This circuit of dozens of watts uses germanium transistors and the critical components are transformers. The circuit is from the 1960 Mullard transistor application manual.
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...