The SKY13292-365LF, a 4 x 2 switch matrix, combines a digital decoder with the RF switching network and tone/voltage detect within a lead-free, RoHS-compliant QFN plastic package measuring 4 mm x 4 mm ...
Decoding the telephone-generated DTMF is the purpose of building the DTMF decoder 2 which can be connected directly to a serial port and use a HyperTerminal on a PC to view the digits. A 16×2 LCD ...
Connect Systems Inc.'s FLEX-D Model 19 simplex repeater features up to 120 seconds of voice storage and two-tone validation. This controller stores the tones and voice in voice memory and rebroadcasts ...
One late night many decades ago, I chanced upon a technical description of the Touch-Tone system. The book I was reading had an explanation of how each key on a telephone sends a combination of two ...