Using transistors at the time, this circuit was found in a 1970s documentation. Transistors support modern equivalents for 2A currents at least in the case of the output transistors.
This circuit was found in a 1989 publication. The operational amplifier supports equivalents. The...
This humidity sensor indicates the different levels of conduction of the sensors through an LED...
Found in documentation from the 70s, this circuit uses components from that time. Some of these...