The simplistic Salas low voltage shunt regulator

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#2,081
''Force'' are the main output rails, and main output grounds yes. Exactly like you describe it is wired in the pictures. Sense + core, sense return shield. In this case his coax is a loudspeaker coax and its core is thick, so he used it for force too. Not necessary for force. To use shielded for sense is required. It takes away noise that can be seen or not in slower oscopes. But can be seen on non sinewave only wide bandwidth voltmeters. The main ''force'' cabling can be a twisted pair. RG58 can do for sense. The sense will ''see'' the end nodes of the force with the added cable shortcomings, but will not return heavy currents itself. So it can be thinner.
 
#2,082
I have learnt something from that picture.

I previously thought I would use a shielded sense wire, disconnect the shield on the load side, and connect the shield to the ground on the regulator side, and use a seperate non-shielded wire for the ground sense.

The picture shows a better way to do it by simply using the shield as the ground sense wire, saving one extra wire.
 
#2,083
I have a bit of problem though.

The good quality shielded interconnect cables are usually hard and difficult to be bent so they are difficult to work with, so I choose the smaller and thinner ones that are far more flexible, but the shield only consists of perhaps a dozen or two very thin "hairs" so I am not sure if they are good to be used for the ground sense wire.

I have never found any thicker interconnect cables that are flexible enough for PCB work.
 
#2,084
Use RG58 on all your shunts for sense wiring. Use as thick main ''force'' wiring as you like. Remember that the sense nodes are voltage nodes, don't worry about gauge. Their mission is to skip the voltage drop on the current carrying force wires and ''see'' the remote nodes directly. I believe that you will see less stuff on your scope in difficult termination situations if you shield your sense wiring. If you need extra thin and flexible enough, see about Belden (RG style) 179DT also, which I like for signal too BTW.
 
#2,093
They go around 62V after rectification in practice, like being 2X22V, still need a 10R resistor before cap, and they don't lose easily, very good regulation. If the 2X18V 80VA model goes 2X19V in reality, it would be best for about 53-54V and to avoid the resistor.
 
#2,097
I got one from Selectronic and use it inside my pre case without any induced hum issues.

Shorter wiring between PSU and shunts also sound better. (My previous project used toroids and I had to store them in and outboard PSU to avoid induced hum.... The long wires between psu and pre add some dullness IMO.)
 
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