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 interesting circuit of the American publication Electronics Handbook Volume XIII 1993 shows a...
This metering bridge circuit uses one power supply only. The operational ones depend on the...
The transistors of this timing circuit may be more modern types such as BC548 and BC558. The...