Found in documentation from the 1980s, this circuit uses a SG1524. It is an uncommon integrated circuit nowadays. The circuit provides a current of 20 mA with a symmetrical voltage between 15 and 18 V.
The XR220 is a circuit equivalent to the 555 of the 1970s. This configuration from Radio...
Found in an English publication from the 1960s, this circuit uses period components, including the...
This circuit was found in Linear Circuits Applications of Texas Instruments, originally using the...