I am using 2 x full wave active bridge circuits (kindly posted by ericgibbs) to monitor voltage signals from 2 seperate Current Transformers, which then feed into a Voltage Comparator - LM339 to eventually activate a relay output.
I need the output from one of the op amps to be reduced by 1 volt, to give a bias for the comparator, but am struggling acheiving this.
I thought initially that as per the attached LTSpice example, just put a potentiometer on the Op Amp output and reduce it accordingly.... but I realise that as the output voltage increases, the drop on the resitor increases and I lose the 1 Volt required difference.
I am sure that there is a simple answer to this and I am going to look really stupid, but here goes!
I need the output from one of the op amps to be reduced by 1 volt, to give a bias for the comparator, but am struggling acheiving this.
I thought initially that as per the attached LTSpice example, just put a potentiometer on the Op Amp output and reduce it accordingly.... but I realise that as the output voltage increases, the drop on the resitor increases and I lose the 1 Volt required difference.
I am sure that there is a simple answer to this and I am going to look really stupid, but here goes!