This circuit was found in a 73 amateur radio magazine from the 90s. An LED extends the scale from 0 to 5 V to 10 to 15 V in this bargraph circuit. Other zener values can be used.
The purpose of this circuit, which we found in the November 1986 Radio Electronics issue, is to...
This circuit was found in an 80's Electronic Design. The frequency depends on the crystal and the...
This switching regulator circuit with less than 100 mV ripple was found in a 1980s documentation. The...