I've been beating my brains out in a circuit I attached a figure below. Well I have 2 current transformers(CT). First from current on secondary 100A:50mA and second from voltage on secondary 100A:1V. In my first CT, I need to add burden resistance to measure current on secondary and add an offset of +2.5V because of my ADS1115 (16 bit ADC) Im going to read on its analog input, however for second CT I just need to add offset. About this circuit its done and you can find more info to get update about my following problem:


I want to know if is possible to have 1 KRE 2 connector on the board im going to design and when I connect 1º CT (100A:50mA) on my KRE 2 connector I should select its circuit (with burden resistance) and then go to my A0 ADS1115 input while my 2ºCT keep disconnect of course. However, if I wanna plug my 2ºCT on my KRE 2 connector, I need to switch for its circuit and then go to ADS1115. Signal track for ADS gonna have 2.5V because my offset. I just would like to know how to do it automatically if possible just using analog components. Any doubt, let me know


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    \$\begingroup\$ Ahem! Isn't this a duplicate of Analog Automatic selection circuit Switch \$\endgroup\$ – Andy aka May 23 at 15:05
  • \$\begingroup\$ If you need any precision in your current measurements, it may be a good idea to use a voltage reference IC for the offset, instead of a resistor divider. You know you can get reference ICs with two outputs, one exactly twice the other, so you can feed in (for example) 5V to your MCU's reference input and 2.5V to that offset. \$\endgroup\$ – Hearth May 23 at 15:56
  • \$\begingroup\$ Hearth, can you link me a voltage reference you recommend, please? what about "you should never leave the secondary of a current transformer open-circuit while there's current passing through the primary. " do you think that is possible to figure out this too? \$\endgroup\$ – Didan Junqueira May 23 at 16:45
  • \$\begingroup\$ @Andyaka they are different problem solution. First I should use female stereo plug and this one just kre 2 connector \$\endgroup\$ – Didan Junqueira May 23 at 16:46
  • \$\begingroup\$ If you have additional information related to your original question, use the "edit" button to add the information there. Do not create a duplicate question. \$\endgroup\$ – Dave Tweed May 23 at 18:20

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