Super Regulator

[peranders]

Stability, with time and temperature but I think in a normal audio application it is not very important especially if opamps are used... except for nerds which require x.000 V and ppm in stability. Personally I think it's cool when I get unexpected precision. I have soldered a regulator, completely untrimmed, with 4.999 V out measured with a calibrated voltmeter

 

[jan.didden]

Agree. It is just a small deviation from the nominal 15V. Completely irrelevant in the grand scheme of things.

Also, the zener voltage for the zener in series with the opamp output is very uncritical. It is only there to make sure that the opamp output is somewhere around the middle of it's supply voltages, which here is gnd and Vout.

So for 24V, the zener on the opamp output can be anything between 5V and 18V, for instance. But if you are getting a 12V zener for the ref, that'll work also for the opamp.

Jan

 

[carlmart]

In my case it's 15v for both zeners, because I want a 30v output.

In fact that made it practically impossible for me to use a pre-regulator, as Walt suggested, because of the 35v input voltage some regulators need. Only if I regulated the input into the regulator, which should be crazy.

I also had considered using a CRC or capacitance multiplier filter before the regulator, which also gobbled more volts, making things plain foolish.

As it is now I plan to use a simple RC filter before the standard (I call it simplistic) Jung-Didden reg. And that's all.

 

[jan.didden]

There's a 60V version of the '317, the LM317HV.

Jan

 

[carlmart]

Walt recommended Panasonic HFQs for the regulator on his last (?) "tweak", in AE 4/00.

Second option were FC types, which are still being made.

Am I wrong or HFQs are not made anymore?

What other choices would you recommend that worked well on the superregs?

 

[peranders]

You can actually use regular caps with normal losses. Too good cap can cause instability.

 

[AudioDAC]

Superreg supply circuit

Hello.
I will build +-15V superreg for DAC opamp based output stage (Tweasted Pear I/V)
Is it enough to have simple shotky rectifier + Panasonic FC caps bank for superreg or the stabilised sypply is needed for better result?
thank you for help

There's a 60V version of the '317, the LM317HV.

Jan

 

[jan.didden]

You do not need a pre-regulator. Select a transformer that after rectification gives you between 22 and 28V DC. 2200uF after the rectifier is enough if you want to draw up to 0.5A or so.

Jan

 

[paulmarinis]

hello , can anyone please advise what should be the load to test the super regulator adjusted for 24V output?

 

[jan.didden]

Would it not be sensible to test it with the same load you intend to drive with it?

Jan

 

[paulmarinis]

yes , but just in case not to damage the circuit (ba-3 as a preamp)
without the load the output is 29V.

 

[jan.didden]

So you have a 24V superreg that outputs 29V with no load? That doesn't seem right. Load it with 1k to draw 50mA and see what it does.

Jan

 

[paulmarinis]

i just checked , with the load 1K i do have 24V, so i guess everything is fine?

 

[jan.didden]

Just to be sure, load it with 10k (2.4mA) and see if it is still OK. Should be.

BTW The 1k load is 24mA, not 50mA of course ...

Jan

 

[paulmarinis]

thanks alot for the help.
at 10K load the voltage is still 24V so i geuss everything is fine

 

[jackinnj]

WJ used a 137ma load -- i.e. 100R on 13.7V -- this might give you an exagerated measurement of output impedance.

I've settled on a 25mA current source -- this is the output of the PicoTest active load module.

 

[carlmart]

The green LED can be any green LED or an specific brand and model?

 

[jan.didden]

Ask yourself: what is the purpose of that LED?

Jan

 

[Joachim Gerhard]

Phonon

 

[jan.didden]

Un-darkner