Hi,
I have found a simple metal detector circuit which i have simulated here:
MD CIRCUIT
Here is a pic of the full schematic:
I was hoping someone could tell me roughly how it works.
I understand the 555 timer that generates a pulse width and frequency of the 9 volt battery short over the coil.
I understand the damping resister in paralell with the coil.
I understand the clamper diodes and the preamp stage (opamp 1).
What i dont understand is the next opamp stage.
It is set up as a comparator and compares the amplified flyback decay signal from the coil with what?
If someone could explain in simple terms the final stages of this circuit it would be greatly appreciated.
Thanks
I have found a simple metal detector circuit which i have simulated here:
MD CIRCUIT
Here is a pic of the full schematic:
I was hoping someone could tell me roughly how it works.
I understand the 555 timer that generates a pulse width and frequency of the 9 volt battery short over the coil.
I understand the damping resister in paralell with the coil.
I understand the clamper diodes and the preamp stage (opamp 1).
What i dont understand is the next opamp stage.
It is set up as a comparator and compares the amplified flyback decay signal from the coil with what?
If someone could explain in simple terms the final stages of this circuit it would be greatly appreciated.
Thanks