This simple bridge circuit can be used for impedance or resistance measurement using a high impedance earphone as an indicator. The circuit is from an American 80's documentation.
This circuit causes the light of a bicolor LED to change when it is turned on. The time of...
This circuit is from an old National Semiconductor component manual. The circuit can be...
This circuit tests crystals up to a few megahertz with ease. The circuit is from a 1977...