This circuit, which can be seen elsewhere on this website, was obtained from a 90’s English documentation. The circuit drives a small speaker, but for greater volume an external amplifier must be used.
We found this chopper circuit in a 1967 publication. The transistors are of the time, and current...
This circuit was found in a 1977 Radio Handbook. The ports used are CMOS like 4001 and the...
Ohmite TGHD non Inductive High Power Resistors Available in SOT-227 enclosures, these Ohmite...