can some one suggest an electrical circuit for...?

Question

we own a hotel and have decided to fix lcd televisions in the rooms.but we have heard of cases from other hotels that some customers cut off the wires and steal the lcd tv.as they are sleek they can be packed in their suitcases.can we design an electrical circuit which will warn us when the power cord is cut off.all the tvs will have their power from the control room.any ideas please?

Answer 1

Your Problem is that power will not always be applied to the TV (e.g when the set is turned off). So that rules out simple current sensing circuits.

Your best bet would be some kind of wire loop alarm where-by if the wire loop is broken then the alarm sounds.

If you added a simple 3.5mm jack socket to the rear of the set and short the terminals. Then on your loop cable simply connect a 3.5mm jack plug with the loop cable to your control room. This wire would have to be either unplugged or cut, sounding the alarm in your control room.

The actual alarm circuitry would be in the control room and a separate alarm could be provided for each room. Power would be supplied in the control room, where batteries are shown you would use a power supply.

I have found a few circuits that could easily be adapted for your project.

See links below.

Answer 2

How much money do you want to spend? The easy way would be to install an anti-theft gate (similar to the ones used in stores) and then put an RFID tag inside the TV. When someone tries to carry it out, it sets off the alarm. Such systems are comercially available and cost a few thousand dollars. HTH ☺ Doug

Answer 3

They make TVs just for Hotels.

But as for security, usually a wall mounted with a pull down feature.

The wall mount will be bolted to the back of the unit.

Cant fit a socket and ratchet/hand back there to unbolt it.

Swivel it down to unbolt it but having a lock built in or put a lock in a place where it will jam it tryed to be swiveled.