Found in Motorola documentation from the 90's, this circuit has a high input impedance. The power supply must be symmetrical. The circuit can be implemented with modern operational amplifiers.
This dimmer for 12 V incandescent lamps was found in a 1966 General Electric documentation. The circuit has...
This circuit was obtained in a 90s Popular Electronics. In the table the values of the components...
This circuit modifies the logical level of a digital function by switching to TTL, for example....