Power amp under development

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#921
hoangduongo said:
I found that your DC detector is quite identical to the one from Silicon Chip, except some small change, I think it's because SC use 12V relay, I'll post that schematic later.
Click to expand...

Yes the DC detect circuit I posted has been used by at least 3 major electronics magazines in Australia for more than 25 years. It's simple and effective. See http://www.diyaudio.com/forums/showthread.php?postid=776114#post776114
I have changed some of the component values to suit my timing and operating voltage requirements.

Cheers
Q
 
#923
AndrewT said:
Hi Quasi,
can you correct the note from R1 to R2. Most will recognise the error but a few may be confused.
Click to expand...


Thanks Andrew,

Yes folks post 920 is incorrect. Please refer to this schematic.

Cheers
Q
 

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#924
Hi Quasi,
A time honoured circuit indeed. R1 is at least 1/2 that value in 120 VAC land. Your time constant should be on the order of 1/2 sec to 2 sec, before the relay timer connects.

If the amp suffers a failure, R1 is designed to burn out. This is very common in many larger amplifiers. Marantz, Denon and Nakamichi all come to mind (with R1 values ranging from 2R2 to 15 R).

-Chris
 
#925
Quasi, good work man, i just want to say I admire your work and design ,keep it up, I been abuilding amplifiers since I was in highschool (iam not an expert though) and Im planning to build this design of yours, could you please tell me how to adjust VR1 and VR2, the specs reading and the testpoints,, I really appreciate if you could tell me. Thanks again man.. Nice works 😉
 
#926
jhoel47 said:
... could you please tell me how to adjust VR1 and VR2, the specs reading and the testpoints,, I really appreciate if you could tell me. Thanks again man.. Nice works 😉
Click to expand...

jhoel,

I believe you will the document quasi created will be helpful. Please see Post #705:

http://www.diyaudio.com/forums/showthread.php?postid=955022#post955022


To rest on thread,

Sorry all but I am swamped with a number of family, personal and cat matters the past 3 weeks or more. I therefore have not been about to help out here and respond to some of the outstanding postings. Suitations may still take a few weeks to clear.


Regards,

John L. Males
Willowdale, Ontario
Canada
16 August 2006 03:10
 
#929
anatech said:
Hi Quasi,
A time honoured circuit indeed. R1 is at least 1/2 that value in 120 VAC land. Your time constant should be on the order of 1/2 sec to 2 sec, before the relay timer connects.

If the amp suffers a failure, R1 is designed to burn out. This is very common in many larger amplifiers. Marantz, Denon and Nakamichi all come to mind (with R1 values ranging from 2R2 to 15 R).

-Chris
Click to expand...


I guess the value of the resistor in question depends on a few other things too, ie; transformer size and the amount (number?) of capacitors.

Cheers
 
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