On 8/12/16 9:12 AM, Mr. Man-wai Chang wrote:
On 12/08/16 21:08, Jon Danniken wrote:

How long does the 3V need to last? What should happen if there is
another pulse during the desired "3V on" duration?

Jon


I want to flash a super-bright LED when there is an incoming phone
call. Talking about the good, old fixed-line telephone.



You mean to make something like this:
https://www.harriscomm.com/catalog/p...1fl4u6n28sqc57