IBM Technical Disclosure Bulletin (TDB 01-84 p.4091)
English (United States)
2 pages / 28.0 KB
Op-Amp Full-Wave Rectifier Circuit
This article describes an operational-amplifier (op-amp) full-wave rectifier circuit which eliminates the necessity of using an isolation transformer for sensing an AC signal and avoids using dual power supplies for the op-amp. The figure shows a full-wave rectifier circuit with two op-amp gates 10 and 11 to amplify the positive portion and to amplify/invert the negative portion of the AC input. Two diodes 12 and 13 logically "OR" the positive going output signals of the op-amp circuits. By using op-amps such as the LM 324 that can sense at levels below ground potential, dual power sources can be avoided. For example, the LM 324 is specified to sense levels as low as -0.3 volt. By tailoring the applied AC input to keep the signal small, i.e., less than Å0.2 volt, this op-amp can be utilized in both the inverting and noninverting modes to full-wave rectify the AC signal.