v out of the power supply you have:
http://search.digikey.com/scripts/DkSearch/dksus.dll?lang=en&site=US&WT.mc_id=hp_go_button&KeyWords=pt5101n-nd&x=0&y=0

   

[mquigley@geosyntec.com]

I see that now. I misstraced one of the leads on the PCB. I now see that the 5VDC  goes directly to the PIC (amongst other places like the IO boards).  I will need to put another regulator before the input.  Thank you.