I am using a 9v ac supply to power 1a 5v supply (fw bridge and 1000uc cap and 5v regulator) and using the same supply for generating square wave 60hz timing pulse. I have tried 741 op amp zero crossing but the low voltage output of 741 is at 1.2v, not enough to trigger a 74ls14 chip to high state. I am experimenting with a simple transistor circuit using 2n3904c but the ac input does not go below 5v no matter which side of the ac input I use.
this circuit has worked in the past. Is this a sign of shorted components?
this circuit has worked in the past. Is this a sign of shorted components?