The simplistic Salas low voltage shunt regulator

[merlin el mago]

I have 1 choke common mode 2x2mH 3A 250V, could I use it or do you recommend only RCRC?

 

[Salas]

Where can I buy, is to be installed at the probe, how much cost?

Its usually in the probe accessories when buying a new probe. Along with channels color rings & square wave alignment plastic screwdriver. But you can make from wire or maybe find on line as "ground spring". Example: PK1-5MM-118 Teledyne LeCroy | Test and Measurement | DigiKey

It goes on like this:

 

[Salas]

I have 1 choke common mode 2x2mH 3A 250V, could I use it or do you recommend only RCRC?

It could be LC also, yes. You put between reg & FF, LC or RC, and watch scope for if it helps and for manipulating to best result.

 

[merlin el mago]

I will do tomorrow and let you know, now it's too later, for C values the mains filter cap that I have now is 2.200uF, have to use another one the same value 2.200uF or can I use some small value, or it's important keeping both caps the same value?

 

[Salas]

For rail RC filter maybe 10R 1000uF will show where it is going for better noise or not

 

[merlin el mago]

Ok I will try 1st RC and test with the scope.

Thanks & good night Salas.

 

[merlin el mago]

Adding RC 10R 1000uF at PSU before the R-D🙂

 

[merlin el mago]

Adding LC choke common mode 2x2mH 3A 250V 1000uF at PSU before the R-D🙂

 

[Salas]

Was the FF also on for those pictures?

 

[merlin el mago]

Yes FF + isolator

 

[merlin el mago]

Can be mornings AC mains are less poluted?

 

[Salas]

So you have raw DC outboard of the regulators and you tried the rail filtering in-between the raw and the regulators?

 

[merlin el mago]

Yes.

 

[Salas]

FF rather easily picks EMI. If the Vout rail will remain so good on the scope, then win win. I.e. the filter worked and not necessarily put at the end point imposing its capacitor characteristic to Vout

 

[merlin el mago]

What do you prefer LC or RC?

 

[Salas]

I don't see difference on the scope, so listen for it to decide. LC sometimes is preferable on analogue applications but I don't know what a Flip Flop can care for

 

[merlin el mago]

L is common mode so more filtering than L alone.

 

[Salas]

Leave it there then. It does not look worse than with the RC on the scope for sure. But the scope is not AP analyzer to show deeper differences.

 

[merlin el mago]

Time to listening.

 

[Salas]

Best time is listening time