This circuit uses a 7-segment display to indicate the logic level of a test circuit. The power supply is made with 5 V that can come from the analyzed circuit itself.
This circuit is from a Popular Electronics from 1993. The magazine is no longer printed, but the...
This circuit was obtained from the Texas Instruments component datasheet which can supply currents of...
This simple circuit uses small speakers for both listening and speaking (microphone). The feeding is...