IR timer

I need to send an IR command to a box and then that box would close a relay after a period of time. Basically I have a projector lift and I need to turn off everything in the room and leave the lift down for the projector to cool off. After about 10 minutes the projector has cooled off and the projector can go up. I would like to be able to leave the room. Unfortunately I haven't found a way to get the projector to trigger the on and off. I use IR for all of my controls but I have an HAI panel near by so that is an option only if I can send a command via the iRule program I use to control the room with my iPad. The projector lift only has a toggle there is no up or down discrete command.... Also the lift isn't aware of it's state although there is some switches for turning the power on and off to the projector.

I was thinking of using a IR relay (Xantech CC12) and then using an elk timed relay to actually toggle the lift. The only problem with this configuration is I think it could get pretty pricey...

Any thoughts would be appreciated.

Thanks!

Neil

Do you have any info on the lift so we can look it up?

My first thought honestly is an adjustable current switch - generally during cooldown the fan is still running - once the fan stops, the consumed current should drop. As for knowing if the thing is up or down, if the built in switches won't do it, it should be easy enough to add a surface mount contact switch inside the lift (not visible) to detect its state.

Does the device have any other way to trigger up/down besides just IR? Are there inputs for a wired button?

Could you use temperature sensor to sense the projector temperature? you could feed the temperature sensor to a WebControl board. When it sensed the temperature below certain degree, it sends control to relay board to drive up the lift. You need to add a stop switch feed to the TTL input of WebControl to stop the motor. The total cost is probably below $50.

I could put a temp sensor from HAI on the lift and when it gets below a certain temperature I can turn it off. The only problem is I need to know if it is down as well. Not an ideal situation.

Current sensor probably wouldn't work only because I am not taking the projector apart and the current draw will be all over the place...

Can you give us any info on the lift? You mentioned that there's some switches for turning the projector on/off - if they do it based on the position of the projector, you can use that very cheaply to know the position of the lift - or as I mentioned earlier, with a simple surface-mount contact sensor as well.

I wasn't recommending taking anything apart - there's ways to sense current either via a power strip or through a CT over the slightly modified power cord. It doesn't matter how much voltage varies as long as there's a minimum that can be sensed - I have that power strip and you can adjust that limit pretty well.

Or - many projectors will have a video out (for looping video) or some other way to detect when it's putting out a picture... you can always set it so that after the display stops showing video, a 5-minute timer starts after which it'll close it.

There's lots of options here - most of which you can pull off for under $50...

heffneil said:

I could put a temp sensor from HAI on the lift and when it gets below a certain temperature I can turn it off. The only problem is I need to know if it is down as well. Not an ideal situation.

Click to expand...

Can you install a position sensor, like a roller switch to detect if the lift is up?

Here is the page on the lift:

http://www.chiefmfg.com/Series/SL151

Like I said there are some switches but I think they run AC current through them so that if the unit is up the power to the onboard receptacle is off.

I wish the darn projector would tell me when its ok to turn the power off but I asked on AVSForum and no one knows of a trigger for that. I could do temp sensor and a position sensor and have the HAI system lower it but the problem really becomes that I want to turn it off and then raise. I have an ocelot I never used also laying around I never used in the spare parts box....

Anyway let mek now if you guys have some good ideas. I looked at elk's timer but it doesn't time longer than 60 seconds so that part won't work....

Thanks,

Neil

Well looking at that manual, you can do anything you want... they gave you contacts that'll tell you when it's up or when it's down, and gave you very simple triggers for separate open/close that you could easily run through anything - the HAI or any other control board that can do trigger a basic relay. There's even sensors that could alert your HAI upon an obstruction that were to block it from opening/closing. Your IR control doesn't have discrete open/close, but the lift gives you several options.

To me it seems like the only remaining obstacle is knowing when the projector is done cooling off. For a very simple method, you could use that power strip I linked above - plug the projector into the control, plug a little 12V wall wart into one of the switched outlets - and set the current sense precisely so that when the projector powers down to nothing but real standby, it cuts off the other outlets which in turn cuts off the wall wart, closing the relay that's connected to an HAI zone - telling the HAI that the projector has gone into true standby... at which time the HAI triggers the close by simply operating a relay to short terminals 12 and 13 for a moment.

If you need help understanding more of the electrical concepts behind using those terminals let us know and we can help out... you can use the HAI or anything standalone that can handle even the most basic inputs/outputs. This could even be programmed into a single UPB input/output module I'd bet.

i see the terminals showing the condition of the lift but I still don't know how I want to know WHEN to put the lift up? A timer is just fine really?

There are a couple of ways to know if the projector is ready to come up.

1. Temperature sensor attached to the projector
2. Using something that'll sense video out - and when video turns off, start a timer of some sort.
3. My personal favorite, via voltage sensing.

There's a few ways to avoid voltage sensing. One is to modify the power cord slightly or an extension cord so that the hot wire is separated to where you can slip a Current Transformer over the top, then use something that can read analog voltages to detect different states - like cooldown, full on, or asleep. Or, get a voltage sensing relay/switch - you may have to wind the hot around the CT a couple times to boost voltage when in just fan mode, or get an adjustable one that you can fine-tune. These are nice because they can hook to a zone and be either secure or not secure. Or last is similar enough, but using something like that power strip listed above, you fine tune the current sensing shutoff point - your projector is what it's sensing, and you use a 12V wall wart as I described above. That wall-wart powers a generic automotive relay which is connected to something like an HAI zone. When the wall wart is getting power, it is secure, when it loses power, the zone become not-secure.



What I like about hooking something into the voltage sensing of the projector is that you basically never have to operate the lift again - it can be set so that if the projector is consuming any notable current, it automatically sets the lift down... once all current ceases it goes back up - completely automatically.

Is that making sense yet?

Yes makes sense but doesn't work because when the projector lift is up the projector can not turn on - the power is switched. I guess I could disable this safety but the idea is not to move the projector with it on or when it is up in the ceiling?

Temperature could of course be thrown off and not really work properly. Current sensing is a better idea but one other thing is there a sensor to detect color of an LED? Reason I ask is that the status light is GREEN when on, Yellow when cooling and then Red when Off / Standby.

Thanks!

Neil

You know what I was just thinking: I can use the HAI panel to know what the state of the projector and if it is down at 3 am I will raise it? I don't expect to be using it at 3 am.

Thanks,

Neil

:wacko:

You don't like that idea?