With this circuit it is possible to visualize the characteristic curve of a component on an oscilloscope. The circuit is from a Popular Electronics from the 90s.
This receiver for infrared remote control was found in the Philips Databook of 1990, The circuit...
Found in an English publication from the 1980s, this circuit uses components that are still common...
This circuit was found in Maxim's documentation from the 90's. The frequency of the circuit is...