The purpose of this circuit is only to increase the input resistance of a multimeter, since there is no voltage gain. The batteries are 9 V and operational equivalents can be used.
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...