1. Audio Controlled Relay. A switch designed to operate when the level of a sound signal crosses a predetermined threshold. Among other things, these relays are used in broadcast applications to detect "dead air" and trigger an alarm circuit.
One example:
ST-ACR1 Line-Level Audio Controlled Relay - 0.5 to 5 s
2. Wireless. Adjacent Channel Rejection is a measure of how strong the immediate higher or lower radio channel would need to be to cause a receiver to malfunction. Poor RF systems may have an ACR of 60 dB or less, while better ones may be on the order of 80 dB or more. The "next channel" must be defined by the manufacturer or by a regulator, and is not necessarily the next tuning step in a receiver (because the channel bandwidth is often greater than the tuning step).
One example:
ST-ACR1 Line-Level Audio Controlled Relay - 0.5 to 5 s
2. Wireless. Adjacent Channel Rejection is a measure of how strong the immediate higher or lower radio channel would need to be to cause a receiver to malfunction. Poor RF systems may have an ACR of 60 dB or less, while better ones may be on the order of 80 dB or more. The "next channel" must be defined by the manufacturer or by a regulator, and is not necessarily the next tuning step in a receiver (because the channel bandwidth is often greater than the tuning step).
