Super Regulator

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#641
Hi
I have attraction dac and small amp which is 2 x 10 Watts of Power into 8 Ohm or 2 x 20 Watts into 4 Ohm.
Dac is 12v 200mA
Amp is 12v ???A
I want to build 2 psu for them by using Jan didden regs.
3A for amp will be definitely ok..
It is working with a 12vdc 1A cheap wall adapter now.
I don't know maybe it is not work with 1A Jan didden reg..
What is the max amper value while keeping the design mostly original?
I have no electronic knowledge!!
Can you tell me what are the exact material list to power my dac and amp?
Such a list like amb lab psu s.
I will buy the PCB boards with my next salary..
Help please?
 
#642
Hi all,
I am building the 2.2 board to use with a B-3 preamp. I am having trouble locating the 6.8 Zener at .25w (if I am looking for the correct thing). Will this 5.6v at .25w work? The Mouser part number is 610-1N4626
Thanks for any help. I feel like such an idiot dealing with all of this...
 
#646
#647
Hello there,
I need for my Dac only positive voltage, it is possible.
Input voltage ~ 17,00V output voltage 12,00V current ~ 450mA
Input voltage ~ 12,50V output voltage 5,00V current ~ 380mA
How do I calculate the resistors to the voltage to fit?
Thank you.


Hallo,
ich brauche für meinen Dac nur positive Spannung, ist das möglich.
Eingangsspannung ~ 17,00V Ausgangspannung 12,00V Strom ~ 450 mA
Eingangsspannung ~ 12,50V Ausgangspannung 5,00V Strom ~ 380mA
Wie berechne ich die Wiederstände um die Spannung an zu passen?
Danke
 
#648
Dirk1 said:
Hello there,
I need for my Dac only positive voltage, it is possible.
Input voltage ~ 17,00V output voltage 12,00V current ~ 450mA
Input voltage ~ 12,50V output voltage 5,00V current ~ 380mA
How do I calculate the resistors to the voltage to fit?
Thank you.


Hallo,
ich brauche für meinen Dac nur positive Spannung, ist das möglich.
Eingangsspannung ~ 17,00V Ausgangspannung 12,00V Strom ~ 450 mA
Eingangsspannung ~ 12,50V Ausgangspannung 5,00V Strom ~ 380mA
Wie berechne ich die Wiederstände um die Spannung an zu passen?
Danke
Click to expand...
Which circuit are you using?
Post a sch and then a Member can help you through the resistor selection process.
 
#649
#651
Finished building the Jung (Didden) super regulator with LM317/337 prereg last night. Tested it with resistor load running at 50mA with 21VAC input to the LM317/337 and 17.8VDC input to the Jung reg and 15.4VDC output. No noise was measured at the output with a 150MHz 2mV scope.

Noticed that the light of LED on the positive rail died quickly when switched off, but the light of the LED on the negative rail flashed a few times before dying down. This was repeatable every time. Checked that the regulator still worked after switching on and off a few times.

Why flashing LED light when turned off?

Also, the intended output voltage was 15VDC. The resistor pair to determine the voltage was based on AWL's data. It turned out to be 15.4VDC. I don't mind the higher voltage, but am wondering why AWL's calculation doesn't fit here.
 
#653
peranders said:
If you use a LM329 then you'll have ±5% tolerance so you have to adjust the gain accordingly
Click to expand...
That was my experience.

However, this provides an opportunity to have some fun with algebra, for those people who can imagine algebra being fun. I understand that many people cannot.

Turn this into a design problem and use algebra to solve it:
Jane has a SuperRegulator that uses an LM329 as a voltage reference. Her desired output voltage is 16.3 volts (or call it "V" volts). She wants to design the feedback resistor network to include a 20-turn trimmer potentiometer whose nominal value is one of these standard values {50R, 100R, 200R, 500R, 1K, 2K, 5K}. She wants to choose a potentiometer value AND the values of the two fixed resistors, such that the output voltage tuning range is guaranteed to include 16.5 ("V"+0.2) volts and is also guaranteed to include 16.1 ("V"-0.2) volts, even when the LM329 is at the ends of its ±5% tolerance band. Furthermore she wants the DC bias current flowing in the feedback resistor network to be no less than 5mA and no greater than 10mA. Choose a potentiometer value and an upper resistor value and a lower resistor value, which meet these constraints.
​
 
#656
I think if using a BJT opamp then the +in and -in input impedance need to be matched. That requires some algebra to calculate the values of the resistor pair for the desired voltage, after knowing the actual LM329 voltage.

If using a JFET opamp like the AD825 I am using, perhaps matching the input impedance becomes less important, and I could just reduce the upper resistor to get the desired voltage, instead of reducing both resistors in the right ratio.

But in this instance, I would be happy to live with 15.4VDC.
 
Last edited:
#657
I don't have the LM317/337 prereg wired in the way as in Jung's schematic. I am simply using a standalone LM317/337 regulator as the prereg.

I will be using the Jung Super Reg for some opamp circuits. I have set the LM317/337 output to be +/-17.8VDC because most opamps have maximum voltage of +/-18VDC. So in the case that the Jung Super Reg failed, the maximum voltage placed on the opamps would be +/-17.8VDC, which is still safe for the opamps.

17.8 - 15.4 = 2.4. Is 2.4VDC voltage drop for the Jung Super Reg optimal, considering its DC input?
 
#659
I plugged in the Jung SR yesterday. There is a mark improvement on the sound quality comparing to using the old power supply. Noise level has dropped. Background is cleaner. Music has more details and instruments more textures.

The load is an active crossover for dipole speakers consisting of 12 single opamps for left and right channels of 6 buffer stages. I built the load board without using 0.1uF X7R and without larger size low ESR electrolytic capacitors. I installed 0.1uF C0G + 1R, 0.1uF C0G + 0.22R, and 2 x 22uF (Z=0.4R) at the load. The output cap for the Jung SR is a 47uF. So the total capacitance distributed across the SR output and the load is 91.2uF, close to the original 120uF specified.
 
#660
The heatsinks for the D44/D45 were measured at 45 degrees, 20 degrees above ambient temperature.

I installed a 300R /2W resistor from each rail to ground at the output of the SR to guarantee the current load to be a minimum of 51mA. I guess without some minimum amount of current load the SR won't have super low output impedance. On 15.4VDC rails this 300R resistor dissipates 0.8W power. I measured the temperature of it to be 65 degree.

Is this 65 degree temperature worrying? It makes the output ground track hot as well. The small can 47uF output capacitor is affected by it. The output capacitor was measured at 45 degrees, as hot as the heatsinks.

Do you think it is OK?
 
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