This simple circuit for headphones or small speakers was found in documentation from the 90s. The circuit works with voltages from 5 to 9 V and has good gain.
The integrated circuits used in this 1999 project are not very common today. However, they can be...
This 3-digit thermometer, suggested by Texas Instruments, uses 3 integrated plus the display, with...
This circuit is from the National Semiconductor FET Databook. The coil data is provided with the...