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5V 3A PSU

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Ash View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ash Quote  Post ReplyReply Direct Link To This Post Posted: 26 Aug 2019 at 11:12pm
9-15V 3A on the back of pre-production units. So I would have to buy two or three of the PSU and link them in order to use it for this purpose?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 06 Sep 2019 at 9:47am
The power supply is now with John who will be dismantling it to see how to put it together, and documenting the parts. It should then go to Rob who will deal with case engineering and finishes.
That none should be able to buy or sell without a smartphone and the knowledge in how to use apps
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mhamilton Quote  Post ReplyReply Direct Link To This Post Posted: 26 Sep 2019 at 4:22pm
A couple of notes/questions
1) Wondering why you don't favor torroidal transformer like the popular Talema units ? 
2) LT317A is an alternative regulator.  Specs show slightly lower output noise.  Not sure its significant. 

Hope progress on the hardware goes well. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mhamilton Quote  Post ReplyReply Direct Link To This Post Posted: 26 Sep 2019 at 4:30pm
I apologize -- I see torroidal hum and buzz are problem. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 26 Sep 2019 at 5:30pm
Originally posted by mhamilton mhamilton wrote:

A couple of notes/questions
1) Wondering why you don't favor torroidal transformer like the popular Talema units ? 
2) LT317A is an alternative regulator.  Specs show slightly lower output noise.  Not sure its significant. 

Hope progress on the hardware goes well. 


LT317A is 1.5 amps according to its data sheet
That none should be able to buy or sell without a smartphone and the knowledge in how to use apps
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 26 Sep 2019 at 5:39pm
Originally posted by mhamilton mhamilton wrote:

I apologize -- I see torroidal hum and buzz are problem. 


It is the capacitive coupling of high frequency mains garbage onto the secondary which after a number of days usage stamps a brittle sound on whatever it powers, digital or analogue. The reason for this delayed result is the time it takes for the "newness" of capacitive components to "wear off" and the transformers seem to become more effective at coupling mains garbage over time.

The dual bobbin e-laminated transformer has much lower interwinding capacitance.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote BAK Quote  Post ReplyReply Direct Link To This Post Posted: 26 Sep 2019 at 6:05pm
Originally posted by Graham Slee Graham Slee wrote:

Originally posted by mhamilton mhamilton wrote:

A couple of notes/questions
1) Wondering why you don't favor torroidal transformer like the popular Talema units ? 
2) LT317A is an alternative regulator.  Specs show slightly lower output noise.  Not sure its significant. 

Hope progress on the hardware goes well. 


LT317A is 1.5 amps according to its data sheet

 I had asked the same question of Graham years ago.  

 Just a clarification;
Looking at the specs for the LM350A, it has the same power supply ripple rejection as the LM317A... 
 86dB with 10uF on the adjustment pin on both.
LM317A is rated @ 1.5 amps max, ( LT317A is similar)
the LM350A is rated @ 3.0 amps max.

The LM350A is needed for its higher current here.

Knowing Graham has design prowess in power circuits, he has more techniques to design a power supply with minimum ripple and noise.


Edited by BAK - 26 Sep 2019 at 6:11pm
Bruce
AT-14SA, Pickering XV-15, Hana EL, Technics SL-1600MK2, Lautus, Majestic DAC, Technics SH-8055 spectrum analyzer, Eminence Beta8A custom cabs; Proprius & Reflex M or C, Enjoy Life your way!
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