Reverse polarity protection for PNP circuits?

[soggybag]

I'm working a BMP with PNP transistors. I have a PCB that uses 1N5817 in series for reverse polarity protection. I want to use this board, I'm guessing I need to:

- flip the 1n5817
- reverse any polarized caps
- and reverse the power connection

Do I have that right or did I miss something?

[antonis]

Keep diode polarity the same and reverse cap(s) polarity..

[soggybag]

Thanks for the reply. Can I follow up by asking if the reverse protection diode would work where that 100r resistor is, with the cathode facing the AC Adapter?

[antonis]

Series reverse protection diode should always face from higher to lower voltage..
(it doesn't care for what we name GND or +/- 9V..)

Here, conventional current flow is from GND to 9V battery minus(-) and through battery to (+)..
So, diode in place of 100R resistor should face to AC adaptor 'cause GND "pushes" current out..

hint: When in doubt about current flow, observe BJTs Emitter arrow direction..

[toneman]

The battery polarity indicators are reversed!

Short line = neg
Long line = pos