Need hardware advice: ULN2003A

[Luciano]

Hi,

Some interesting stuff.

http://www.circuitcellar.com/library...9/c99cdpdf.pdf
http://www.circuitcellar.com/library.../c109cdpdf.pdf
http://www.circuitcellar.com/library...99/c1299cd.pdf

(In the first link they talk about the ULN2003A).

Best regards,

Luciano

[Christopher4187]

Thanks for the info. I actually read this yesterday when doing a search on the ULN2003. My test alarm has been cycling on and off for over 21 hours and has simulated 11 years (26,000 cycles) of operation. The ULN2003 and the relays are still working great; it's not what I would have expected without connecting pin number 9.