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 of a 1991 PE Hobbyst Handbook allows the brightness of the incandescent lamp to be...
This circuit is from the old RCA transistors manual of 1964. The transistor can be the BC558 and...
Originally this circuit is from an English magazine, but I found it in Argentina's Radio Chassis...