how to measure the on/off status of my video source selector?

[DeLicious]

So, I recently bought a used AMX PCS2 power current sensor to detect the on/off status of my television and video source selector (or video switch, if you like). It worked fine for the TV, but I couldn't (and still can't) get it to work with the video switch.

so, i took out my trusty kill-a-watt and plugged the video switch into it. it turns out both the on and off (actually standbye) states use the same amount of power. i don't know which should be different, but amps, volts, and watts were all the same in both states, which explains why the power current sensor doesn't know the difference between on and off.

i then remembered i had seen a "how to" article to monitor the status of something using a status light and a photoresistor, but that only works with digital inputs, and all i have available to me is contact closures.

can anybody think of a way for me to monitor the status of this appliance that results in a contact closure, and doesn't rely on how much power it draws? is there a way to rig a photoresistor-type solution to result in a contact closure?

thanks in advance
Adam

 

[DeLicious]

oh, as a note, i will also be getting some video sync sensors, so that will tell me which output of the switch is selected, but i don't know if it will tell me power status. i don' t think i should have to check the values of 4 different video sync sensors to determine a single power status of a device.

 

[zpollock]

Does the switcher pass the video signal through when it's off? If not, then you may be able to use the presence of the sync signal to monitor the power status. As you pointed out though, you'd need to know which input to look at, or have logic to select that input before you check it.

Also, a contact closure is basically a digital input. It's on or off (as opposed to analog which may have a wide range of values), so with the proper interface a photoresistor detection circuit should still be an option if there's a status LED that will trip it.

Are you controlling the device via IR (I'm assuming it's not serial)? If so, are there discreet on and off codes available? You may not need to know the status, as long as you have a way to guarantee that it's in the state you want it to be. Unique on and off codes will allow you to do that.

 

[DeLicious]

The lack of discrete on/off codes is the crux of the whole problem my harmony remote just sends a power toggle to the video switch, and sometimes it receives it and sometimes it doesn't.

i may end up just going with the video sync sensor solution, although it's not my first choice.

i did pry open the video switch last night to see if there were any LED's i could get access to and use global cache's AC/DC power sensor, but everything was glued together, and I didn't want to mess with that.

thanks for the input, Zac.

 

[SteveQ]

Why do you want to know if the video switching box is ON? Why not just turn it OFF with an x10 appliance module when the TV is OFF?

Steve Q

 

[DeLicious]

hadn't thought of that either... seems a little extreme, no? in any case, even when the appliance module is on, the switch could still be in standby mode.

 

[Waynedb]

so, i took out my trusty kill-a-watt and plugged the video switch into it. it turns out both the on and off (actually standbye) states use the same amount of power. i don't know which should be different, but amps, volts, and watts were all the same in both states, which explains why the power current sensor doesn't know the difference between on and off.


thanks in advance
Adam

Why bother even turning it off? If the power draw is the same on or off, wouldn't it be easier to just leave it on all the time?

 

[DeLicious]

also not a terrible idea. how come i don't think of this crap?

 

[SteveQ]

[/quote] Wayne,
Why bother even turning it off? If the power draw is the same on or off, wouldn't it be easier to just leave it on all the time?
[/quote]


If you use an appliance module (or a power strip) to turn it OFF, the power consumption will be zero! Thats the whole point of turning it OFF.

My cable box draws 47 watts when OFF (its called standby...there is no OFF) and 50 watts when ON. I use it about 4-6 hours per day. So I use an appliance module to turn it on at 6 PM and OFF at midnight.

Steve Q

 

[Waynedb]

If you use an appliance module (or a power strip) to turn it OFF, the power consumption will be zero! Thats the whole point of turning it OFF.

My cable box draws 47 watts when OFF (its called standby...there is no OFF) and 50 watts when ON. I use it about 4-6 hours per day. So I use an appliance module to turn it on at 6 PM and OFF at midnight.

Steve Q

I don't know what the power draw of this particular video source selector switch is but I would imagine it is much lower than your cable box, if I had to guess I would think that it draws 10 watts or less.

 

[DeLicious]

I don't remember what the number was.... in any case, I don't have a problem with leaving it on.