We found this circuit in the Texas Instruments optoelectronics manual. Field effect transistors can be BF245 and bipolar BC548. The sensor is a photodiode in the photo-generator mode.
The circuit shown consists of a simple tester for general purpose silicon or germanium diodes and...
This circuit was found in a 1987 documentation but uses components quite common in the current...
This configuration was found in a 1990s documentation. Modern operational amplifiers can be used...