Electronic Circuits and Software Related Telephone Ringer using 556 dual timers The circuit requires four astable multivibrators for its working. Therefore two 556 ICs are used here. The IC 556 contains two timers (similar to 555 Telephone Ringer using 556 dual timers The circuit requires four astable multivibrators for its working. Therefore two 556 ICs are used here. The IC 556 contains two timers (similar to 555 Audio Visual Ringer Many a times one needs an ex- tra telephone ringer in an ad- joining room to know if there is an incoming call. For example, if the telephone is insta DTMF Decoder 2 by Infidigm The DTMF decoder 2 is a useful tool used for decoding DTMF (Dual Tone Multi frequency) generated by telephones. The decoded digits are viewed on a 16x Chip recorder customizes phone ringer The heart of the ringer is a chip-recorder ISD1110P IC, which can play as much as 10 seconds of telephone-quality recorded sound. A high-efficiency st
