Operating at just 1.35 V this circuit was found in a 1969 Electronic Design. The circuit makes use of transistors of the time but can be implemented with current equivalents.
This circuit that simulates the sound of a drum is part of an article published in the Radio...
This circuit was obtained from an Application Note from Linear Technology that manufactures the used...
This is a well-known RC oscillator configuration using a 741 operational amplifier. The circuit is from...