The simplistic Salas low voltage shunt regulator

[KMossman]

Originally Posted by AndrewT

if you need a Vref between 1.3V and 2.2V.

Two LEDs in series can work out better.

mmmmmmmmmmmmm usually the Vd for a [visible light] LED ranges from 1.6v [if I recall properly] or so to 3V or more................depends on color and type of LED

[Salas]

Most generic reds give me 1.8 to 1.92V these days, greens 2.1 to 2.2V, have older red and yellow ones in the 1.65-1.75V. Talking 2.5-5mA bias.

[Salas]

Originally Posted by ikoflexer

Measuring with the scope probe this way will always add some noise, in my experience. For critical measurements I always take the probe sheath off and use a very short solid copper wire from the scope probe to the load ground. Makes a big difference for sub-millivolt measurements. Hehe, your work brings back good memories.

Indeed. Those springy short path to earth bits come free in the bags of even $20 ebay "100MHz" at x10 probes and we better always save them somewhere, they come handy.

[johnm]

Originally Posted by johnm

After using the above shunt PCB with a DAC for quite some time for 5v output into a DAC, I have decided to re-use this shunt PSU for my Creek OBH-15 phono stage (24v 30mA required) as I no longer use that particular DAC.

A 5K trimmer, and 15R 5W current setting resistor will be substituted onto the shunt PCB, to enable setting 24v.

Whilst the Creek isn't the Highest of Fi, it's still pretty good, and will do until I finally get together all the parts for a Salas RIAA stage.

Until then, I'm seeing what effect using the above shunt reg will have on the Creek phono stage.

Just one question, I seem to remember reading somewhere in this thread (and I cannot find it after a search!) that for a transformer roughly AC volts in = DC volts out. So if I require to use this shunt for 24V output I assume I need to purchase a 2x12v transformer and wire it for 0-24v?

Have I got that right?

Many thanks

- John


P.S. Will I need heavier duty heatsinking than shown in the above picture to run this shunt reg PCB at 24v instead of the original 5V? Ta.

[Salas]

Yes to both questions.

[KMossman]

Originally Posted by Salas

Most generic reds give me 1.8 to 1.92V these days, greens 2.1 to 2.2V, have older red and yellow ones in the 1.65-1.75V. Talking 2.5-5mA bias.

thx. if I might add that the ultra-bright white LEDs can exceed 3V

[johnm]

Originally Posted by Salas

Yes to both questions.

Thanks Salas

John

[canvas]

Originally Posted by KMossman

thx. if I might add that the ultra-bright white LEDs can exceed 3V

If I remember correctly, there is noise consideration. White (blue) LEDs are noisier than red, green ones.

[Salas]

Originally Posted by KMossman

thx. if I might add that the ultra-bright white LEDs can exceed 3V

But not that usable in our referencing purposes here because noisy enough. Sure low noise and lowest Vf are IR LEDS.

[RCruz]

Originally Posted by johnm

After using the above shunt PCB with a DAC for quite some time for 5v output into a DAC, I have decided to re-use this shunt PSU for my Creek OBH-15 phono stage (24v 30mA required) as I no longer use that particular DAC.

A 5K trimmer, and 15R 5W current setting resistor will be substituted onto the shunt PCB, to enable setting 24v.

Whilst the Creek isn't the Highest of Fi, it's still pretty good, and will do until I finally get together all the parts for a Salas RIAA stage.

Until then, I'm seeing what effect using the above shunt reg will have on the Creek phono stage.

Just one question, I seem to remember reading somewhere in this thread (and I cannot find it after a search!) that for a transformer roughly AC volts in = DC volts out. So if I require to use this shunt for 24V output I assume I need to purchase a 2x12v transformer and wire it for 0-24v?

Have I got that right?

Many thanks

- John


P.S. Will I need heavier duty heatsinking than shown in the above picture to run this shunt reg PCB at 24v instead of the original 5V? Ta.

Hi John

Is this a BiB clone ?