No worries, thanks!It’s close to midnight here in the UK, if no-one else provides a circuit solution for you – I’ll post one tomorrow.
Perfect, I'll put this together and report back.OK, simply add a unity gain inverting op-amp to the output of circuit.
With 8 pin packages containing 2 op-amps available, it will add minimal additional components.
The second inverting op-amp would be configured exactly as the first, except that the input and feedback resistors would both be 10kΩ, resulting in inverting unity gain. To correct for the fact that the output voltage is not equal about 3V, the voltage divider resistor connected from the non-inverting input to 0V should be reduced to 6.8kΩ (from 10kΩ).
The gain you need is not 10 it is::I got this built, it's working very well indeed. And fully adjustable too. Do I need to worry about decoupling of filtering capacitors?
Unless you want an OFF/ON output DO NOT use a comparator. Use a non-inverting opamp circuit with an offset adjustment and a gain adjustment. I see that you have already been given the exact values, no need for me repeat that part.Use a comparator with a reference set to about 3V.
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