for Eric

[Anonymous]

Hello all: I see in the circuits of induction of pulses the distributed source to feed the operational IC in some cases the tensions are simetrics and in other cases they are not it, harms in something, sensitivity this difference. In addition the adjustment to ofset in this cases in that value must be? in 0 volts with respect to the positive tension? Thanks
Carlos

 

[Anonymous]

Hi Carlos,
I'm not quite clear what you are asking, but I will take a guess. The front end amplifier can be connected either as a single ended input, or as a differential. I have tried both, but settled on a single ended arrangement. I used a differential on a version of the Deepscan I made some years ago, with a twin screened cable to the coil instead of coax. Differential inputs are good for cancelling common mode noise, but there is not much of that as the noise picked up on the coil appears as a differential signal to the amplifier.
Where the amplifier output is referenced to, depends on the power supply arrangement. I usually reference it to the battery positive, which is taken to be the electronics ground. In this case you adjust the offset to be 0V referenced to this. If you use a P channel Mosfet, then you can reference it to battery negative (more conventional), however your choice of Mosfets is more limited.
Eric.