I am trying to come up with a circuit that will do the following:
1. Monitor an input pulse signal, a fuel injector pulse in this case.
2. When a pulse in recieved on the input, trigger to output signal for 1 sec.
That is the easy part, I am guessing that a simple 555 set up in monostable mode with the appropriate R and C for a 1 second delay. This will give me a one second pulse when the input triggers.
This is the part I cannot figure out:
3. When another pulse arrives on the input after the 555 has already been triggered, I want the 1 second count reset so that the output of the 555 remains high as long as there is at least one pulse per second.
If there is a better approach to this please let me know. At the end of the day I need a circuit that will monitor an digital input, as long as that input has pulse activity at least once per second then single output of this circuit will remain high. After activity on the input has ceased for one second the output goes low.
Any comments would be appreciated, thanks.
Just a though, what would be the effect of tying the trigger and reset pins together?
1. Monitor an input pulse signal, a fuel injector pulse in this case.
2. When a pulse in recieved on the input, trigger to output signal for 1 sec.
That is the easy part, I am guessing that a simple 555 set up in monostable mode with the appropriate R and C for a 1 second delay. This will give me a one second pulse when the input triggers.
This is the part I cannot figure out:
3. When another pulse arrives on the input after the 555 has already been triggered, I want the 1 second count reset so that the output of the 555 remains high as long as there is at least one pulse per second.
If there is a better approach to this please let me know. At the end of the day I need a circuit that will monitor an digital input, as long as that input has pulse activity at least once per second then single output of this circuit will remain high. After activity on the input has ceased for one second the output goes low.
Any comments would be appreciated, thanks.
Just a though, what would be the effect of tying the trigger and reset pins together?