Page 1 of 2 12 LastLast
Results 1 to 10 of 17

Thread: audio signal to ground or power signal

  1. #1
    Maximum Bitrate sporty_drew's Avatar
    Join Date
    Mar 2006
    Location
    Iowa
    Posts
    662

    audio signal to ground or power signal

    I was wondering if there is any way to take a signal coming from rca wires and change it into a power or ground singnal that you would run into a relay, then off of that relay you could send a signal to the mute wire on your headunit. That way you could hook up an scanner and each time a transmission would come thru it would be heard over your speakers. Thanks, Drew
    1998 Camaro Worklog Starting over, New setup for 2010

  2. #2
    Fusion Brain Creator 2k1Toaster's Avatar
    Join Date
    Mar 2006
    Location
    Colorado, but Canadian!
    Posts
    10,045
    I thought of a way to do this a while ago... I'll see if I can find the post. Had to do with using a 4 diodes in a diamond configuration (to take AC to DC) and then sending it through a few capacitors to smooth it out, then through a transistor to make it 12v for regular relays as well as a big inductor just to store more charge. That should produce a somewhat level signal but it has never been tested.
    Fusion Brain Version 6 Released!
    1.9in x 2.9in -- 47mm x 73mm
    30 Digital Outputs -- Directly drive a relay
    15 Analogue Inputs -- Read sensors like temperature, light, distance, acceleration, and more
    Buy now in the MP3Car.com Store

  3. #3
    Maximum Bitrate sporty_drew's Avatar
    Join Date
    Mar 2006
    Location
    Iowa
    Posts
    662
    i would love to see a diagram of this or at least a parts list. I'm will to try anything i the chance that it'll work. Thanks
    1998 Camaro Worklog Starting over, New setup for 2010

  4. #4
    Newbie
    Join Date
    Jul 2005
    Posts
    44
    What 2k1Toaster said is a rectifier -> envelop detector -> amplifier - the problem with the design is that a transistor is an inverting amplifier - so you would end up turning the relay off when you had signal instead of on. You can fix this by adding a second transistor. Of course you only need one transistor if you're making a ground instead of a power wire - but u could have some strange side effects.

    You should be able to form your own circuit diagram by searching for the individual components in google. Search for Common Emitter instead of amplifier.

    Spuzzdawg

  5. #5
    FLAC
    Join Date
    Oct 2006
    Location
    Las Vegas
    Posts
    1,286
    common collectors dont invert inversion is not a function of the transistor, it's a function of the resultant 'voltage divider'.
    It's been a while...

  6. #6
    Constant Bitrate henkbliek's Avatar
    Join Date
    Dec 2002
    Location
    Netherlands
    Posts
    172
    Assuming the MUTE input is a rather high-impedance input, it might suffice if you just take the peakdetector (diode+capacitor) between the speaker output and the mute input. Would save you all the transistor hassle.

    BTW inversion is a function of amplifier configuration.

    white bream
    working on a trilogy: CARGO - UNIGO - MERGO
    CARGO = the Car Computer
    Intel Celeron M, [P]SDC, uBlox GPS, GPRS, WLAN, Silabs FM, RDS, TMC,
    Dual-audio, Onecable TFT, Microsize: 45 x 108 x 168mm (1.8 x 4.3 x 6.6")

  7. #7
    Newbie
    Join Date
    Jul 2005
    Posts
    44
    common collectors also have a voltage gain close to one therefore negating the reason for using a transistor

  8. #8
    Maximum Bitrate sporty_drew's Avatar
    Join Date
    Mar 2006
    Location
    Iowa
    Posts
    662
    wow i seem to be getting more confused with each reply...
    1998 Camaro Worklog Starting over, New setup for 2010

  9. #9
    Fusion Brain Creator 2k1Toaster's Avatar
    Join Date
    Mar 2006
    Location
    Colorado, but Canadian!
    Posts
    10,045
    Quote Originally Posted by spuzzdawg View Post
    What 2k1Toaster said is a rectifier -> envelop detector -> amplifier


    Just do that. I have no idea what the others are babbling about. There are 2 types of transistors, one "inverts" and one does not. The only reason I suggested one is to take whatever weak signal is coming out of the circuit and amplifying to 12v so you can trip your amps turn on. Think of it as a really small relay. You could in theory use a relay, but the problem is there are not many relays that could be driven off the weird weak signal that is going to be put out because there wont be enough to physically create a huge magnetic field and move metal contacts. There is enough however to work some magic in some silicon.

    What the rectifier does:



    Common way of drawing in a circuit:
    Fusion Brain Version 6 Released!
    1.9in x 2.9in -- 47mm x 73mm
    30 Digital Outputs -- Directly drive a relay
    15 Analogue Inputs -- Read sensors like temperature, light, distance, acceleration, and more
    Buy now in the MP3Car.com Store

  10. #10
    Car Audio Moderator durwood's Avatar
    Join Date
    Sep 2006
    Location
    Chicagoland (St. Charles,IL)
    Posts
    2,028
    The MUTE signal wire on a headunit will mute the headunit when the wire sees a ground, not 12V. At least that is how it usually works. The MUTE wire is usually used to mute the audio so you can hear an incoming phone call and that is how it works with handsfree phone car kits. .

Page 1 of 2 12 LastLast

Similar Threads

  1. OEM Navigation Connectors
    By Mr Castulucci in forum General Hardware Discussion
    Replies: 15
    Last Post: 07-20-2010, 05:25 PM
  2. Converting an Audio Signal to a Voltage
    By ukchris in forum Car Audio
    Replies: 21
    Last Post: 08-19-2008, 06:32 PM
  3. FAQ: Power Supplies Explained (Part 1)
    By Bugbyte in forum The FAQ Emporium
    Replies: 14
    Last Post: 06-10-2007, 07:45 AM
  4. How exactly do you ground the audio wire?
    By SuperAJ in forum General Hardware Discussion
    Replies: 7
    Last Post: 01-03-2003, 08:46 PM
  5. power good signal - help me please!
    By BluCivic93 in forum General Hardware Discussion
    Replies: 2
    Last Post: 08-10-2000, 10:16 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •