Consumer Electronics

REMOTE CONTROL TRANSMITTER

The SAA–5000A is a MOS N-channel IC which provides the encoding and modulation function for the remote control of television receivers, including those equipped with Teletext and Viewdata facilities. The internal block diagram of IC–SAA 5000A is shown in Fig. 35.6. The transmitter using SAA–5000A is based on the time ratio discrimination encoding system. It provides 32 commands which are activated by switch controls on the keyboard matrix. The IC is connected to this keyboard by six matrix outputs and six matrix inputs.

It utilises the TRD method of word encoding. It trasmits a 24 bit code for every transmitted command. It consists of a 7 bit “Start-Code” followed by a 5 bit “Message”. At the end of the message code, ...