Super Regulator

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#3,002
Do not use blue or white leds … they have high noise.
Green and red are the best choices. According to Christer’s test around 5 ma is best for noise .
The exact current for lowest noise varies. The LED voltage changes with the current. Walt fine tuned his designs using particular LEDs at a set current to get choosen output voltages and low noise.
 
#3,003
carlmart said:
So the problem is in using the LEDs or on which opamp you use?
Click to expand...
The problem is not with the LED's -- the opamp makes a big difference with respect to stability. I have used LME49710 (now discontinued), and the jfet AD825AR. NE5534 does not measure quite as well, but sounds fine. In my hot-rodded Adcom GFP565 I use AD825AR. It was quickly learned that the AD797 would oscillate in the 1995 design and discussed in the literature.

Also, the ESR of C6 in your simulation (650mΩ) is higher than that you would expect with a Panasonic FC (250mΩ). ESR also affects stability (see the two papers I cited above.) Do not bypass C6 with a ceramic.
 
#3,007
jackinnj said:
The problem is not with the LED's -- the opamp makes a big difference with respect to stability. I have used LME49710 (now discontinued), and the jfet AD825AR. NE5534 does not measure quite as well, but sounds fine. In my hot-rodded Adcom GFP565 I use AD825AR. It was quickly learned that the AD797 would oscillate in the 1995 design and discussed in the literature.

Also, the ESR of C6 in your simulation (650mΩ) is higher than that you would expect with a Panasonic FC (250mΩ). ESR also affects stability (see the two papers I cited above.) Do not bypass C6 with a ceramic.
Click to expand...
My proposal or my interest was to use LEDs instead of LM329 + zener as reference and to set the output , following what Grunf had commented. But not a specific LED brand & model. So I went ahead and made a sim with green leds that were listed on LTSpice.

About the opamps I simulated several, and the OPA 1611 suggested good results. So if you could make that test you suggested on the 1611 might be great help to many as it's a very affordable chip.

What I did not understand is the ECR of C6 on my simulation that you criticized, as I didn't specify any cap with 650mΩ ESR. In fact I was planning to use FC types for all caps.

I expected Jan to comment anything on using the green LEDs as I did, recommending it or not. But maybe he didn't see my question.
 
#3,015
Hello
In my quest to build the superreg from version 2.2, to provide an output of 24v, I have installed the following;

D5 change from LM329 to LM4040-10
D2(pos) and D7(neg): zener from 6.8v to a 12volt
R7/R14 = 1K
R6/R13 = 1.4K
caps 50v

voltages are 28.5v input to superreg

27v pos out
15.7 neg out
also led's do not light

any Ideas what has gone wrong
 
#3,016
jackinnj said:
Also, the ESR of C6 in your simulation (650mΩ) is higher than that you would expect with a Panasonic FC (250mΩ). ESR also affects stability (see the two papers I cited above.) Do not bypass C6 with a ceramic.
Click to expand...
OK, now've opened the C6 cap data sheet, which I never look into, and seen that the ESR specified for it is 600mΩ, as you said.

I don't remember what ESR Walt recommended for this capacitor, but I think it was an HFQ one.
 
#3,018
@esprit R6 should be 1.3k, but this is not the only problem. In your positive regulator, the power transistor is fully open, so the signal on its base is wrong. It may be because the opamp output is shifted all the way to one side or the zener polarity is reversed or the opamp is fried or the reference polarity is reversed. Measure voltages on the references, zeners, LEDs, opamp inputs and outputs.
 
#3,019
Hi everyone,

Recently I accidentally connected my Super Regulator to a wrong polarity of the battery power supply. The build instantly fried, the input cap exploded, and the opamp is gone. Oh well, it was an experimental build, no worries. I just need to make a new one.

To start out, I decided to switch from using a soldering gun to a soldering station, but I’m having the hardest time. I have a lifelong experience soldering and can make picture perfect connections, but I’ve never used a soldering station before. I’ve tried temperatures from 500 to 750 F (260 to 400 C). The solder is either like a paste or else burns and oxidizes, but doesn’t flow. It is frustrating like I’ve never soldered before in my life. Here is my setup:

Soldering gun: Hakko FX-650 (15W, Japan)
Solder: Oyaide SS-47 (4N-pure tin with 4.7% silver, Japan)

It runs a bit hot, OK in most cases, but for sensitive components I reduce the AC voltage by 10-20% using an auto transformer.

My new soldering Station is Hakko FX-888D (Malaysia) with the FX-8801 soldering gun (65W).

Can anyone please help me understand what I am doing wrong?

Thanks,
Alex
 
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