US Patent 7154410 Multifrequency garage door opener

A garage door power module is provided with the capability of operating over a number of different operating frequencies by configuring a power module chassis with a receptacle for receiving radio receivers where each of the receivers is adapted to receive one of the frequencies. The receptacle located near one edge of the chassis and is configured with a planar surface and support members that permit the receivers to be slidably inserted and removed from the receptacle. In addition the radio receiver is equipped with a plug connector and the receptacle is equipped with a socket for receiving the plug connector in order to transmit radio control signals from the receiver to logic control circuits in the power module.