This 1967 General Electric circuit makes use of an array of 3 (integrated) transistors for an amplifier stage. The circuit has a 500 mV output.
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...