This circuit is suggested by National Semiconductor in its Linear Applications Handbook. The LM3909 integrated circuit consists of a very low consumption oscillator with a power supply of 1.2 V.
Found in old documentation about neon lamps, this circuit shows how to add a simple blown fuse...
This circuit was found in a 1980s documentation. It triggers a relay when liquid from a reservoir...
For counting to values higher than 16, many 4520 can be cascaded as shown in Figure . The EN...