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In circuit #1 I showed typical adjustable power supply usage it can limit voltage and current, all good.

It got me thinking. Let's say due to some reasons I can't replace battery with a power supply but I can connect it in series like showed in circuit #2. If I set power supply voltage to 0V (to keep same voltage) and current limit to some value.

Would it limit the current? Can I damage power supply by doing it? If I set positive or negative voltage would it still work the same?

enter image description here

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  • \$\begingroup\$ Yes, quite possibly and no. \$\endgroup\$ – Andy aka Aug 22 '20 at 18:29
  • \$\begingroup\$ That's about it..... no Specs, no idea. Maybe if you put Python in series with C++ you get a vitamin snake. \$\endgroup\$ – Tony Stewart EE75 Aug 22 '20 at 19:56
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  • A current source is defined as high impedance has no voltage regulation with the load.

  • A battery is defined as a voltage source with low impedance has no current regulation with the load.

  • When the two are in series, you still have a current source ( or sink if on the low side)

  • Unless the current is limited and voltage limited to match the load exactly, you have no regulation. But this is done with LED strings designed for the CC source.

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Conceptually, yes. But if you want to do this with a real DC-DC, then you would need to verify whether it is capable of operating the way you describe. I have not seen DC-DC converters that were designed to operate at 0V. But it should be possible to design one that does that. It would need to have connection to Batt+ and Batt- in order to bias up its internal circuitry.

It seems like it would be better to just design a current limiter circuit. Maybe put some kind of microprocessor in there to control everything.

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  • \$\begingroup\$ Can you clarify what do you mean by saying "It would need to have connection to Batt+ and Batt-". Does it mean that is has to be connected in parallel? If so do I connect Batt+ to DCDC+ or DCDC-? "it would be better to just design a current limiter circuit" so if I understand correctly in circuit #2 if I change power supply with electronic load in constant current mode it should limit the current as expected? \$\endgroup\$ – Combinacijus Aug 25 '20 at 19:40

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