I have a beam break detector circuit which drives the circiut belowView attachment 64551
The output of the timer pin 3 drives a relay making an alarm ring. However, I now realise the alarm cannot be on forever, so I need to have a timer to turn it off. I realise now I should have just had a variable timer circuit doing the operation in one go.
However I have now made another timer using a 555, which I intended to start up at the same time as the circuit above is triggered, and use it's output to put a low on the circuit above reset line.
But, I have a worry that if the output of timer two is strapped accross the reset line to begin with, then the first circuit will reset before it's started. Just wondering if anyone has an idea other than me messing my stripboard up even further to convert my first circuit into a straight timer.
Thanks
The output of the timer pin 3 drives a relay making an alarm ring. However, I now realise the alarm cannot be on forever, so I need to have a timer to turn it off. I realise now I should have just had a variable timer circuit doing the operation in one go.
However I have now made another timer using a 555, which I intended to start up at the same time as the circuit above is triggered, and use it's output to put a low on the circuit above reset line.
But, I have a worry that if the output of timer two is strapped accross the reset line to begin with, then the first circuit will reset before it's started. Just wondering if anyone has an idea other than me messing my stripboard up even further to convert my first circuit into a straight timer.
Thanks