Given the spec of a LT3042
LT3042 - 20V, 200mA, Ultralow Noise, Ultrahigh PSRR RF Linear Regulator - Linear Technology
this board should be magic - just add a transformer, and get smooth, pure power.
Low-Noise LT3042 Linear Regulator Power Board DC Converter Overvoltage 5-20v | eBay
The components appear to be fairly "obvious"; 4 diodes, a big cap, an LT3042, and a PNP power transistor to handle the power.
I imagine the circuit is very much like the ones shown on page 26 of Linear's spec sheet ("Ultralow Noise Higher Current Regulator with External PNP").
All for £12.59.
Do I dash out and buy one, or is there a catch?
BugBear
LT3042 - 20V, 200mA, Ultralow Noise, Ultrahigh PSRR RF Linear Regulator - Linear Technology
this board should be magic - just add a transformer, and get smooth, pure power.
Low-Noise LT3042 Linear Regulator Power Board DC Converter Overvoltage 5-20v | eBay
The components appear to be fairly "obvious"; 4 diodes, a big cap, an LT3042, and a PNP power transistor to handle the power.
I imagine the circuit is very much like the ones shown on page 26 of Linear's spec sheet ("Ultralow Noise Higher Current Regulator with External PNP").
All for £12.59.
Do I dash out and buy one, or is there a catch?
BugBear
Attachments
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I have in mind to use it for the same purpose as you, in a HiFiBerry DAC+I have one.
It does not come with a nichicon cap. Some unknown brand.. I replaced unknown cap. Feeding 5v dc to dac analog stage.
It's ok.
Per:
DAC+ Pro - external power supply – HiFiBerry
But you don't sound at all taken with this board's performance. What's it doing wrong (or not doing right) ?
BugBear
Was it an upgrade for an existing PSU, or part of a new build?I've bought my board a few months ago. It came with a NOVER cap and it's used for powering up a DAC.
I have no complaints, it just does the job... However I have not done any other measurements but confirming the steady +5V output.
(i.e. are you in the lucky position to make a comparison?)
BugBear
Was it an upgrade for an existing PSU, or part of a new build?
(i.e. are you in the lucky position to make a comparison?)
BugBear
The set-up was/is Raspberry Pi and I2S DAC; the set-up was running an iFi iPower when I tried separate power feed for RPi (iPower) and I2S DAC (Chinese PSU)... The result was a marginal better sound definition (possible 'psychoacoustics' effect on my part) tested on integrated amp + speakers and headphone amp + quality headphones.
That sounds promising enough for me to gamble the £13!!The set-up was/is Raspberry Pi and I2S DAC; the set-up was running an iFi iPower when I tried separate power feed for RPi (iPower) and I2S DAC (Chinese PSU)... The result was a marginal better sound definition (possible 'psychoacoustics' effect on my part) tested on integrated amp + speakers and headphone amp + quality headphones.
BugBear
Yeah - I think the board is this circuit from LT data sheet (attached) with 4 diodes and a cap in frontBugbear,
LT3042 is nice reg. Board follows ordinary schematic. It's better than my other ps boards for sure.. I don't have any measurement or data. Only lt3042 datasheet and board components..
Thanks for your comments.
BugBear
Attachments
Just ordered one to try out. It can handle 1A because of the PNP pass transistor. A 20V input voltage maximum is not too limiting as the PSU is 3.3 or 5V output. It does not make much sense to use an LDO board with too high input voltages. As a PNP pass transistor has been used for more output current dropout voltage is approx. 1.5V. There are various toroid transformers putting out 7V AC which should be enough for 5V output. When being used for 3.3V output a 5V transformer will work fine.
The added PNP does not seem to make specifications much worse but paralleling LT3042 is technically better. You would need to parallel 5 of them though for 1A (or 2 x LT3045 in parallel).
Solutions - Increasing Output Current of the Ultralow Noise, Ultrahigh PSRR LT3042 200mA Linear Regulator
* It should be clear that current limiting and thermal shutdown protection are lacking. Short circuiting the output is best avoided (as always).
The added PNP does not seem to make specifications much worse but paralleling LT3042 is technically better. You would need to parallel 5 of them though for 1A (or 2 x LT3045 in parallel).
Solutions - Increasing Output Current of the Ultralow Noise, Ultrahigh PSRR LT3042 200mA Linear Regulator
* It should be clear that current limiting and thermal shutdown protection are lacking. Short circuiting the output is best avoided (as always).
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Probably at First try,I Connect the input voltage to output section of the board and destroyed The board.I changed The output transistor but it still doesn't work.
And probably I destroyed The main chip..
So if you try The board, BE CAREFULL about which side is input and which side is output!!
And it doesn't come with user manual
I took my
And probably I destroyed The main chip..
So if you try The board, BE CAREFULL about which side is input and which side is output!!
And it doesn't come with user manual
I took my
This board based on very simple "school book" schematic, only with little optimization.
The PNP pass transistor destroys PSRR (more at higher current), increasing of filter capacitors improves this.
Output impedance not outstanding, but adequate.
The PNP pass transistor destroys PSRR (more at higher current), increasing of filter capacitors improves this.
Output impedance not outstanding, but adequate.
Attachments
10 dB increase in PSRR making it 70 dB is still not bad. That is better than many other regs without a pass transistor...
Solutions - Increasing Output Current of the Ultralow Noise, Ultrahigh PSRR LT3042 200mA Linear Regulator
The board is not optimised, please see the original schematic in the link. The cheap chinese board lacks some parts and has some other values.
Solutions - Increasing Output Current of the Ultralow Noise, Ultrahigh PSRR LT3042 200mA Linear Regulator
The board is not optimised, please see the original schematic in the link. The cheap chinese board lacks some parts and has some other values.
Has anyone tried this low noise supply from DIYinhk?
0.8uV Ultralow noise DAC power supply regulator 3.3/5/7V 1.5A*x2 - DIYINHK
Parts quality is guaranteed, which seems not to be the issue on eBay kits.
It also has separate input series inductors before the caps, which would improve noise properly.
0.8uV Ultralow noise DAC power supply regulator 3.3/5/7V 1.5A*x2 - DIYINHK
Parts quality is guaranteed, which seems not to be the issue on eBay kits.
It also has separate input series inductors before the caps, which would improve noise properly.
Wow - different price point to the one I was looking at!Has anyone tried this low noise supply from DIYinhk?
0.8uV Ultralow noise DAC power supply regulator 3.3/5/7V 1.5A*x2 - DIYINHK
Parts quality is guaranteed, which seems not to be the issue on eBay kits.
It also has separate input series inductors before the caps, which would improve noise properly.
BugBear
Wow - different price point to the one I was looking at!
What was the price point you were looking at?
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