Voltage Monitor

[zedman]

This post is really a sanity check - your input is needed.

I wish to monitor the status of my household power. Is it on, or is it off (ie. am i experiencing a blackout).

I discovered a post on this forum that suggested an easy way to achieve this was to use a +5VDC plug-pack (wall-wart) - connect the +5VDC output of the plug-pack to the Digital Input of the IoBridge, and the Ground of the plug-pack to the Ground of the IoBridge. (with a 1K ohm resister between the +5VDC and the Ground).

If house power was present, then the IoBridge would see +5VDC, if the power was out, then the IoBridge would see 0VDC.

Great solution - but i can't get it to work.

Every time i connect the little circuit to my IoBridge, the IoBridge locks up and drops off the network. And yes, i have confirmed i'm pushing +5VDC (and no more) to the IoBridge.

Here is the circuit i am using:



Is this circuit correct? Why is my IoBridge locking up? Suggestions....

[nick]

What happens if you just hook the +5V from the iobridge to the digital in instead of the wall wart?

Is it possible that the power supply is unfiltered so that it goes low 60 times a second?  Putting a capacitor over it would filter that out.

As an aside, how do you expect the iobridge to work when your power is out?

[zedman]

I'll answer in order:

1) I have not tried just connecting the +5VDC rail of the IoBridge to the Digital IN of the IoBridge - i will try this tonight.

2) Not sure about the power supply (plug pack) being unfiltered. It is a "regulated" plug pack (so the label says). Would I just add a capacitor (electrolytic i presume) across +5VDC and Ground (the same as the resistor?)? if so, what spec cap?

3) I have the IoBridge powered via a UPS. The plug pack is on raw house power. Therefore if the house power is lost, the plug pack will die, but the IoBridge will continue to operate - to that end, the LAN is also on the UPS feed - so the IoBridge will continue to communicate with the IoBridge server during a power outage.