This circuit can be used in a signal level indicator with LEDs. The circuit is from an Electronics Now dated January 1996. The power supply must be dual.
This configuration from the 1970s can be applied to modern equivalent operational amplifiers. The...
This simple alarm using only transistors was found in a 1990 publication. It can be powered by D...
The circuit presented was found in the 1994 National Instruments Linear Applications Handbook and...