Diode circuit fed with voltage follower doesnt work
I believe you could accomplish your goal by making R5 large (> 4.7k for the LM385 Op Amp to not be loaded to heavily.) and placing a diode from ground to the junction of R5 and the + terminal on U2. This would pull the -12 to ~0V and leave the +12 alone. The only issue is if this is working at high frequency > 1MHz, the parasitic capacitance of the diode could start to affect it.







simulate this circuit &ndash; Schematic created using CircuitLab