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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>My electric fence monitoring project is making progress.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Attached is a scope shot of the signal I am trying to monitor.<o:p></o:p></p><p class=MsoNormal>There are two issues I want to address before putting this signal on the A0 pin of my ESP8266 development board (D1 mini).<o:p></o:p></p><p class=MsoNormal>The spike to ~5 volts is concerning. I think I can use a 3.3v Zener diode to suppress this. Installed between my signal and ground with the banded end away from ground.<o:p></o:p></p><p class=MsoNormal>The negative lobe of the signal is also concerning. Can I just use a diode in series here? Banded end toward the A0 pin. I can adjust the voltage up a bit to compensate<o:p></o:p></p><p class=MsoNormal>for voltage drop across the diode.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I have drawn up a schematic of what I think is the solution.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks for any comments.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>---> Paul<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>