modify constant to momentary

Hi Guys, I need a momentary output from a constant negative supply which seems simple enough, but then I need another momentary output when the negative supply switches off. The only problem is that I don't want constantly energised relay coils one way or the other, if that make sense? Any help on the best way to achieve this would be great :)

Solid state circuitry. IE - electronics; whether logic chips or discrete transistors etc.

Thanks for your reply. Do you know of any specific circuits that might work for my situation? I'm not too familiar with solid state stuff :)

Pulse Doubler using 4538 PULSE DOUBLER with 74123 & 7486 Simple MAXIM Circuit Doubles Input Frequency

what exactly are you trying to doooo?

https://www.the12volt.com/installbay/forum_posts.asp~TID~126322~PN~1

Try this one. Let me know if it works.

John DeRosa (Hotwaterwizard)

Stockton California

When in doubt, try it out !