Electronics Expert question?

[Dr]

Hi All: I am new to this forum but have always found the subject of over unity awesome!!! But I have an off topic question regarding speakers. There seems to be an overabundance of very intelligent people here, and I thought this would be the perfect place to ask!! I am trying to hook up two devices to one speaker and I dont want to get bleedoff back into the other system, how do I do this?

[mscoffman]

There seems to be an overabundance of very intelligent people here, and I thought this would be the perfect place to ask!!

A gentleman of obvious Insight!    and one of the more esoteric areas
of  electronics circuits. The thing you want is variously referred to as an
electronic hybrid circuit.

The following terms all reference the same sort of device;

echo cancellation/suppression, telephone sidetone generator,
telephone talkback suppressor, signal duplexor, audio hybrid circuit.

Without getting too complex here is a link to what you would like;

http://en.wikipedia.org/wiki/Hybrid_coil

There are three types of audio hybrid circuits;
a) Dynamic circuit involving amplifiers - absolute duplexor - requires ext. power
b) Passive circuit involving transformer signal cancellation - will not suppress small
power signal leakage (above link)
c) Roll your own using a 5V latching relay. - absolute switched connection


What I would do (this goes for big speakers not earphones.) is couple a hand
built power supply to each audio line via capacitors or audio transformers looking
for 3 to 5 Vdc to build up over a reasonable time period of low level audio. So,
isolation into a full wave bridge rectifier with some reasonable size electrolytic
capacitor (100uf) for dc filtering running into back to back zener diodes for
voltage limiting into a CMOS NE555. The CMOS IC would be set to pulse at 75
to 100ms. wide every 200ms rate. One for each audio channel with the NE555's
pulsing into a single 5volt latching relay. A latching relay has one coil for setting
and another coil for re-setting. The relay would enable whichever audio line's
NE555 was pulsing and the other would be disconnected. The relay would connect
the appropriate audio lines to the speakers and keep that pair connected forever
until that side was turned off and the other side audio was turned on. Because
the connection is a mechanical switch these units could be strung together and
represents total circuit isolation.

Link explaining latching relays;

http://en.wikipedia.org/wiki/Relay#Latching_relay

A link of circuit for explanation of relay function (only);
http://www.discovercircuits.com/PDF-FILES/LATCHRELAY1.pdf

TX2-L2-5V PANASONIC DPDT Latching Relay

http://parts.digikey.com/1/parts/753976-relay-telcom-latch-2a-5vdc-pcb-tx2-l2-5v.html

Now if we could just get someone to invent a method overunity energy production...

:S:MarkSCoffman

[Dr]

Mark: Thank you for the information!!! I dont suppose there is an off the shelf Item I could purchase?? As I am a mental midget when it comes to Electronics!!!

[mscoffman]

Sample Web Link;

http://www.amazon.com/dp/B0002ZSFA0/ref=asc_df_B0002ZSFA01121669?smid=AHF4SYKP09WBH&tag=nextag-ce-mp01-delta-20&linkCode=asn&creative=380341&creativeASIN=B0002ZSFA0

Type "automatic speaker switch" into Google.com

:S:MarkSCoffman

[Dr]

Thanks Mark: I will check it out!!!