The frequency of each note depends on R2, which must be replaced by a keyboard. The circuit is from Radio Electronics from April 1980. The power supply is 9 V for the amplifier used.
Applying a high voltage to a mixed lamp can obtain a bluish light with a decorative effect. This...
We found this transistorized AM receiver of the regenerative type of excellent quality in a...
This circuit indicates the logical level of a CMOS circuit, extracting the power from the circuit...