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.
Found in a 1964 CQ magazine this circuit consists of an automatic telegraphic key, providing the...
This is the minimum amplifier configuration with the LM380 and can provide an output of up to 2.5...
The UM3562 integrated circuit (not very easy to find) synthesizes three types of sound that...