Found in an old English publication, this circuit applies to the 240 V network, but can be changed to lower voltages. Transistors are mostly general-purpose, admitting modern equivalents.
Found in a magazine from the '90s, this circuit uses an integrated circuit from the era that is...
This circuit, found in documentation from the 1990s, uses a common 7-segment LED display. The...
This circuit provides precise signals of three frequencies, using CMOS technology. The integrated...