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If I use the above rail-splitter with a 24V non-isolated power supply, what can be the problem when used with any load like an opamp ect.?

How would the current loop if the power supply is not isolated through the earth and cause problem? (Please illustrate the current loop if possible.)

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    \$\begingroup\$ How is this question different to your previous one: electronics.stackexchange.com/questions/333896/…? \$\endgroup\$ – Transistor Oct 16 '17 at 13:11
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    \$\begingroup\$ What do you think will happen if the 24V ground and the virtual ground are connected to the same node? Take a minute to think about that. Conclusion it is essential that the virtual ground ..... connected to the ground of the 24 V supply. \$\endgroup\$ – Bimpelrekkie Oct 16 '17 at 13:15
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    \$\begingroup\$ This does not mean that the 24 V supply cannot have a (mains) ground connection. That would still be OK as long as the virtual ground on the right is not connected to it. If you do want to connect the virtual ground to mains ground then the 24 V supply must be a floating one. \$\endgroup\$ – Bimpelrekkie Oct 16 '17 at 13:30
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    \$\begingroup\$ @Trevor Now really settled, promise no more trash \$\endgroup\$ – user1245 Oct 16 '17 at 16:03
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    \$\begingroup\$ @user134429 :) Just pulling your leg \$\endgroup\$ – Trevor_G Oct 16 '17 at 16:06

If the true ground connection at the power supply is the ONLY ground connection it will not be a problem.

The real issue comes with what you do with your signal outputs. Consider the schematic below.


simulate this circuit – Schematic created using CircuitLab

A simplified version of your virtual ground circuitry is shown on the left with the power supply grounded on the negative pin. That part should work as expected.

However, when you feed the output if the first circuit to a second box, or somewhere else in the same box, and that second part also has a ground connection to the real ground you create a short between your virtual -12V and ground.

At that point, at best, the circuitry no longer functions as expected, at worse you can exceed the input voltages on the right hand circuit and burn something.

If your left hand circuitry is stand alone and does not connect to any other device, then power supply isolation should not matter. I say should, because if your power supply is not isolated and your gizmo is in a metal box that is grounded, you need to make sure the virtual ground does not touch that case anywhere.


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