The integrated circuit of this amplifier is not very common today. The output transistors can be TIP31 and TIP32 in heat radiators. The circuit is from the 1977 National Semiconductor Audio Handbook.
This circuit is a telephone line simulator and can be used for internal communications. It is...
This digital didactic digit counter uses common TTL integrated circuits and a common anode...
This reflectometer or standing-wave ratio meter (SWR) was found in a 1980s American documentation. The...