Circtuit to mute audio on one src when src2 has audio pr

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tel0p
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Circtuit to mute audio on one src when src2 has audio pr

Post by tel0p » Wed Feb 26, 2003 12:37 am

I'm trying to figure out how to build a circuit, It will 'splice' the audio from my cell phone's 'ear bud' audio into my walkman's left (or both?) ear audio. I will hang the mic seperately. <p>What I would *like* is that if audio is present from the cell phone (ie, I'm on or getting a call) that the audio from the headphones is faded completely down. When the call ends (or the voltage in from the audio out = 0) the music volume would return to normal.
I'm sure this can be done just haning trouble finding the circuit diagram. Any takers? TIA!!
:)

russlk
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Re: Circtuit to mute audio on one src when src2 has audio pr

Post by russlk » Wed Feb 26, 2003 10:36 am

I posted a schematic at the URL below. I have not built it, so no guarentee. If you build it and have a problem, feel free to email me.
http://www.geocities.com/russlk/sigsw.jpg<p>NOTE: you have to copy and paste the URL because geocities does not allow links.<p>[ February 26, 2003: Message edited by: Russ Kincaid ]</p>

tel0p
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Re: Circtuit to mute audio on one src when src2 has audio pr

Post by tel0p » Wed Feb 26, 2003 2:36 pm

Thanks Russ! I will give it a shot and reply results! Anything I should know component wise? TA!

chessman
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Re: Circtuit to mute audio on one src when src2 has audio pr

Post by chessman » Wed Feb 26, 2003 2:58 pm

Does your cell phone's ring sound over the earphone? Both my phones don't do that, just something to think about.

tel0p
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Re: Circtuit to mute audio on one src when src2 has audio pr

Post by tel0p » Thu Feb 27, 2003 11:15 am

My phone doesnt ring in the earpeace per se. It does however make a slight click and then a hollowish, faint white noise sound even before the phone rings itself. I have yet to test the levels on it. What are the thresholds of this circuit?<p>Also, could someone point me to a good place for the DG419? It seems DigiKey only has them in 100pc where they have the TLC372 in singles.<p>I'm also curious if there is a variant of the DG419 to emulate DPDT? I would like to mute both (LR) channels of my headphones yet only have the one ear (L) come on for a phone call. I presume I could just include a second DG419 in the circuit Russ provided(?).<p>[ February 27, 2003: Message edited by: Costa ]</p>

russlk
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Re: Circtuit to mute audio on one src when src2 has audio pr

Post by russlk » Thu Feb 27, 2003 1:54 pm

I had an early Panasonic phone that used the earphone as the ringer. I can't hear that frequency any more!<p>I will look into using a quad switch instead of the DG419.
You ask about sensitivity; it is too sensitive, I need to put some hysterises in the comparator. About 100 mV should do it.<p>[ February 27, 2003: Message edited by: Russ Kincaid ]</p>

russlk
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Re: Circtuit to mute audio on one src when src2 has audio pr

Post by russlk » Thu Feb 27, 2003 8:55 pm

I have posted a new schematic using a quad switch, and have corrected some errors in the original schematic. I did not use hysteresis, I used a 100 mV offset instead.<p>Don't forget: you have to copy and paste the URL.
http://www.geocities.com/russlk/sigsw.jpg<p>Oops! I had the switch backward, the correct schematic is now posted.<p>[ February 28, 2003: Message edited by: Russ Kincaid ]</p>

tel0p
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Re: Circtuit to mute audio on one src when src2 has audio pr

Post by tel0p » Fri Feb 28, 2003 12:03 pm

Thanks Russ!

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