This constant current charger from 1997 Linear Technology Applications uses common components at the time. The transformer is the critical component, being designed according to the load voltage.
This circuit is from a 1977 Radio Shack documentation. In it we have the activation of an LED for...
This circuit was suggested by National Semiconductor in one of its manuals. The LM108 integrated...
We found this circuit in a 1981 publication. Its purpose is to measure resistances of very low...