Re: Electronic circuit designer


<eddiecarron@xxxxxxxxxxxxx> a écrit dans le message de news:
1182363452.806108.111160@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
I am a retired teachers looking at Voice Stress Analysis as a hbby. I
need a competent circuit designer, professional or amatuer to design
and build a fairly simple test board for me. Naturally, I will be
prepared to pay any reasonable price for this work. In the first
instance, please contact me with a price quote to produce a working
prototype board as follows.

The board would have a European female telephone input socket. The
telephone input signal would be divided into two streams.

1. One stream would be passed through to a short lead terminating in a
male European telephone plug which could be connected to a standard
telephone, so completing a normal telephone line.

2. The second stream would be directed through a lowpass filter with a
fairly sharp cut off frequency of 12 Hz. The dominant frequency
passing though the filter would be displayed on an LED array or bar
which would approximately show the dominant frequency in the 0 to 12
Hz range. The device should be powered by a 9V battery and appropriate
terminals for such a battery should be included.

I am advised that this is not a highly complex circuit for any
competent engineer and would appreciate anyone with the appropriate
skills, advising me of their charge for this service and also letting
me know somethings of their credentials, experience etc.

Eddie Carron

HI,
As others, I think you missed something : there isn't any signal in the DC
to 12Hz band on a phone line. May I suggest a first zero cost step : why not
connecting a PC sound card input to your phone line, may be just with a
microphone, and analyzing the sound with a standard PC-based spectrum
analyzer software ? Of even with more complex algorithms developped in
Mathlab, Scilab of similar ? Once you will be 100% sure of what you want to
extract from the audio then the hardware design will be easy.
Yours,
Robert
www.alciom.com


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Relevant Pages

  • Re: Electronic circuit designer
    ... need a competent circuit designer, ... One stream would be passed through to a short lead terminating in a ... which would approximately show the dominant frequency in the 0 to 12 ... The device should be powered by a 9V battery and appropriate ...
    (sci.electronics.design)
  • Electronic circuit designer
    ... need a competent circuit designer, ... One stream would be passed through to a short lead terminating in a ... which would approximately show the dominant frequency in the 0 to 12 ... The device should be powered by a 9V battery and appropriate ...
    (sci.electronics.design)
  • Re: Electronic circuit designer
    ... need a competent circuit designer, ... One stream would be passed through to a short lead terminating in a ... which would approximately show the dominant frequency in the 0 to 12 ... The device should be powered by a 9V battery and appropriate ...
    (sci.electronics.design)
  • Re: Electronic circuit designer
    ... need a competent circuit designer, ... One stream would be passed through to a short lead terminating in a ... which would approximately show the dominant frequency in the 0 to 12 ... I am advised that this is not a highly complex circuit for any ...
    (sci.electronics.design)
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