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build your own bridging module

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=133649
Printed Date: May 12, 2024 at 7:32 AM


Topic: build your own bridging module

Posted By: fuster
Subject: build your own bridging module
Date Posted: February 20, 2013 at 10:02 PM

Do any of the gurus on this site have the know how to suggest to me a way to build my own bridging module for an early generation Orion amplifier?

I just bought a 4100gx and the manual states I must use a bridging module to bridge two of the channels. Not going to do this soon, but I would like to have the option in the future.

Thanks,

Mike

-------------
Chronic, late stage optimist.



Replies:

Posted By: i am an idiot
Date Posted: February 20, 2013 at 10:50 PM




Posted By: oldspark
Date Posted: February 20, 2013 at 11:37 PM
Isn't that an "input" bridge (2 into 1 or 1 to 2 etc) as opposed to an input inverting bridge to phase the bridged outputs?
(eg SiliconChip/Jaycar's Bridge Mode Adaptor for Stereo Amplifiers)




Posted By: i am an idiot
Date Posted: February 21, 2013 at 5:18 AM
That device inverts the right channel just as the Orion Bridging module works. Orange = Bridge positive, Yellow will be bridged Negative.




Posted By: fuster
Date Posted: February 21, 2013 at 7:24 PM
I used the link. It gave a page with error scripts. I used the one link that was working on that page and it took me to a page entitled: "DIN Bridging Module".   

I looked. I am afraid I don't read all the stuff well on there, but it appears it is a diagram to put something miniature inside the DIN male plug? That is TINY! Or, am I reading it wrong? Sorry for being so dumb on this, but if I know what it says, I am a competent person with a soldering iron and solder! I just have to know what exactly I need to purchase for the parts, and how I am to hook them up.

-------------
Chronic, late stage optimist.




Posted By: oldspark
Date Posted: February 21, 2013 at 8:43 PM
LOL! I'm the dumb one - I didn't even see the SMD OpAmp small device. (I auto-downloaded the link but it missed the .swf... d'oh - see, I am an idiot #2!)

Hence Dear i am an idiot Esq, forgive my reply above. I thought it was mere resistor bridging (and after your reply thought the amp had inverting inputs...) (Yours sincerely, IAAI#2.)


fuster - information is somewhat lacking on that link.
There is a section on Op-Amp Inverters at https://www.bcae1.com/opamp.htm but it doesn't quite tally with the circuit on the earlier linked .swf which is probably using the LM358/LM2904. [It needs to be a single-supply OpAmp as opposed to those that require a balanced +ve & -ve supply around 0V (GND).]   
[Locate sections like the abovementioned Operational Amplifiers by scrolling down the RH side of the bcae1 home page bcae1.com, eg #51 Amplifier Bridging, #82 Operational Amplifiers, etc.]

Maybe IAAI Esq. can provide the required detail... ?

BTW, that bcae1 DIN bridging module/cable is a simplified equivalent of the SiliconChip July 2008 Bridge Mode Adaptor which uses an equivalent LM833 OpAmp.




Posted By: fuster
Date Posted: February 21, 2013 at 9:06 PM
Hey, well, I contacted the seller of the bridging module in the first post with the link to a seller. Here is what he told me:

Hi Mike,

Thank you for your enquiry.

Unfortunately, this unit will not suit car amplifiers as it requires a dual rail power supply.

OK, well, it sounds as though I still have to hunt on that "bcae" web link to find the right bridging module?

-------------
Chronic, late stage optimist.




Posted By: oldspark
Date Posted: February 21, 2013 at 10:01 PM
It's not my day for NOT being an idiot. Or is it just this thread?
Talk about me being confustergated (as in "confustigate the muddy bucket of pitch"... ah - maybe it's you? posted_image

That SillyChip & LM833 uses a dual supply (I called it balanced above).
And IMO that is required due to the audio signal swing above & below GND.
There are ways to use a single-supply OpAmp, but IMO based on that BCAE circuit the DIN pins must therefore have +ve & -ve rails (supplies).

Again, maybe i am an idiot can confirm or supply extra info.
I think I'll butt out of this thread...

Though before I do...
I recently decided that a dual supply is not that difficult. I have a box of 12V cig-socket chargers for mobile phones etc that I convert for other voltages. Some seem to be dual else split supply outputs, but if not, they are relatively easy to modify for dual supply outputs. (Though I suspect keeping to a 3V-8V (and hence +/-3V to +/-8V) output is easiest to avoid "up" conversions.)
That came about because for ages I've been wanting to use some Tamura current sensors/transducers (from DigiKey) for misc vehicle tests and monitoring.
Though the Tamuras have +5V versions which would be easiest for vehicle DC systems, the output is unsuitable for connection to cheap panel meters since the output is centered around +2.5V (for 0 Amps).
I decided the best solution was to use the +/-15V dual supply Tamuras so that a common LCD etc voltmeter panel could be used without any level shifting. (The +5V version is suitable for "intelligent" inputs - eg, uPCs, PICAXES etc - the +2.5V "zero" point is merely mapped as being zero Amps.)

A dual supply audio inverter could use the same. In fact its low current might even mean that simpler "primitive" transistor & capacitor converters could be used.

But I'll let the audio experts hereon provide their solutions.




Posted By: Ween
Date Posted: February 21, 2013 at 10:04 PM
Hi,
Your amplifier probably has the dual rail supply inside it...powering the preamplifier portion of the amp. Careful probing/circuit identification will be required. Or a small dc/dc converter, once power requirements of the bridging adapter are known.
Mark




Posted By: i am an idiot
Date Posted: February 21, 2013 at 10:21 PM
Ween is correct, your amplifier does provide + and - voltage needed by that other bridging module. Positive voltage is on pin 1 of the din plug. Negative voltage is on pin 3 of the din plug.





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