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I'm designing a short-circuit protection circuit for x2 AA battery (3V) and I'd like some tips from the community on how can I make it a low power mode circuit.

When V_out is short cirtcuited, the buzzer is activated. The problem is that the power consumption, when there's no load, is located at the 10k resistor. I'd like some tips on how can I make it a better designed circuit.

enter image description here

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  • \$\begingroup\$ The other 2 resistors are dissipating much more power then the 10K. What makes you think the 10K in particular is a problem? \$\endgroup\$ – Unimportant Oct 20 '20 at 18:59
  • \$\begingroup\$ power dissipation on R3 has nothing to do with the load! \$\endgroup\$ – Hamid R. Tanhaei Oct 20 '20 at 20:27
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There's even more current flowing through the R1 and R2 than R3.

The R3 could be removed with little change in operation.

If Q1 was changed to a MOSFET (eg BSS138) and the R3 removed the quiescent current would be almost zero. R2 could be shorted out and removed as well.

It is not a very good circuit as it relies upon the Hfe of Q2.

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