A few years ago i replaced the entryphone panel lighting at the entrance to my flat with LED lights to avoid having to replace the 12V incandescent filament bulbs every 6 months or so. The LED lighting has been working faultlessly for the past 4 years. Click here for more details. While i was installing the LED lighting a neighbour asked me if i could install the same in their entryphone panel which i did and if i had ever considered installing a CCTV or video camera at the front door. She told me she had investigated this but she had received quotes in excess of GBP2500 to wire up her and her 8 neighbours flats with the equipment. They had rejected the idea. I started thinking about this and came up with the system below using a few parts i had to purchase and some i had to hand. The plan was to use low cost readily available CCTV cameras and this transmitter to transmit the signal to receivers in each flat . Each resident could decide whether or not to purchase a receiver and use the video door entry system.
Here the front panel of the transmitter can be seen.
The system accepts audio and video inputs using standard RCA phono type plugs.
The aerial is an SLA screw on type which can be folded down for storage.
Here the rear of the unit can be seen. There is a 12V power socket and a miniature on/off rocker switch.
Holes were drilled in the top of the case to allow some air flow over the transmitter module. Holes were drilled in the same location on the bottom of the case.
With the case top removed the relatively simple internals can be seen. The 2.4GHz transmitter module is clearly visible on the left. The on/off switch is at the bottom right and the power connector is at the top right.
The terminal block in the centre of the case wires all the components to the the power. A diode was inserted into the power line to ensure that the system would not be damaged by connecting a power supply of the wrong polarity.
This picture shows the transmitter beside a commercially available 2.4GHz receiver.
The vertical round structure on the right is the receiving aerial which can be rotated and tilted to the best angle. It folds flat onto the top of the unit for storage.
The rear of the unit has RCA phono connectors to connect to a display unit and audio. There is also a socket for DC power and a switch to set the receiving channel to match the one set on the transmitter.