This circuit is used in magnetic tape recorders, having been found in documentation in the 1960s. The circuit uses Japanese transistors, and the critical components are transformers.
This circuit from a National Semiconductor manual from the 1980s shows how to use the LM388, a...
This circuit was found in the December 1992 Radio Electronics magazine. Range depends on optical...
In the figure we show a widely used configuration for the CA3140. The power of this circuit can be...