Post by thread:[OT]: AGC circuit required for electret mic

Hi, Anyone have a circuit that will give more or less constant output using a electret mic as input, even if you are 1 metre or 5 metres from mic? Circuit must be low cost, low current would be good <1ma? and simple if possible? Thanks Gary -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Well... let's see.... a typical miniature electret mic draws between 0.5 and 1.5 ma. You're asking the balance of the circuit to draw less than 0 ma right? The dynamic range to provide a constant output at your two limits will probably exceed 50db. I hope you're not thinking of running this on 5 volts are you? The control voltage/current of the circuitry to adjust gain of your compressor, the shunting or "compressing" of the audio alone will exceed a few ma. Are you sure of your requirements at this point? Rick "Gary (REMOVE THIS)" wrote: > Hi, > > Anyone have a circuit that will give more or less constant output using a electret mic as input, even if you are 1 metre or 5 metres from mic? Circuit must be low cost, low current would be good <1ma? and simple if possible? > > Thanks Gary > > -- > http://www.piclist.com hint: PICList Posts must start with ONE topic: > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

At 03:02 PM 4/27/02 +0100, Gary (REMOVE THIS) wrote: >Hi, > >Anyone have a circuit that will give more or less constant output using a >electret mic as input, even if you are 1 metre or 5 metres from mic? >Circuit must be low cost, low current would be good <1ma? and simple if >possible? > >Thanks Gary What is the intended application? Do you need to preserve the envelope of a speech or music signal or is the signal a tone of some sort? What output signal level do you need from the circuit? The problem is that there are MANY techniques available to you: ranging very cheap limiters (clipping circuit) on through very complex (maximize modulation level for a broadcast transmitter). You need to specify what you need. dwayne Dwayne Reid <spam_OUTdwaynerTakeThisOuTplanet.eon.net> Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 18 years of Engineering Innovation (1984 - 2002) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

David Covick a icrit : > > Gary, > > I've sent you a schematic off list of what I use for my ChipCorder > (ISD4002). > This works very well, not know what exactly you are looking for. > Could you please send me a copy of your schematic ? Thank you. Gaston -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

I would be interested in a copy of this schematic as well. Would you please send me one, too? -----Original Message----- From: David Covick [.....dacKILLspam@spam@WEST.NET] Sent: Saturday, April 27, 2002 3:47 PM To: PICLISTKILLspamMITVMA.MIT.EDU Subject: Re: [OT]: AGC circuit required for electret mic Gary, I've sent you a schematic off list of what I use for my ChipCorder (ISD4002). This works very well, not know what exactly you are looking for. David ----- Original Message ----- From: "Gary (REMOVE THIS)" <.....questuk1KILLspam.....HOTMAIL.COM> To: <EraseMEPICLISTspam_OUTTakeThisOuTMITVMA.MIT.EDU> Sent: Saturday, April 27, 2002 7:02 AM Subject: [OT]: AGC circuit required for electret mic Hi, Anyone have a circuit that will give more or less constant output using a electret mic as input, even if you are 1 metre or 5 metres from mic? Circuit must be low cost, low current would be good <1ma? and simple if possible? Thanks Gary -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listservspam_OUTmitvma.mit.edu with SET PICList DIGEST in the body