This circuit was found in a 73 amateur radio magazine from the 90s. An LED extends the scale from 0 to 5 V to 10 to 15 V in this bargraph circuit. Other zener values can be used.
This circuit was obtained from a European magazine of the 1990s. The integrated circuit used is...
Using a ceramic resonator, it is possible to vary the frequency between 4.9 MHz and 5 MHz. The...
In the figure we have the way to obtain a monostable action by lighting an LED for a certain time...