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 Texas Instruments LM5178 Buck-boost controller is capable of operating in the 4.2 to 55 V (60...
This 1970 Philips circuit uses a mechanical counter. The circuit is triggered by a reed switch...
This 1 MHz oscillator was found in an Electronics World of 1969. The circuit uses a...