earckens
Member
...same ime Q3 out =0 drives Q4d =1...... Q4 gate is connected to Q2 source which is HIGH during detection... meaning Q4 is not conducting (p-channel high gate = not conducting), so Q4 drain is low.when noise occurs Q1 in is 1 Q1c is low the Q2D out is 1 then Q3-d out is 0 and LEd is On and. same ime Q3 out =0 drives Q4d =1 so if relay is between RELAY and 0V(GND) it is ON at the same time, but if between RELAY and +V it is inverted , assuming correct coil polarity in each case. so the schematic is correct.
If put in parallel with another sensor driver, the LED is ON externally driven.
Is this wrong? Where?
And because Q4 is p-channel I think the relay must be connected between Q4 drain and ground.