This is more home automation, but I need help!

[ssnapier 0]

Actually, this is not a "home" question at all but anyway let me explain. I have 8 streetlight poles with a wireless bridge and 3 cameras on each pole. These are two Mobotix cameras and a Panasonic PTZ (all IP). I know I can send an RS-232 signal from the Mobotix cameras to whatever I want, but it is just something I have not personally done before. My problem is that the lights and cameras are all on a common power source and I need to make sure the cameras and wireless gear stay on evn if the lights are turned off. Is there a cheap and simple method (relay?) that will allow me to shut off only the lights and leave the cameras on?

 

This is something I really should know how to do, but thanks to a few weird quirks I simply have never been exposed to it... your help would be greatly appreciated.

Edited June 21, 2012 by Guest

[ssnapier 0]

Ok, according to the Mobotix M-12 manual I have a 5VDC Line available on this DB-15.

 

Here is the pinout:

 

[ssnapier 0]

My brother has suggested this little box:

 

http://www.bb-elec.com/bb-elec/literature/documentation/datasheets/232drio_0812ds.pdf

[ssnapier 0]

Any input?

[dustmop 0]

Assuming you want to only control the lights by using the camera output, my thought is this:

 

If you know you can trigger the output on the camera in a way that you can control (webpage, DVR, etc), then all you need is a relay, like a 12VDC < 100mA coil relay (the contact rating needs to be greater than whatever your lights are, i.e. 110/277/whatever at whatever amp load you need)

 

It's an open collector output, and an open collector essentially acts a ground (by means of an NPN transistor). So you need your positive voltage (+12VDC) going to one leg of the relay, then the other leg going to pin 1 of the DB-15. When you trigger the output, it lets the voltage find a ground, and the relay will change states. If they are PoE cameras, and you have no local power, that rules out 12V relays, as the camera only has a 5V output. The problem here is that 5V relays are usually meant for PCB type installations, and not your classic (and super easy) socket type. Doesn't mean you can't make it work, however. But if you have local power, just find yourself a 12VDC power supply.

 

It looks like it can sink 24V on the open collector, but the issue to watch out for is difficulty finding relays with coils that can switch 24V <50mA, and still have large enough contacts for high voltage.

 

If you use double throw relays, they will have 2 distinct states, whereas a single throw is just on and off, like a normal light switch. I say this, because you could use DT style to make so if the camera were to up and die, then the lights could be forced into an on state by using the non-powered circuit of the contacts.

 

Then you just run the HOT leg of the mains power going to the light through the contact of the relay, and you should have a relay controlled light!

 

I actually do stuff like this quite a bit in the door access world, and have 2 relays on my desk that fits the bill for everything I do. I use DIN rail sockets to make installs look nice where applicable, or they screwed into the panels.

 

Omron MY4-12VDC 4PDT - 12vdc 75mA coil, contacts will do 3A @ 250VAC or 3A @ 30VDC

Allen-Bradley 700-HA32Z12 - 12vdc 100mA coil, contacts will do 30A @ 120VAC, 15A @ 240VAC, or 10A @ 30VDC

[hardwired 0]

You could drive the input of a solid state relay for the light control directly with the 5 volt output (pin 13) and the Out 1 line (pin 1). Depending on the load current, you might need a heat sink on it. Take a look at these for an example. http://www.crydom.com/en/products/catalog/s_1.pdf