This interesting circuit for SMD assembly appeared in the November 1987 issue of Radio Electronics magazine. The phonons are generated by selected resistors that are fitted to the assembly.
If the input voltage falls below 12 V the LED glows up. Other voltages can be monitored by...
This motor control using transistors was found in a recent English publication. The circuit is for...
In the figure we have an electronic toy organ that can both serve to amuse children as a basis for...