What load does the supply see for LM1875?

[AndrewT]

Have you considered start up?

 

[geraldfryjr]

Don't you think one of the following circuit can handle both LM1875s. The transistor is MJE3055T (10A max collector current) and diode 1N5407 (3A max). Thus theoretically I should be able to supply about 10 A at 40 V ? The resistors will be 300 and 10K.

That circuit in post #13 does not provide very good regulation see this thread,

http://www.diyaudio.com/forums/chip-amps/261125-lm3886-problem.html#post4037783

This is much much better,

http://www.diyaudio.com/forums/chip-amps/261125-lm3886-problem.html#post4064510

I have a final version later in the thread although I have not made one yet for a 45v to 60V input voltage at 10 amps.

Here it is,

http://www.diyaudio.com/forums/chip-amps/261125-lm3886-problem-2.html#post4073963

jer

 

[Arty]

I have a stereo system with 100W trafo giving 2x19V regulated to 22V with 2 lm338 that can deliver max 7A (they also mention 12A). Didn't have any problem yet and don't think I will. Although I use it with a 8 ohm bookshelf speaker.
You should not put big caps after regulators, max they advise is 1000uF. I have 100uF. And 9900uF before the reg.
http://www.diyaudio.com/forums/chip-amps/79303-chip-amp-photo-gallery-239.html#post3416070

By the way regulators will not like 58V supply voltage. Lm317 or 338 doens't like more than 40V.

the input-output difference must not be higher than 40 volts.
perfectly fine as it is.
caps after regulators will have a surge on poweron, but it should do no harm if the caps are not superhuge.

 

[iinself]

Have you considered start up?

I did not even think about that, thanks.

 

[infinia]

^This guy has 3 or more threads open, concerning the same thing
(he's acquired an old AVR receiver and wants to build sumptin easy)
noobs don't know enough to ask the right questions, so now he's got about a half dozen of you DIYA folks twirling about. haha

correction 4 threads now and a dozen regulars contributing.

 

[abraxalito]

(lost)

 

[infinia]

Hi,
how can I find out what load is presented to the PSU by LM1875 driving a 6ohm speaker.

Thanks

Dude what's up with all these threads open at once?

rather than asking open ended type questions all over the place why don't you give us some background info 1st!

 

[iinself]

Dude what's up with all these threads open at once?

rather than asking open ended type questions all over the place why don't you give us some background info 1st!

I did not know that starting a few threads simultaneously was not the proper thing to do, I can refrain from that if it as problem. My thinking was since they were different topics I would start a different thread.

 

[danielwritesbac]

I didn't experience any pain, mainly because the threads posted were all related; however, I was curious as to the widespread broadcast. I didn't actually find it unsuitable, but merely unusual.

 

[Arty]

i agree with daniel.
every thread has its own value, and while it is whitin the same project i would nto merge them. as none of the thread titles do any match every content.

i think it is fine as it is.
like posting 1 thread about powersupply, one thread in chipamps about a particular power amp, and one in the line level stage for an EQ /preamp or something like that.

same here.

 

[Mark Whitney]

It is combination of Mission Impossible and Scrapheap Challenge.