This precision full-wave rectifier used in instrumentation was found in a technical documentation from the 1980s. Diodes are general-purpose types.
The circuit shown is from the National Semiconductor Linear Applications Handbook of 1994. using...
This photometer with bargraph indication by LEDs was obtained in a publication in 1997. The sensor...
The amplifier in the figure is based on a single LM108 and has low noise compensation. In this...