I have a circuit that powers some leds when vibrations are detected. I am trying to integrate a PMOS for reverse polarity battery protection.

When the PMOS is present the circuit simulation fails as soon as the piezo (simulated using V1+R1) sine wave starts i.e. TDelay secs. Without the PMOS the circuit works as expected but I don't have any reverse polarity protection.

Is the piezo closing the PMOS?

Area with PMOS and Piezo

The full circuit Full Circuit

  • \$\begingroup\$ M2 P/N is Pch but schematics shows Nch Why? \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Mar 9 '19 at 17:51
  • \$\begingroup\$ If M2 really is a PMOS then you need to connect its source to the V2 supply. \$\endgroup\$ – Elliot Alderson Mar 9 '19 at 18:00
  • \$\begingroup\$ yes it is a PMOS, i followed the example from link for how to connect it for this purpose \$\endgroup\$ – user1247060 Mar 9 '19 at 18:09
  • \$\begingroup\$ Ah, OK I see what you are doing. \$\endgroup\$ – Elliot Alderson Mar 9 '19 at 18:13

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