detecting whether a receiver is on

[hgupta1]

I have a receiver in my basement that I use for outside speakers. A few times its been accidentally left on, annoying all the neighbors. The receiver has 110V swtiched power outlet on it., and it isn't far from my Elk M1 or a computer with Homeseer on it. Whats thes best way to send a signal to the ELK M1 (which could then send me reminders?)

Thanks in advance!

 

[mustangcoupe]

I have a receiver in my basement that I use for outside speakers. A few times its been accidentally left on, annoying all the neighbors. The receiver has 110V swtiched power outlet on it., and it isn't far from my Elk M1 or a computer with Homeseer on it. Whats thes best way to send a signal to the ELK M1 (which could then send me reminders?)

Thanks in advance!

Either detecting the power LED is on or detecting the unit is consuming power by measuring current on the AC Line.

Here is one current monitor that is being used for a washer which could be used for a receiver instead

Here is one using LED status lights on a washer

 

[DavidL]

Or, just turn off the power to the receiver. Use UPB/ Zwave / Insteon etc that allows you to see the status of the outlet.

 

[rbroders]

Just connect a relay with a 110v AC coil to the switched outlet on the receiver and wire the contacts to an ELK input.

--Bob

 

[Sandpiper]

Just connect a relay with a 110v AC coil to the switched outlet on the receiver and wire the contacts to an ELK input.

--Bob

Or, plug in a wall-wart transformer into the switched outlet which drives a low voltage relay, with contacts wired to the M1.

 

[hgupta1]

Just connect a relay with a 110v AC coil to the switched outlet on the receiver and wire the contacts to an ELK input.

--Bob

Or, plug in a wall-wart transformer into the switched outlet which drives a low voltage relay, with contacts wired to the M1.

Thanks you all for so the help. I will definitely try the wall wart with a relay. This is such a wonderful board!

 

[Dave X10]

I use a TV trickle saver: http://www.smarthome.com/9782/TV-TrickleSa...gy-Saver/p.aspx

I plug a 12V AC wall-wart into the "extra" plug. Then I wire the wall-wart to a powerflash module. That gives me notice that the (TV in my case) is left on. But I also use macros with timers that auto turn off.. [and auto re-arm] to arm or turn off devices to prevent... forgetfullness.

 

[apostolakisl]

If you separated the two wires (hot and common) and wrapped one of them with a very fine guage thinly insulate wire, how many wraps you would have to make before the induced current would be enough to flip a small relay?

 

[gatchel]

If you separated the two wires (hot and common) and wrapped one of them with a very fine guage thinly insulate wire, how many wraps you would have to make before the induced current would be enough to flip a small relay?

I don't think this would be able to be done (practically) with the standby current of a receiver. I be interested to figure out the numbers though...

Any EE's want to tackle this one?

I think the best solution would be the wall wart with a relay. K.I.S.S.

 

[apostolakisl]

If you separated the two wires (hot and common) and wrapped one of them with a very fine guage thinly insulate wire, how many wraps you would have to make before the induced current would be enough to flip a small relay?

I don't think this would be able to be done (practically) with the standby current of a receiver. I be interested to figure out the numbers though...

Any EE's want to tackle this one?

I think the best solution would be the wall wart with a relay. K.I.S.S.

I was thinking that the relay would only close when the unit was on. So maybe 100 watts or something like that could induce enough current to throw the relay but 1 or 2 watts in standby would leave the relay open.

 

[apostolakisl]

If you separated the two wires (hot and common) and wrapped one of them with a very fine guage thinly insulate wire, how many wraps you would have to make before the induced current would be enough to flip a small relay?

I don't think this would be able to be done (practically) with the standby current of a receiver. I be interested to figure out the numbers though...

Any EE's want to tackle this one?

I think the best solution would be the wall wart with a relay. K.I.S.S.

I was thinking that the relay would only close when the unit was on. So maybe 100 watts or something like that could induce enough current to throw the relay but 1 or 2 watts in standby would leave the relay open.

I just had a simpler idea. What if you split the hot/common wires on the power cord (or did this to a cheapo extension cord) and wrapped one of them around a metal rod. Then put a standard magentic alarm contactor at the end of the rod. When power runs through the wire, a magentic field will develop on the metal rod and close the circuit on the alarm contactor which could be hooked into your Elk allowing you to monitor the on/off status of the device.

 

[jwilson56]

Why are you guys trying to reinvent the wheel? There are two ways to do this reliably. One get a small wall wart and relay and plug it into the switched AC outlet if it has one. No need to deal with 120 volts AC. Just use 12 volt wall wart and a 12 volt relay. You can get them cheap at places like http://www.allelectronics.com/ or http://www.goldmine-elec.com/

The second way is to use a current switch which can be bought off Ebay pretty cheap now and then. The ones I use have a built in relay and some even have a sensitivity adjustment on them. The last ones I bought were like $18 each and work very well. instead of cutting into the power cords I use a cheap three foot extension cord and use one wire from that to wrap around the current sensor.

Most of these current sensors use a HALL effect device to detect a very small magnetic field. Trying to wrap wire around a metal rod to detect it yourself will not be easy and will probably require many turns which will create an inductance which might have an effect on the internal powersupply of the receiver. Not even taking safety in considerations I would just do it with the proper device.


For my Now Playing setup I actually use some of both as not all my receivers have a switched AC outlet. These are all going into a Ocelot SECU-16 module either as a switched contact or a low voltage from the wall warts.

See my blog or showcase thread for more details.

 

[apostolakisl]

Why are you guys trying to reinvent the wheel? There are two ways to do this reliably. One get a small wall wart and relay and plug it into the switched AC outlet if it has one. No need to deal with 120 volts AC. Just use 12 volt wall wart and a 12 volt relay. You can get them cheap at places like http://www.allelectronics.com/ or http://www.goldmine-elec.com/

The second way is to use a current switch which can be bought off Ebay pretty cheap now and then. The ones I use have a built in relay and some even have a sensitivity adjustment on them. The last ones I bought were like $18 each and work very well. instead of cutting into the power cords I use a cheap three foot extension cord and use one wire from that to wrap around the current sensor.

Most of these current sensors use a HALL effect device to detect a very small magnetic field. Trying to wrap wire around a metal rod to detect it yourself will not be easy and will probably require many turns which will create an inductance which might have an effect on the internal powersupply of the receiver. Not even taking safety in considerations I would just do it with the proper device.


For my Now Playing setup I actually use some of both as not all my receivers have a switched AC outlet. These are all going into a Ocelot SECU-16 module either as a switched contact or a low voltage from the wall warts.

See my blog or showcase thread for more details.

You don't need to cut into the wire. Just seperate the two sides from each other leaving the insulation intact. If you wrapped both the hot and common the two magnetic fields would cancel each other out.

The problem with using a switched AC outlet is that the you have to shut the thing down completely, not just put it in standby. Some things don't do well when you switch them externally instead of putting them in standby. Also, you will no longer be able to turn the item on/off using its built in system (IR remote most likely) but instead have to use a separate control that runs the switched AC unit.

I think I am going to try this tonight using a cheapo lamp wire type extension cord. The magnetic field needed to throw an alarm contactor is pretty small so I bet I don't need too many wraps. I made an eletro-magnet in 1st grade once with a nail, about 10 wraps of wire, and a 9 volt battery that could pick up nuts and bolts, so I bet 10 wraps on an old bolt would do the trick when running 110v. I'll let you know how it goes.

 

[jwilson56]

You don't need to cut into the wire. Just seperate the two sides from each other leaving the insulation intact. If you wrapped both the hot and common the two magnetic fields would cancel each other out.

The problem with using a switched AC outlet is that the you have to shut the thing down completely, not just put it in standby. Some things don't do well when you switch them externally instead of putting them in standby. Also, you will no longer be able to turn the item on/off using its built in system (IR remote most likely) but instead have to use a separate control that runs the switched AC unit.

I think I am going to try this tonight using a cheapo lamp wire type extension cord. The magnetic field needed to throw an alarm contactor is pretty small so I bet I don't need too many wraps. I made an eletro-magnet in 1st grade once with a nail, about 10 wraps of wire, and a 9 volt battery that could pick up nuts and bolts, so I bet 10 wraps on an old bolt would do the trick when running 110v. I'll let you know how it goes.

Well to start with I have a electronics degree so I think I understand the basics here. Not sure you really understood what I typed.

First off using a current sensor....unless you have a split core type current sensor you will have to not only separate the hot and common wires but also cut one to wrap it around the sensors core. Using a cheap short extension cord will allow you to get at the wire without needing to cut into the cord that comes with the receiver which often is attached to the unit.

As for a using the Switched AC outlet on the back of the receiver I have no idea what your talking about. You obviously missed my point entirely. On many receivers there is an AC outlet on the back that is hot when the receiver is on and off when in standby. You simply plug in a wall wart into this outlet which then will put out 12 volts when the receiver is on. You can then use this to energize a small relay to give you a set of contacts that will be closed when the receiver is on. I made no reference to switching the receiver on and off with a relay.

 

[apostolakisl]

You don't need to cut into the wire. Just seperate the two sides from each other leaving the insulation intact. If you wrapped both the hot and common the two magnetic fields would cancel each other out.

The problem with using a switched AC outlet is that the you have to shut the thing down completely, not just put it in standby. Some things don't do well when you switch them externally instead of putting them in standby. Also, you will no longer be able to turn the item on/off using its built in system (IR remote most likely) but instead have to use a separate control that runs the switched AC unit.

I think I am going to try this tonight using a cheapo lamp wire type extension cord. The magnetic field needed to throw an alarm contactor is pretty small so I bet I don't need too many wraps. I made an eletro-magnet in 1st grade once with a nail, about 10 wraps of wire, and a 9 volt battery that could pick up nuts and bolts, so I bet 10 wraps on an old bolt would do the trick when running 110v. I'll let you know how it goes.

Well to start with I have a electronics degree so I think I understand the basics here. Not sure you really understood what I typed.

First off using a current sensor....unless you have a split core type current sensor you will have to not only separate the hot and common wires but also cut one to wrap it around the sensors core. Using a cheap short extension cord will allow you to get at the wire without needing to cut into the cord that comes with the receiver which often is attached to the unit.

As for a using the Switched AC outlet on the back of the receiver I have no idea what your talking about. You obviously missed my point entirely. On many receivers there is an AC outlet on the back that is hot when the receiver is on and off when in standby. You simply plug in a wall wart into this outlet which then will put out 12 volts when the receiver is on. You can then use this to energize a small relay to give you a set of contacts that will be closed when the receiver is on. I made no reference to switching the receiver on and off with a relay.

OK, the switched outlet that many receivers have on the back. I thought you meant buying a switched wall outlet to turn the whole reciever on and off. I was thinking in more general terms, not so specific to a receiver but any electronic device.

Anyhow, just for fun I went into my workshop, took a 6 foot cheapo extension cord and split it (didn't expose any wire), wrapped bout 4 feet of it around a bolt, plugged my circular saw into it (it was handy) and turned it on. The magnet was quite strong, pulling nuts about a half inch. I didn't have time to dig out my stash of left over alarm contacts, but I am feeling confident that it would be plenty of magnet to close the contact. The circular saw pulls about 13 amps so it might not work with a weaker draw. But the theory works and more or less wraps of wire is all it would take to work with more or less current draw. The nice thing with this is that it is dirt cheap (maybe $5 for an extension cord and alarm contact, free if you are like me and have extras just sitting around), and would work on anything that draws a reasonable current (not just receivers with the switched outlet on the back). A good question is whether there would be any noise induced in the current that might adversely affect some sensitive items, but I kind of doubt it.