aibelectronics
Member level 2
**broken link removed**
please does anyone know how the LM 3914 zero crossing detector in the above schematic work? the working of the 3914 remains a mystery to me, I understand as the input signal rises a 'coincidence' comparator lights up an LED when there's a match b/w the reference voltage and the value of the signal at that point in time. A comparator now we know, swings to Vcc when there's a coincidence at its inputs, wouldn't this then make the LED cathode just as positive as its anode?
How then does it light up?
No.2 How exactly does the full wave rectifier function? I understand the rectification process when the signal is positive, but for the -ve it just doesn't add up, from my analysis the rectifier would form an inverting amplifier of unity gain in the negative region, but it seems they used the equation for a non-inverting amplifier to come up with the solution...
thanks in advance!
please does anyone know how the LM 3914 zero crossing detector in the above schematic work? the working of the 3914 remains a mystery to me, I understand as the input signal rises a 'coincidence' comparator lights up an LED when there's a match b/w the reference voltage and the value of the signal at that point in time. A comparator now we know, swings to Vcc when there's a coincidence at its inputs, wouldn't this then make the LED cathode just as positive as its anode?
How then does it light up?
No.2 How exactly does the full wave rectifier function? I understand the rectification process when the signal is positive, but for the -ve it just doesn't add up, from my analysis the rectifier would form an inverting amplifier of unity gain in the negative region, but it seems they used the equation for a non-inverting amplifier to come up with the solution...
thanks in advance!