[tomb]

  I can not see the pic at all!! Are there anyway to recover it? PLease help im really interested at this.
 
Thanks,
Jill 

 
I've replaced most of the photos in my posts.  I'm sorry to say that I lost the original _redruM schematics.  This post about Trickle Chargers occurred before the infamous Head-Fi hack several years ago.  Links and photo locations were lost for all posts that were before that date.  Anyway, there should be plenty there to make sense for everyone, now. 

 

[NiHaoMike]

  By the way, it's not difficult to modify the PIMETA v2 LM317 trickle charger to let the wall supply run the amp when on wall power, bypassing the battery:
 
 
 

Unlike the one you show, the LM317 isn't regulating the wall power supply, so you'll want to use a reasonably clean wall supply if you go this route.

What about put the diode between the output of the LM317 and the circuit output? That point will be 1.25V above the battery voltage with the charger connected.

 

[tangent]

I'm not sure exactly what you mean, so why don't you draw it?
 
Then, before posting it, consider carefully what the voltages will be under the various conditions. I suspect you'll find that there is a path with your idea that causes problems.

 

[NiHaoMike]

With the charger connected, the 317's output will be 1.25v above the adj pin which is connected to the batteries, so the diode will conduct it to the output. The other diode from the batteries to the output will be reverse biased and have no effect. Only way you'll get problems is if the load draws too much current for the 317 to handle.
 
Without the charger connected, that point will be slightly lower than the battery voltage when the load is drawing current, maybe 100mV or so worst case. That's not enough to cause any problems, since it takes another diode drop to make current flow through any parasitic diodes in the 317. If you're really worried about it, use two series diodes (will also reduce the load voltage difference with and without the charger connected) or use a Schottky from battery to output.