Obtained in a 1969 Ferranti documentation, this circuit dissipates only 2.2 mW with 4.5 V. The circuit can be designed based on modern equivalent transistors.
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...