This circuit was found in an American 1980s documentation. It analyzes the exhaust gas of a vehicle using a special sensor. The indicator is a milliamperimeter.
This circuit using an operational amplifier was found in old American documentation. It can be...
This is a voltmeter with high input resistance. The transistor is germanium. We found it in an...
Two NAND gates are used in the configuration shown here to perform as a monostable triggered by...