telephone conferencing equipment - Electronic Circuits Projects Diagrams Free

orpheus · 7th February 2005, 09:55 AM

heyy,
i'm a final year electronics and communication student doing a project on party line system, telephone conferencing equipment.
i am looking for dtmf decoder circuits ...........i already have a circuit that uses a mt8870b(dtmf decoder) ic along with shift registers n compators.but i'm lookin for more smaller circuits for my designs.
also i'm lookin for circuits that do on hook - off hook detection for telephone instruments.

fredsm · 7th February 2005, 02:27 PM

How complicated? I have circuits that range from using 567's,
to using dedicated pass/reject discrete filters, and to complex
filtered A/D converters, and dedicated DTMF decoder IC's.
<als>

orpheus · 8th February 2005, 04:09 AM

dtmf decoder with a/d convrtr or dtmf dedicated ic's wud do.......

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7th February 2005, 09:55 AM	(permalink)
orpheus	telephone conferencing equipment heyy, i'm a final year electronics and communication student doing a project on party line system, telephone conferencing equipment. i am looking for dtmf decoder circuits ...........i already have a circuit that uses a mt8870b(dtmf decoder) ic along with shift registers n compators.but i'm lookin for more smaller circuits for my designs. also i'm lookin for circuits that do on hook - off hook detection for telephone instruments.

7th February 2005, 02:27 PM	(permalink)
fredsm	How complicated? I have circuits that range from using 567's, to using dedicated pass/reject discrete filters, and to complex filtered A/D converters, and dedicated DTMF decoder IC's. <als>

8th February 2005, 04:09 AM	(permalink)
orpheus	dtmf dtmf decoder with a/d convrtr or dtmf dedicated ic's wud do.......