Help for Uber Newbie - GPS trigger

Pretty simple task to work out the pulse delay thingee. A one shot multivibrator and some logic gates can seperate the short pules from a long one. Of course these days an 8 pin PIC would probably be the best solution. Now getting a pulse to send an E-mail is software magic that I don't have a clue about, but of course I know it can be done.

Send the email is simple, once you have the hardware figure out. You can have a socket connection to your mail server's smtp port. To do so, you must have hardware like GSM/GPRS radio. Anything can be done, with the right price of course.

As I understand it in general terms, you have a horn "output" that you want to use to control something, if, and only if, that output is active for longer than a "chirp". You mentioned RC and a relay, so this circuit is designed with that in mind.

• ----+------------+-----+ | | | | 1N4001 [D1] [Rly] Omron G5LE-14-DC12 | |a | | +-----+ | | P --- 500K O

Thank you for all your answers to everyone who responded. I had already written a response, but Firefox crashed and I did not get a chance to send it off, so this will be brief. The GPS unit looks for a negative input, which causes a notification to be sent by e-mail. The relay should stay energized for about 5-10 minutes even after the drop in the horn pulse to prevent an overload of e-mail notifications to be sent.

Ok, that requires something different. You can still use the TL431 circuit, but have it trigger a timer. Replace the relay with a 1K resistor and eliminate D1, like this:

• from battery---+-------------------+ | | + ----+---->|----+ | | | D1 | | ----- | P [1K] [10K] +---1| |8-+------+ 500K O to GPS

Build a 555 monostable that is powered from the battery (not the horn - the TL431 circuit still gets power from the horn relay). Tie pin 2 of the 555 to + from the battery through a 10K resistor, and to the TL431 circuit as above. You can find the 555 circuit here:

Ed