This circuit was found in a Ferranti documentation from 1969. The transistors are common types of the company at the time. Smaller equivalents may be used. The output power is of the order of 150 mW.
This circuit found in a 1964 US publication reverses the signal level by providing 9 to 0 V...
This charger can be used with one to four AA, AAA, C or D cells. The maximum current is given by R...
This ultra-low consumption circuit was originally designed to be powered by a solar panel or small...