I have an animal trap that is a spring activated device, and I am planning a circuit that would call me when it has been activated.
The spring of the trap is part of a circuit, and when the spring retracts it opens the circuit. So I get for example 5V when the device has not been activated, which falls to zero volts when the trap is activated.
I have soldered some wires to one of the buttons of an old phone and added speed dial to that button so the phone calls me when the button is pressed for a couple of seconds. The problem is that if the button is down for a long time, it screws up the phone and it has to be restarted. Not a big deal, but annoying.
So I would like to put a timer between the trap and the phone. Now my problem with timers, like the 555 is that if the input is very long then the timers output does not change state even after its set time. So how to make a timer that would work with very long input signals?
The spring of the trap is part of a circuit, and when the spring retracts it opens the circuit. So I get for example 5V when the device has not been activated, which falls to zero volts when the trap is activated.
I have soldered some wires to one of the buttons of an old phone and added speed dial to that button so the phone calls me when the button is pressed for a couple of seconds. The problem is that if the button is down for a long time, it screws up the phone and it has to be restarted. Not a big deal, but annoying.
So I would like to put a timer between the trap and the phone. Now my problem with timers, like the 555 is that if the input is very long then the timers output does not change state even after its set time. So how to make a timer that would work with very long input signals?
