Found in Datel's documentation from the 1980s, this circuit makes use of the company's operational amplifiers. The circuit can be implemented with any modern equivalent operational.
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...