Suggested by National Semiconductor in documentation from the 90s, this circuit uses a switched regulator of the time. The circuit is suitable for NiCad battery charges.
This circuit uses an unusual PLL, the 4046 CMOS. We found it in the October 1994 issue of...
This alarm circuit was found in a 1989 Poptronics, but all the components used are common, as the...
We found this circuit in a 1995 documentation. It can measure frequencies from 100 kHz to over 100 MHz...