How to choose the right receiver
There are several key features that distinguish different types of radio receivers and whether they are suitable for different projects.
|Number of relays
|A relay is a switch that opens or closes a circuit. In transmission, when a valid transmission signal is picked up by the receiver, it triggers a relay to change from open to closed or from closed to open. This change in state in the circuit is what controls the action – a light turning on, a door unlocking, or a gate automatically opening. If a receiver is equipped with more than one relay, it can control more than one circuit.
|This refers to the number of different transmitters that the receiver has space to accommodate.
|Modulation is the process of encoding the message into the sine wave that is transmitted. Demodulation is the reverse: separating out the original message from the transmitted sine wave. Common methods are AM and ASK. As long as both the transmitter and receiver use the same type, the message will be successfully transmitted.
|The frequency of the transmitter must be the same as the frequency of the receiver. This ensures that the sine waves are being sent to and from the intended components. Most CDVI transmission solutions run at 433.92MHz.
|Encoding is the process of converting data into a binary signal. Some methods offer additional security benefits, such as KeeLoq® hopping code, which constantly changes the valid passcode to prevent interception.
|Transmitters and receivers require a power supply to function. This might be a wired power supply or a battery. It is important to ensure you have the right version of the product with a power requirement that matches the rest of your system.
|If your components are to be installed outdoors or exposed to the elements, you should look for IP ratings. These measure the product’s resistance to the ingress of solids and liquids that might affect performance. The highest possible IP rating is IP68.