Thursday, March 1, 2012

Speaker protection with uPC1237

I was using IC uPC1237 for speaker protection in almost all my power amplifiers, because schematic is very easy to build with few external components.



Here is the latest version of the schematic that I use:



A transistor and LED were added to indicate when speakers are switched off.
The whole part with RT1, RT2, T2, J1 and RLED is optional and protection module will work without them.

The C1 value may be increased if there is false activation with high output signal level from amplifier.
With these values of elements schematic will work with 24VAC, 34VDC, and will activate when there is more than ± 2VDC in output signal. Initial mute time will be around 3-4 seconds.
There are formulas in the schematic to calculate the values of the resistors for different supply voltages.

Jumper JP1 is used to set two different modes of work. If jumper is shorted the module will be in automatic resetting mode. If jumper is not connected then module will be in latching mode. For more details please read the datasheet of the uPC1237.

Bellow is a diagram how to connect speaker protection module with an amplifier.




A little older version of the protection module.


Here is a link for downloading an archive with PDF files of the project: DC Protection.rar
Use it on your responsibility.

8 comments:

  1. Здравей, как мога да се свържа с теб искам да поръчам една такава защита, интересуваме цена и дали ще работи при 38VDC.
    Поздрави, b0n3v :)

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    Replies
    1. Виж на страница "About".

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    2. С голямо закъснение пиша, но човека е много точен, защитата работи коректно, без проблем вече доста месеци, добра покупка.
      Препоръчвам!

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  2. This comment has been removed by the author.

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  3. I haven't tried it yet çause I need the parts list.
    Can you please post them.

    Thanks much

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  4. This is the best PCB for uPC1237 that I found on the net. It's compact and I like the way that the relay arcs to ground instead to the speaker. I built it with the same relays (RAS 1215) and it functions perfectly.

    Regards

    Ivan Lukic
    Serbia

    ReplyDelete