On Sun, 11 Jan 2004 13:55:44 -0500, "Len Krauss" wrote:

Hi Steve,
Thanks for that alram-out power limit tip and the excellent schematic!
Len

As usual, there's always a ton of ways to do any task.

The schmatic refered to above specifies a relay with as low as 120 Ohms coil resistance. At 12
Volts, this equates to 100 mills, meaning some heat will be generated, however small, inside the
GPS. I admit the alarm wouldn't be on very long in most cases, unless no one was aboard.

If it were me, I'd buffer the GPS output with the trusty 2N2222 to drive the relay. The advantage
is that it'd be trivial to incorporate a "alarm off" switch... and a sesitivity contol, just in case
the GPS output was analog (transistor, which I'd find hard to believe), and didn't have well-defined
logic levels.
Norm