Circuit arrangement for selective frequency analysis of the amplitudes of one or more signals
Circuit arrangement for generating tuning voltage
Receiver having a measurement instrument which is used as a tuning scale
Remote transmitter and housing
Visor and garage door operator assembly
Remote-controlled automatic control apparatus
Television/telephone system with annunciator and intercom feature
Rearview mirror transmitter assembly
Transmitter and receiver for controlling the coding in a transmitter and receiver
ApplicationNo. 688820 filed on 07/26/1996
US Classes:340/825.22, Program control340/5.25, Programming of coded record340/5.61, Wireless transceiver340/825.69Radio link
ExaminersPrimary: Holloway, III, Edwin C.
Attorney, Agent or Firm
Foreign Patent References
International ClassH04Q 007/00
AbstractA trainable transmitter for learning the characteristics of a received RF signal and for transmitting a coded RF signal having the learned characteristics to a receiver for remote activation of a device, such as a garage door opener. The trainable transmitter includes a tunable RF circuit and a controller coupled to the RF circuit for selectively tuning the RF circuit during a training sequence. To provide a user with an early indication that a valid RF signal is being received at the initiation of the training sequence, the control circuit quickly sweeps the frequency at which the RF circuit is tuned from the lowest frequency to the highest frequency of a frequency range in which the carrier frequency of a valid RF signal would fall. If a signal is not detected during this initial fast scanning procedure, the training sequence is terminated and the user is so informed.