I am planning to make a simple integer adder/multiplier which needs a variable frequency, comparatively slow clock (around 1 to 200 Hz) for demonstration purposes. I used the following generic 555 timer circuit to generate the required clock signal.
(Add more D flip-flops if more bits needed)
I want to pause the clock when the circuit detects a data overflow (sending a 3V logic signal) to stop the calculation process and hold its states. Not being the most familiar with electronics, I tinkered around in Falstad and noticed if you interrupt the connection between output and the "feedback" rail (Trigger, Threshold, and C1) , the timer will be stuck in its current state. The circuit will then be like such:
So, let me divide my question into two parts:
1. Can I simply use a switch (say, a BJT or a relay) to interrupt the the feeback rail to pause the clock?
2. Can I simply use BJTs or MOSFETs as the switch here? If not, can I use BJT-based octocouplers? The simulation from Falstad shows that BJTs/MOSFETs interfere with the clock signal.